Philip G. Janicak, MD

Neuroscience research over the past half century has failed to significantly advance the treatment of severe mental illness.^1,2 Hence, evidence that a longer duration of untreated psychosis (DUP) aggravates—and early intervention with medication and social supports ameliorates—the long-term adverse consequences of psychotic disorders generated a great deal of interest.^3,4 This knowledge led to the development of diverse early intervention services worldwide aimed at this putative “critical window.” It raised the possibility that appropriate interventions could prevent the long-term disability that makes chronic psychosis one of the most debilitating disorders.^5,6 However, even beyond the varied cultural and economic confounds, it is difficult to assess, compare, and optimize program effectiveness.⁷ Obstacles include paucity of sufficiently powered, well-designed randomized controlled trials (RCTs), the absence of diagnostic biomarkers or other prognostic indicators to better account for the inherent heterogeneity in the population and associated outcomes, and the absence of modifiable risk factors that can guide interventions and provide intermediate outcomes.^4,8-10

To better appreciate these issues, it is important to distinguish whether a program is designed to prevent psychosis, or to mitigate the effects of psychosis. Two models include the:

• Prevention model, which focuses on young individuals who are not yet overtly psychotic but at high risk
• First-episode recovery model, which focuses on those who have experienced a first episode of psychosis (FEP) but have not yet developed a chronic disorder.

Both models share long-term goals and are hampered by many of the same issues summarized above. They both deviate markedly from the standard medical model by including psychosocial services designed to promote restoration of a self-defined trajectory to greater independence.^11-14 The 2 differ, however, in the challenges they must overcome to produce their sample populations and establish effective interventions.^10,15,16

In this article, we provide a succinct overview of these issues and a set of recommendations based on a “strength-based” approach. This approach focuses on finding common ground between patients, their support system, and the treatment team in the service of empowering patients to resume responsibility for transition to adulthood.

The prevention model

While most prevention initiatives in medicine rely on the growing ability to target specific pathophysiologic pathways,³ preventing psychosis relies on clinical evidence showing that DUP and early interventions predict a better course of severe mental illness.¹⁷ In contrast, initiatives such as normalizing neonatal neuronal pathways are more consistent with the strategy utilized in other fields but have yet to yield a pathophysiologic target for psychosis.^3,18

Initial efforts to identify ‘at-risk’ individuals

The prevention model of psychosis is based on the ability to identify young individuals at high risk for developing a psychotic disorder (Figure). The first screening measures were focused on prodromal psychosis (eg, significant loss of function, family history, and “intermittent” and “attenuated” psychotic symptoms). When applied to referred (ie, pre-screened) samples, 30% to 40% of this group who met criteria transitioned to psychosis over the next 1 to 3 years despite antidepressant and psychosocial interventions.¹⁹ Comprising 8 academic medical centers, the North American Prodrome Longitudinal Study (NAPLS) produced similar results using the Structured Interview for Prodromal Syndromes (SIPS).¹⁷ Thus, 30% to 50% of pre-screened individuals referred by school counselors and mental health professionals met SIPS criteria, and 35% of these individuals transitioned to psychosis over 30 months. The validity of this measure was further supported by the fact that higher baseline levels of unusual thought content, suspicion/paranoia, social impairment, and substance abuse successfully distinguished approximately 80% of those who transitioned to psychosis. The results of this first generation of screening studies were exciting because they seemed to demonstrate that highly concentrated samples of young persons at high risk of developing psychosis could be identified, and that fine-tuning the screening criteria could produce even more enriched samples (ie, positive predictive power).

CP02010012_f1.PNG

Initial interventions produced promising results

The development of effective screening measures led to reports of effective treatment interventions. These were largely applied in a clinical staging model that restricted antipsychotic medications to those who failed to improve after receiving potentially “less toxic” interventions (eg, omega-3 polyunsaturated fatty acids and other antioxidants; psychotherapy; cognitive-behavioral therapy [CBT]; family therapy).⁵ While study designs were typically quasi-experimental, the interventions appeared to dramatically diminish the transition to psychosis (ie, approximately 50%).

Continue to: The first generation...

The first generation of RCTs appeared to confirm these results, although sample sizes were small, and most study designs assessed only a single intervention. Initial meta-analyses of these data reported that both CBT and antipsychotics appeared to prevent approximately one-half of individuals from becoming psychotic at 12 months, and more than one-third at 2 to 4 years, compared with treatment as usual.²⁰

While some researchers challenged the validity of these findings,^21-23 the results generated tremendous international enthusiasm and calls for widespread implementation.⁶ The number of early intervention services (EIS) centers increased dramatically worldwide, and in 2014 the National Institute for Health and Care Excellence released standards for interventions to prevent transition to psychosis.²⁴ These included close monitoring, CBT and family interventions, and avoiding antipsychotics when possible.²⁴

Focusing on sensitivity over specificity

The first generation of studies generated by the prevention model relied on outreach programs or referrals, which produced small samples of carefully selected, pre-screened individuals (Figure, Pre-screened) who were then screened again to establish the high-risk sample.²⁵ While approximately 33% of these individuals became psychotic, the screening process required a very efficient means of eliminating those not at high-risk (given the ultimate target population represented only approximately .5% of young people) (Figure). The pre-screening and screening processes in these first-generation studies were labor-intensive but could only identify approximately 5% of those individuals destined to become psychotic over the next 2 or 3 years. Thus, alternative methods to enhance sensitivity were needed to extend programming to the general population.

Second-generation pre-screening (Figure; Step 1). New pre-screening methods were identified that captured more individuals destined to become psychotic. For example, approximately 90% of this population were registered in health care organizations (eg, health maintenance organizations) and received a psychiatric diagnosis in the year prior to the onset of psychosis (true positives).⁸ These samples, however, contained a much higher percentage of persons not destined to become psychotic, and somehow the issue of specificity (decreasing false positives) was minimized.^8,9 For example, pre-screened samples contained 20 to 50 individuals not destined to become psychotic for each one who did.²⁶ Since screening measures could only eliminate approximately 20% of this group (Figure, Step 2, page 25), second-generation transition rates fell from 30% to 40% to 2% to 10%.^27,28

Other pre-screening approaches were introduced, but they also focused on capturing more of those destined to become psychotic (sensitivity) than eliminating those who would not (specificity). For instance, Australia opened more than 100 “Headspace” community centers nationwide designed to promote engagement and self-esteem in youth experiencing anxiety; depression; stress; relationship, work, or school problems; or bullying.¹³ Most services were free and included mental health staff who screened for psychosis and provided a wide range of services in a destigmatized setting. These methods identified at least an additional 5% to 7% of individuals destined to become psychotic, but to our knowledge, no data have been published on whether they helped eliminate those who did not.

Continue to: Second-generation screening

Second-generation screening (Figure, Step 2). A second screening aims to retain those pre-screened individuals who will become psychotic (ie, minimizing false negatives) while further minimizing those who do not (ie, minimizing false positives). The addition of cognitive, neural (eg, structural MRI; neurophysiologic), and biochemical (eg, inflammatory immune and stress) markers to the risk calculators have produced a sensitivity close to 100%.^8,9 Unfortunately, these studies downplayed specificity, which remained approximately 20%.^8,9 Specificity is critical not just because of concerns about stigma (ie, labeling people as pre-psychotic when they are not) but also because of the adverse effects of antipsychotic medications and the effects on future program development (interventions are costly and labor-intensive). Also, diluting the pool with individuals not at risk makes it nearly impossible to identify effective interventions (ie, power).^27,28

While some studies focused on increasing specificity (to approximately 75%), this leads to an unacceptable loss of sensitivity (from 90% to 60%),²⁹ with 40% of pre-screened individuals who would become psychotic being eliminated from the study population. The addition of other biological markers (eg, salivary cortisol)³⁰ and use of learning health systems may be able to enhance these numbers (initial reports of specificity = 87% and sensitivity = 85%).^8,9 This is accomplished by integrating artificial and human intelligence measures of clinical (symptom and neurocognitive measures) and biological (eg, polygenetic risk scores; gray matter volume) variables.³¹ However, even if these results are replicated, more effective pre-screening measures will be required.

Identifying a suitable sample population for prevention program studies is clearly more complicated than for FEP studies, where one can usually identify many of those in the at-risk population by their first hospitalization for psychotic symptoms. The issues of false positives (eg, substance-induced psychosis) and negatives (eg, slow deterioration, prominent negative symptoms) are important concerns, but proportionately far less significant.

Prevention and FEP interventions

Once a study sample is constituted, 1 to 3 years of treatment interventions are initiated. Interventions for prevention programs typically include CBT directed at attenuated psychosis (eg, reframing or de-catastrophizing unusual thoughts and minimizing distress associated with unusual perceptions); case management to facilitate personal, educational, and vocational goals; and family therapy in single or multi-group formats to educate one’s support system about the risk state and to minimize adverse familial responses.¹⁴ Many programs also include supported education or employment services to promote reintegration in age-appropriate activities; group therapy focused on substance abuse and social skills training; cognitive remediation to ameliorate the cognitive dysfunction; and an array of pharmacologic interventions designed to delay or prevent transition to psychosis or to alleviate symptoms. While most interventions are similar, FEP programs have recently included peer support staff. This appears to instill hope in newly diagnosed patients, provide role models, and provide peer supporters an opportunity to use their experiences to help others and earn income.³²

The breadth and depth of these services are critical because retention in the program is highly dependent on participant engagement, which in turn is highly dependent on whether the program can help individuals get what they want (eg, friends, employment, education, more autonomy, physical health). The setting and atmosphere of the treatment program and the willingness/ability of staff to meet participants in the community are also important elements.^11,12 In this context, the Headspace community centers are having an impact far beyond Australia and may prove to be a particularly good model.¹³

Continue to: Assessing prevention and FEP interventions

The second generation of studies of prevention programs has not confirmed, let alone extended, the earlier findings and meta-analyses. A 2020 report concluded CBT was still the most promising intervention; it was more effective than control treatments at 12 and 18 months, although not at 6, 24, or 48 months.³³ This review included controlled, open-label, and naturalistic studies that assessed family therapy; omega-3 polyunsaturated fatty acids; integrated psychological therapy (a package of interventions that included family education, CBT, social skills training, and cognitive remediation); N-methyl-D-aspartate receptor modulators; mood stabilizers; and antipsychotics. In addition to the evidence supporting CBT, the results also indicated nonsignificant trends favoring family and integrated psychological therapy. Neither a 2019 Cochrane review³⁴ nor a 2020 “umbrella” assessment of 42 meta-analyses⁹ found convincing evidence for the efficacy of any program components.

While these disappointing findings are at least partly attributable to the methodological challenges described above and in the Figure, other factors may hinder establishing effective interventions. In contrast to FEP studies, those focused on prevention had a very ambitious agenda (eliminating psychosis) and tended to downplay more modest intermediate outcomes. These studies also tended to assess new ideas with small samples rather than pursue promising findings with larger multi-site studies focused on a group of interventions. The authors of a Cochrane review observed “There is the impression that in this whole area there is a triumph of hope over adversity. There is the repeated hope invested in another—often unique—study question and then a study of fewer than 100 participants are completed. This results in the set of comparisons reported here, all 9 of which are too underpowered to really highlight clear differences.”³⁴ To use a baseball analogy, it seems that investigators are “swinging for the fence” when a few singles are what’s really needed.

From the outset, the goals of FEP studies were more modest, largely ignoring the task of developing consensus definitions of recovery that require following patients for up to 5 to 10 years. Instead, they use intermediate endpoints based on adapting treatments that already appeared effective in patients with chronic mental disorders.³⁵ As a consequence, researchers examining FEP demonstrated clear, albeit limited, salutary effects using large multi-site trials and previously established outcome measures.^3,10,36 For instance, the Recovery After an Initial Schizophrenia Episode-Early Treatment Program (RAISE-ETP) study was a 2-year, multi-site RCT (N = 404) funded by the National Institute of Mental Health (NIMH). The investigators reported improved indices of social function (eg, quality of life; education and work participation) and total ratings of psychopathology and depression compared with treatment as usual. Furthermore, they established that DUP predicted treatment response.³⁵ The latter finding was underscored by improvement being limited to the 50% with <74 weeks DUP. Annual costs of the program per 1 standard deviation improvement in quality of life were approximately $1,000 for patients with <74 weeks DUP and $40,000 for those with >74 weeks DUP. Concurrent meta-analyses confirmed and extended these findings,¹⁶ showing higher remission rates; diminished relapses and hospital admissions; greater engagement in programming; greater involvement in work and school; improved quality of life; and other steps toward recovery. These studies were also able to establish a clear benefit of antipsychotic medications, particularly a high acceptance of long-acting injectable antipsychotic formulations, which promoted adherence and decreased some adverse events³⁷; and early use of clozapine therapy, which improved remission rates and longer-term outcomes.³⁸ Other findings underscored the need to anticipate and address new problems associated with effective antipsychotic therapy (eg, antipsychotic response correlates with weight gain, a particularly intolerable adverse event for this age group).³⁹ Providing pre-emptive strategies such as exercise groups and nutritional education may be necessary to maintain adherence.

Limitations of FEP studies

The effect sizes in these FEP studies were small to medium on outcome measures tracking recovery and associated indicators (eg, global functioning, school/work participation, treatment engagement); the number needed to treat for each of these was >10. There is no clear evidence that recovery programs such as RAISE-ETP actually reduce longer-term disability. Most studies showed disability payments increased while clinical benefits tended to fade over time. In addition, by grouping interventions together, the studies made it difficult to identify effective vs ineffective treatments, let alone determine how best to personalize therapy for participants in future studies.

The next generation of FEP studies

While limited in scope, the results of the recent FEP studies justify a next generation of recovery interventions designed to address these shortcomings and optimize program outcomes.³⁹ Most previous FEP studies were conducted in community mental health center settings, thus eliminating the need to transition services developed in academia into the “real world.” The next generation of NIMH studies will be primarily conducted in analogous settings under the Early Psychosis Intervention Network (EPINET).⁴⁰ EPINET’s study design echoes that responsible for the stepwise successes in the late 20th century that produced cures for the deadliest childhood cancer, acute lymphoblastic leukemia (ALL). This disease was successfully treated by modifying diverse evidence-based practices without relying on pharmacologic or other major treatment breakthroughs. Despite this, the effort yielded successful personalized interventions that were not obtainable for other severe childhood conditions.⁴⁰ EPINET hopes to automate much of these stepwise advances with a learning health system. This program relies on data routinely collected in clinical practice to drive the process of scientific discovery. Specifically, it determines the relationships between clinical features, biologic measures, treatment characteristics, and symptomatic and functional outcomes. EPINET aims to accelerate our understanding of biomarkers of psychosis risk and onset, as well as factors associated with recovery and cure. Dashboard displays of outcomes will allow for real-time comparisons within and across early intervention clinics. This in turn identifies performance gaps and drives continuous quality improvement.

Continue to: Barriers to optimizing program efficacy for both models

Unfortunately, there are stark differences between ALL and severe mental disorders that potentially jeopardize the achievement of these aims, despite the advances in data analytic abilities that drive the learning health system. Specifically, the heterogeneity of psychotic illnesses and the absence of reliable prognostic and modifiable risk markers (responsible for failed efforts to enhance treatment of serious mental illness over the last half century^1,2,41) are unlikely to be resolved by a learning health system. These measures are vital to determine whether specific interventions are effective, particularly given the absence of a randomized control group in the EPINET/learning health system design. Fortunately, however, the National Institutes for Health has recently initiated the Accelerating Medicines Partnership–Schizophrenia (AMP-SCZ). This approach seeks “promising biological markers that can help identify those at risk of developing schizophrenia as early as possible, track the progression of symptoms and other outcomes and ultimately define targets for treatment development.”⁴² The Box^{1,4,9,10,36,41,43-45} describes some of the challenges involved in identifying biomarkers of severe mental illness.

Box

A strength-based approach

The absence of sufficiently powered RCTs for prevention studies and the reliance on intermediate outcomes for FEP studies leaves unanswered whether such programs can effectively prevent chronic psychosis at a cost society is willing to pay. Still, substantial evidence indicates that outreach, long-acting injectable antipsychotics, early consideration of clozapine, family therapy, CBT for psychosis/attenuated psychosis, and services focused on competitive employment can preserve social and occupational functioning.^16,34 Until these broader questions are more definitively addressed, it seems reasonable to apply what we have learned (Table^{11,12,35,37-39,46}).

CP02010012_t1.PNG

Simply avoiding the most divisive aspects of the medical model that inadvertently promote stigma and undercut self-confidence may help maintain patients’ willingness to learn how best to apply their strengths and manage their limitations.¹¹ The progression to enduring psychotic features (eg, fixed delusions) may reflect ongoing social isolation and alienation. A strength-based approach seeks first to establish common goals (eg, school, work, friends, family support, housing, leaving home) and then works to empower the patient to successfully reach those goals.³⁵ This typically involves giving them the opportunity to fail, avoiding criticism when they do, and focusing on these experiences as learning opportunities from which success can ultimately result.

It is difficult to offer all these services in a typical private practice setting. Instead, it may make more sense to use one of the hundreds of early intervention services programs in the United States.⁴⁶ If a psychiatric clinician is dedicated to working with this population, it may also be possible to establish ongoing relationships with primary care physicians, family and CBT therapists, family support services (eg, National Alliance on Mental Illness), caseworkers and employment counselors. In essence, a psychiatrist may be able re-create a multidisciplinary effort by taking advantage of the expertise of these various professionals. The challenge is to create a consistent message for patients and families in the absence of regular meetings with the clinical team, although the recent reliance on and improved sophistication of virtual meetings may help. Psychiatrists often play a critical role even when the patient is not prescribed medication, partly because they are most comfortable handling the risks and may have the most comprehensive understanding of the issues at play. When medications are appropriate and patients with FEP are willing to take them, early consideration of long-acting injectable antipsychotics and clozapine may provide better stabilization and diminish the risk of earlier and more frequent relapses.

Bottom Line

Early interventions for psychosis include the prevention model and the first-episode recovery model. It is difficult to assess, compare, and optimize the effectiveness of such programs. Current evidence supports a ‘strength-based’ approach focused on finding common ground between patients, their support system, and the treatment team.

Related Resources

• Early Assessment and Support Alliance. National Early Psychosis Directory. https://easacommunity.org/nationaldirectory.php
• Kane JM, Robinson DG, Schooler NR, et al. Comprehensive versus usual community care for first-episode psychosis: 2-year outcomes from the NIMH RAISE Early Treatment Program. Am J Psychiatry. 2016 ;173(4):362-372

Drug Brand Name

Clozapine • Clozaril

Neuroscience research over the past half century has failed to significantly advance the treatment of severe mental illness.^1,2 Hence, evidence that a longer duration of untreated psychosis (DUP) aggravates—and early intervention with medication and social supports ameliorates—the long-term adverse consequences of psychotic disorders generated a great deal of interest.^3,4 This knowledge led to the development of diverse early intervention services worldwide aimed at this putative “critical window.” It raised the possibility that appropriate interventions could prevent the long-term disability that makes chronic psychosis one of the most debilitating disorders.^5,6 However, even beyond the varied cultural and economic confounds, it is difficult to assess, compare, and optimize program effectiveness.⁷ Obstacles include paucity of sufficiently powered, well-designed randomized controlled trials (RCTs), the absence of diagnostic biomarkers or other prognostic indicators to better account for the inherent heterogeneity in the population and associated outcomes, and the absence of modifiable risk factors that can guide interventions and provide intermediate outcomes.^4,8-10

To better appreciate these issues, it is important to distinguish whether a program is designed to prevent psychosis, or to mitigate the effects of psychosis. Two models include the:

• Prevention model, which focuses on young individuals who are not yet overtly psychotic but at high risk
• First-episode recovery model, which focuses on those who have experienced a first episode of psychosis (FEP) but have not yet developed a chronic disorder.

Both models share long-term goals and are hampered by many of the same issues summarized above. They both deviate markedly from the standard medical model by including psychosocial services designed to promote restoration of a self-defined trajectory to greater independence.^11-14 The 2 differ, however, in the challenges they must overcome to produce their sample populations and establish effective interventions.^10,15,16

In this article, we provide a succinct overview of these issues and a set of recommendations based on a “strength-based” approach. This approach focuses on finding common ground between patients, their support system, and the treatment team in the service of empowering patients to resume responsibility for transition to adulthood.

The prevention model

While most prevention initiatives in medicine rely on the growing ability to target specific pathophysiologic pathways,³ preventing psychosis relies on clinical evidence showing that DUP and early interventions predict a better course of severe mental illness.¹⁷ In contrast, initiatives such as normalizing neonatal neuronal pathways are more consistent with the strategy utilized in other fields but have yet to yield a pathophysiologic target for psychosis.^3,18

Initial efforts to identify ‘at-risk’ individuals

The prevention model of psychosis is based on the ability to identify young individuals at high risk for developing a psychotic disorder (Figure). The first screening measures were focused on prodromal psychosis (eg, significant loss of function, family history, and “intermittent” and “attenuated” psychotic symptoms). When applied to referred (ie, pre-screened) samples, 30% to 40% of this group who met criteria transitioned to psychosis over the next 1 to 3 years despite antidepressant and psychosocial interventions.¹⁹ Comprising 8 academic medical centers, the North American Prodrome Longitudinal Study (NAPLS) produced similar results using the Structured Interview for Prodromal Syndromes (SIPS).¹⁷ Thus, 30% to 50% of pre-screened individuals referred by school counselors and mental health professionals met SIPS criteria, and 35% of these individuals transitioned to psychosis over 30 months. The validity of this measure was further supported by the fact that higher baseline levels of unusual thought content, suspicion/paranoia, social impairment, and substance abuse successfully distinguished approximately 80% of those who transitioned to psychosis. The results of this first generation of screening studies were exciting because they seemed to demonstrate that highly concentrated samples of young persons at high risk of developing psychosis could be identified, and that fine-tuning the screening criteria could produce even more enriched samples (ie, positive predictive power).

CP02010012_f1.PNG

Initial interventions produced promising results

The development of effective screening measures led to reports of effective treatment interventions. These were largely applied in a clinical staging model that restricted antipsychotic medications to those who failed to improve after receiving potentially “less toxic” interventions (eg, omega-3 polyunsaturated fatty acids and other antioxidants; psychotherapy; cognitive-behavioral therapy [CBT]; family therapy).⁵ While study designs were typically quasi-experimental, the interventions appeared to dramatically diminish the transition to psychosis (ie, approximately 50%).

Continue to: The first generation...

The first generation of RCTs appeared to confirm these results, although sample sizes were small, and most study designs assessed only a single intervention. Initial meta-analyses of these data reported that both CBT and antipsychotics appeared to prevent approximately one-half of individuals from becoming psychotic at 12 months, and more than one-third at 2 to 4 years, compared with treatment as usual.²⁰

While some researchers challenged the validity of these findings,^21-23 the results generated tremendous international enthusiasm and calls for widespread implementation.⁶ The number of early intervention services (EIS) centers increased dramatically worldwide, and in 2014 the National Institute for Health and Care Excellence released standards for interventions to prevent transition to psychosis.²⁴ These included close monitoring, CBT and family interventions, and avoiding antipsychotics when possible.²⁴

Focusing on sensitivity over specificity

The first generation of studies generated by the prevention model relied on outreach programs or referrals, which produced small samples of carefully selected, pre-screened individuals (Figure, Pre-screened) who were then screened again to establish the high-risk sample.²⁵ While approximately 33% of these individuals became psychotic, the screening process required a very efficient means of eliminating those not at high-risk (given the ultimate target population represented only approximately .5% of young people) (Figure). The pre-screening and screening processes in these first-generation studies were labor-intensive but could only identify approximately 5% of those individuals destined to become psychotic over the next 2 or 3 years. Thus, alternative methods to enhance sensitivity were needed to extend programming to the general population.

Second-generation pre-screening (Figure; Step 1). New pre-screening methods were identified that captured more individuals destined to become psychotic. For example, approximately 90% of this population were registered in health care organizations (eg, health maintenance organizations) and received a psychiatric diagnosis in the year prior to the onset of psychosis (true positives).⁸ These samples, however, contained a much higher percentage of persons not destined to become psychotic, and somehow the issue of specificity (decreasing false positives) was minimized.^8,9 For example, pre-screened samples contained 20 to 50 individuals not destined to become psychotic for each one who did.²⁶ Since screening measures could only eliminate approximately 20% of this group (Figure, Step 2, page 25), second-generation transition rates fell from 30% to 40% to 2% to 10%.^27,28

Other pre-screening approaches were introduced, but they also focused on capturing more of those destined to become psychotic (sensitivity) than eliminating those who would not (specificity). For instance, Australia opened more than 100 “Headspace” community centers nationwide designed to promote engagement and self-esteem in youth experiencing anxiety; depression; stress; relationship, work, or school problems; or bullying.¹³ Most services were free and included mental health staff who screened for psychosis and provided a wide range of services in a destigmatized setting. These methods identified at least an additional 5% to 7% of individuals destined to become psychotic, but to our knowledge, no data have been published on whether they helped eliminate those who did not.

Continue to: Second-generation screening

Second-generation screening (Figure, Step 2). A second screening aims to retain those pre-screened individuals who will become psychotic (ie, minimizing false negatives) while further minimizing those who do not (ie, minimizing false positives). The addition of cognitive, neural (eg, structural MRI; neurophysiologic), and biochemical (eg, inflammatory immune and stress) markers to the risk calculators have produced a sensitivity close to 100%.^8,9 Unfortunately, these studies downplayed specificity, which remained approximately 20%.^8,9 Specificity is critical not just because of concerns about stigma (ie, labeling people as pre-psychotic when they are not) but also because of the adverse effects of antipsychotic medications and the effects on future program development (interventions are costly and labor-intensive). Also, diluting the pool with individuals not at risk makes it nearly impossible to identify effective interventions (ie, power).^27,28

While some studies focused on increasing specificity (to approximately 75%), this leads to an unacceptable loss of sensitivity (from 90% to 60%),²⁹ with 40% of pre-screened individuals who would become psychotic being eliminated from the study population. The addition of other biological markers (eg, salivary cortisol)³⁰ and use of learning health systems may be able to enhance these numbers (initial reports of specificity = 87% and sensitivity = 85%).^8,9 This is accomplished by integrating artificial and human intelligence measures of clinical (symptom and neurocognitive measures) and biological (eg, polygenetic risk scores; gray matter volume) variables.³¹ However, even if these results are replicated, more effective pre-screening measures will be required.

Identifying a suitable sample population for prevention program studies is clearly more complicated than for FEP studies, where one can usually identify many of those in the at-risk population by their first hospitalization for psychotic symptoms. The issues of false positives (eg, substance-induced psychosis) and negatives (eg, slow deterioration, prominent negative symptoms) are important concerns, but proportionately far less significant.

Prevention and FEP interventions

Once a study sample is constituted, 1 to 3 years of treatment interventions are initiated. Interventions for prevention programs typically include CBT directed at attenuated psychosis (eg, reframing or de-catastrophizing unusual thoughts and minimizing distress associated with unusual perceptions); case management to facilitate personal, educational, and vocational goals; and family therapy in single or multi-group formats to educate one’s support system about the risk state and to minimize adverse familial responses.¹⁴ Many programs also include supported education or employment services to promote reintegration in age-appropriate activities; group therapy focused on substance abuse and social skills training; cognitive remediation to ameliorate the cognitive dysfunction; and an array of pharmacologic interventions designed to delay or prevent transition to psychosis or to alleviate symptoms. While most interventions are similar, FEP programs have recently included peer support staff. This appears to instill hope in newly diagnosed patients, provide role models, and provide peer supporters an opportunity to use their experiences to help others and earn income.³²

The breadth and depth of these services are critical because retention in the program is highly dependent on participant engagement, which in turn is highly dependent on whether the program can help individuals get what they want (eg, friends, employment, education, more autonomy, physical health). The setting and atmosphere of the treatment program and the willingness/ability of staff to meet participants in the community are also important elements.^11,12 In this context, the Headspace community centers are having an impact far beyond Australia and may prove to be a particularly good model.¹³

Continue to: Assessing prevention and FEP interventions

The second generation of studies of prevention programs has not confirmed, let alone extended, the earlier findings and meta-analyses. A 2020 report concluded CBT was still the most promising intervention; it was more effective than control treatments at 12 and 18 months, although not at 6, 24, or 48 months.³³ This review included controlled, open-label, and naturalistic studies that assessed family therapy; omega-3 polyunsaturated fatty acids; integrated psychological therapy (a package of interventions that included family education, CBT, social skills training, and cognitive remediation); N-methyl-D-aspartate receptor modulators; mood stabilizers; and antipsychotics. In addition to the evidence supporting CBT, the results also indicated nonsignificant trends favoring family and integrated psychological therapy. Neither a 2019 Cochrane review³⁴ nor a 2020 “umbrella” assessment of 42 meta-analyses⁹ found convincing evidence for the efficacy of any program components.

While these disappointing findings are at least partly attributable to the methodological challenges described above and in the Figure, other factors may hinder establishing effective interventions. In contrast to FEP studies, those focused on prevention had a very ambitious agenda (eliminating psychosis) and tended to downplay more modest intermediate outcomes. These studies also tended to assess new ideas with small samples rather than pursue promising findings with larger multi-site studies focused on a group of interventions. The authors of a Cochrane review observed “There is the impression that in this whole area there is a triumph of hope over adversity. There is the repeated hope invested in another—often unique—study question and then a study of fewer than 100 participants are completed. This results in the set of comparisons reported here, all 9 of which are too underpowered to really highlight clear differences.”³⁴ To use a baseball analogy, it seems that investigators are “swinging for the fence” when a few singles are what’s really needed.

From the outset, the goals of FEP studies were more modest, largely ignoring the task of developing consensus definitions of recovery that require following patients for up to 5 to 10 years. Instead, they use intermediate endpoints based on adapting treatments that already appeared effective in patients with chronic mental disorders.³⁵ As a consequence, researchers examining FEP demonstrated clear, albeit limited, salutary effects using large multi-site trials and previously established outcome measures.^3,10,36 For instance, the Recovery After an Initial Schizophrenia Episode-Early Treatment Program (RAISE-ETP) study was a 2-year, multi-site RCT (N = 404) funded by the National Institute of Mental Health (NIMH). The investigators reported improved indices of social function (eg, quality of life; education and work participation) and total ratings of psychopathology and depression compared with treatment as usual. Furthermore, they established that DUP predicted treatment response.³⁵ The latter finding was underscored by improvement being limited to the 50% with <74 weeks DUP. Annual costs of the program per 1 standard deviation improvement in quality of life were approximately $1,000 for patients with <74 weeks DUP and $40,000 for those with >74 weeks DUP. Concurrent meta-analyses confirmed and extended these findings,¹⁶ showing higher remission rates; diminished relapses and hospital admissions; greater engagement in programming; greater involvement in work and school; improved quality of life; and other steps toward recovery. These studies were also able to establish a clear benefit of antipsychotic medications, particularly a high acceptance of long-acting injectable antipsychotic formulations, which promoted adherence and decreased some adverse events³⁷; and early use of clozapine therapy, which improved remission rates and longer-term outcomes.³⁸ Other findings underscored the need to anticipate and address new problems associated with effective antipsychotic therapy (eg, antipsychotic response correlates with weight gain, a particularly intolerable adverse event for this age group).³⁹ Providing pre-emptive strategies such as exercise groups and nutritional education may be necessary to maintain adherence.

Limitations of FEP studies

The effect sizes in these FEP studies were small to medium on outcome measures tracking recovery and associated indicators (eg, global functioning, school/work participation, treatment engagement); the number needed to treat for each of these was >10. There is no clear evidence that recovery programs such as RAISE-ETP actually reduce longer-term disability. Most studies showed disability payments increased while clinical benefits tended to fade over time. In addition, by grouping interventions together, the studies made it difficult to identify effective vs ineffective treatments, let alone determine how best to personalize therapy for participants in future studies.

The next generation of FEP studies

While limited in scope, the results of the recent FEP studies justify a next generation of recovery interventions designed to address these shortcomings and optimize program outcomes.³⁹ Most previous FEP studies were conducted in community mental health center settings, thus eliminating the need to transition services developed in academia into the “real world.” The next generation of NIMH studies will be primarily conducted in analogous settings under the Early Psychosis Intervention Network (EPINET).⁴⁰ EPINET’s study design echoes that responsible for the stepwise successes in the late 20th century that produced cures for the deadliest childhood cancer, acute lymphoblastic leukemia (ALL). This disease was successfully treated by modifying diverse evidence-based practices without relying on pharmacologic or other major treatment breakthroughs. Despite this, the effort yielded successful personalized interventions that were not obtainable for other severe childhood conditions.⁴⁰ EPINET hopes to automate much of these stepwise advances with a learning health system. This program relies on data routinely collected in clinical practice to drive the process of scientific discovery. Specifically, it determines the relationships between clinical features, biologic measures, treatment characteristics, and symptomatic and functional outcomes. EPINET aims to accelerate our understanding of biomarkers of psychosis risk and onset, as well as factors associated with recovery and cure. Dashboard displays of outcomes will allow for real-time comparisons within and across early intervention clinics. This in turn identifies performance gaps and drives continuous quality improvement.

Continue to: Barriers to optimizing program efficacy for both models

Unfortunately, there are stark differences between ALL and severe mental disorders that potentially jeopardize the achievement of these aims, despite the advances in data analytic abilities that drive the learning health system. Specifically, the heterogeneity of psychotic illnesses and the absence of reliable prognostic and modifiable risk markers (responsible for failed efforts to enhance treatment of serious mental illness over the last half century^1,2,41) are unlikely to be resolved by a learning health system. These measures are vital to determine whether specific interventions are effective, particularly given the absence of a randomized control group in the EPINET/learning health system design. Fortunately, however, the National Institutes for Health has recently initiated the Accelerating Medicines Partnership–Schizophrenia (AMP-SCZ). This approach seeks “promising biological markers that can help identify those at risk of developing schizophrenia as early as possible, track the progression of symptoms and other outcomes and ultimately define targets for treatment development.”⁴² The Box^{1,4,9,10,36,41,43-45} describes some of the challenges involved in identifying biomarkers of severe mental illness.

Box

A strength-based approach

The absence of sufficiently powered RCTs for prevention studies and the reliance on intermediate outcomes for FEP studies leaves unanswered whether such programs can effectively prevent chronic psychosis at a cost society is willing to pay. Still, substantial evidence indicates that outreach, long-acting injectable antipsychotics, early consideration of clozapine, family therapy, CBT for psychosis/attenuated psychosis, and services focused on competitive employment can preserve social and occupational functioning.^16,34 Until these broader questions are more definitively addressed, it seems reasonable to apply what we have learned (Table^{11,12,35,37-39,46}).

CP02010012_t1.PNG

Simply avoiding the most divisive aspects of the medical model that inadvertently promote stigma and undercut self-confidence may help maintain patients’ willingness to learn how best to apply their strengths and manage their limitations.¹¹ The progression to enduring psychotic features (eg, fixed delusions) may reflect ongoing social isolation and alienation. A strength-based approach seeks first to establish common goals (eg, school, work, friends, family support, housing, leaving home) and then works to empower the patient to successfully reach those goals.³⁵ This typically involves giving them the opportunity to fail, avoiding criticism when they do, and focusing on these experiences as learning opportunities from which success can ultimately result.

It is difficult to offer all these services in a typical private practice setting. Instead, it may make more sense to use one of the hundreds of early intervention services programs in the United States.⁴⁶ If a psychiatric clinician is dedicated to working with this population, it may also be possible to establish ongoing relationships with primary care physicians, family and CBT therapists, family support services (eg, National Alliance on Mental Illness), caseworkers and employment counselors. In essence, a psychiatrist may be able re-create a multidisciplinary effort by taking advantage of the expertise of these various professionals. The challenge is to create a consistent message for patients and families in the absence of regular meetings with the clinical team, although the recent reliance on and improved sophistication of virtual meetings may help. Psychiatrists often play a critical role even when the patient is not prescribed medication, partly because they are most comfortable handling the risks and may have the most comprehensive understanding of the issues at play. When medications are appropriate and patients with FEP are willing to take them, early consideration of long-acting injectable antipsychotics and clozapine may provide better stabilization and diminish the risk of earlier and more frequent relapses.

Bottom Line

Early interventions for psychosis include the prevention model and the first-episode recovery model. It is difficult to assess, compare, and optimize the effectiveness of such programs. Current evidence supports a ‘strength-based’ approach focused on finding common ground between patients, their support system, and the treatment team.

Related Resources

• Early Assessment and Support Alliance. National Early Psychosis Directory. https://easacommunity.org/nationaldirectory.php
• Kane JM, Robinson DG, Schooler NR, et al. Comprehensive versus usual community care for first-episode psychosis: 2-year outcomes from the NIMH RAISE Early Treatment Program. Am J Psychiatry. 2016 ;173(4):362-372

Drug Brand Name

Clozapine • Clozaril

Neuroscience research over the past half century has failed to significantly advance the treatment of severe mental illness.^1,2 Hence, evidence that a longer duration of untreated psychosis (DUP) aggravates—and early intervention with medication and social supports ameliorates—the long-term adverse consequences of psychotic disorders generated a great deal of interest.^3,4 This knowledge led to the development of diverse early intervention services worldwide aimed at this putative “critical window.” It raised the possibility that appropriate interventions could prevent the long-term disability that makes chronic psychosis one of the most debilitating disorders.^5,6 However, even beyond the varied cultural and economic confounds, it is difficult to assess, compare, and optimize program effectiveness.⁷ Obstacles include paucity of sufficiently powered, well-designed randomized controlled trials (RCTs), the absence of diagnostic biomarkers or other prognostic indicators to better account for the inherent heterogeneity in the population and associated outcomes, and the absence of modifiable risk factors that can guide interventions and provide intermediate outcomes.^4,8-10

To better appreciate these issues, it is important to distinguish whether a program is designed to prevent psychosis, or to mitigate the effects of psychosis. Two models include the:

• Prevention model, which focuses on young individuals who are not yet overtly psychotic but at high risk
• First-episode recovery model, which focuses on those who have experienced a first episode of psychosis (FEP) but have not yet developed a chronic disorder.

Both models share long-term goals and are hampered by many of the same issues summarized above. They both deviate markedly from the standard medical model by including psychosocial services designed to promote restoration of a self-defined trajectory to greater independence.^11-14 The 2 differ, however, in the challenges they must overcome to produce their sample populations and establish effective interventions.^10,15,16

In this article, we provide a succinct overview of these issues and a set of recommendations based on a “strength-based” approach. This approach focuses on finding common ground between patients, their support system, and the treatment team in the service of empowering patients to resume responsibility for transition to adulthood.

The prevention model

While most prevention initiatives in medicine rely on the growing ability to target specific pathophysiologic pathways,³ preventing psychosis relies on clinical evidence showing that DUP and early interventions predict a better course of severe mental illness.¹⁷ In contrast, initiatives such as normalizing neonatal neuronal pathways are more consistent with the strategy utilized in other fields but have yet to yield a pathophysiologic target for psychosis.^3,18

Initial efforts to identify ‘at-risk’ individuals

The prevention model of psychosis is based on the ability to identify young individuals at high risk for developing a psychotic disorder (Figure). The first screening measures were focused on prodromal psychosis (eg, significant loss of function, family history, and “intermittent” and “attenuated” psychotic symptoms). When applied to referred (ie, pre-screened) samples, 30% to 40% of this group who met criteria transitioned to psychosis over the next 1 to 3 years despite antidepressant and psychosocial interventions.¹⁹ Comprising 8 academic medical centers, the North American Prodrome Longitudinal Study (NAPLS) produced similar results using the Structured Interview for Prodromal Syndromes (SIPS).¹⁷ Thus, 30% to 50% of pre-screened individuals referred by school counselors and mental health professionals met SIPS criteria, and 35% of these individuals transitioned to psychosis over 30 months. The validity of this measure was further supported by the fact that higher baseline levels of unusual thought content, suspicion/paranoia, social impairment, and substance abuse successfully distinguished approximately 80% of those who transitioned to psychosis. The results of this first generation of screening studies were exciting because they seemed to demonstrate that highly concentrated samples of young persons at high risk of developing psychosis could be identified, and that fine-tuning the screening criteria could produce even more enriched samples (ie, positive predictive power).

CP02010012_f1.PNG

Initial interventions produced promising results

The development of effective screening measures led to reports of effective treatment interventions. These were largely applied in a clinical staging model that restricted antipsychotic medications to those who failed to improve after receiving potentially “less toxic” interventions (eg, omega-3 polyunsaturated fatty acids and other antioxidants; psychotherapy; cognitive-behavioral therapy [CBT]; family therapy).⁵ While study designs were typically quasi-experimental, the interventions appeared to dramatically diminish the transition to psychosis (ie, approximately 50%).

Continue to: The first generation...

The first generation of RCTs appeared to confirm these results, although sample sizes were small, and most study designs assessed only a single intervention. Initial meta-analyses of these data reported that both CBT and antipsychotics appeared to prevent approximately one-half of individuals from becoming psychotic at 12 months, and more than one-third at 2 to 4 years, compared with treatment as usual.²⁰

While some researchers challenged the validity of these findings,^21-23 the results generated tremendous international enthusiasm and calls for widespread implementation.⁶ The number of early intervention services (EIS) centers increased dramatically worldwide, and in 2014 the National Institute for Health and Care Excellence released standards for interventions to prevent transition to psychosis.²⁴ These included close monitoring, CBT and family interventions, and avoiding antipsychotics when possible.²⁴

Focusing on sensitivity over specificity

The first generation of studies generated by the prevention model relied on outreach programs or referrals, which produced small samples of carefully selected, pre-screened individuals (Figure, Pre-screened) who were then screened again to establish the high-risk sample.²⁵ While approximately 33% of these individuals became psychotic, the screening process required a very efficient means of eliminating those not at high-risk (given the ultimate target population represented only approximately .5% of young people) (Figure). The pre-screening and screening processes in these first-generation studies were labor-intensive but could only identify approximately 5% of those individuals destined to become psychotic over the next 2 or 3 years. Thus, alternative methods to enhance sensitivity were needed to extend programming to the general population.

Second-generation pre-screening (Figure; Step 1). New pre-screening methods were identified that captured more individuals destined to become psychotic. For example, approximately 90% of this population were registered in health care organizations (eg, health maintenance organizations) and received a psychiatric diagnosis in the year prior to the onset of psychosis (true positives).⁸ These samples, however, contained a much higher percentage of persons not destined to become psychotic, and somehow the issue of specificity (decreasing false positives) was minimized.^8,9 For example, pre-screened samples contained 20 to 50 individuals not destined to become psychotic for each one who did.²⁶ Since screening measures could only eliminate approximately 20% of this group (Figure, Step 2, page 25), second-generation transition rates fell from 30% to 40% to 2% to 10%.^27,28

Other pre-screening approaches were introduced, but they also focused on capturing more of those destined to become psychotic (sensitivity) than eliminating those who would not (specificity). For instance, Australia opened more than 100 “Headspace” community centers nationwide designed to promote engagement and self-esteem in youth experiencing anxiety; depression; stress; relationship, work, or school problems; or bullying.¹³ Most services were free and included mental health staff who screened for psychosis and provided a wide range of services in a destigmatized setting. These methods identified at least an additional 5% to 7% of individuals destined to become psychotic, but to our knowledge, no data have been published on whether they helped eliminate those who did not.

Continue to: Second-generation screening

Second-generation screening (Figure, Step 2). A second screening aims to retain those pre-screened individuals who will become psychotic (ie, minimizing false negatives) while further minimizing those who do not (ie, minimizing false positives). The addition of cognitive, neural (eg, structural MRI; neurophysiologic), and biochemical (eg, inflammatory immune and stress) markers to the risk calculators have produced a sensitivity close to 100%.^8,9 Unfortunately, these studies downplayed specificity, which remained approximately 20%.^8,9 Specificity is critical not just because of concerns about stigma (ie, labeling people as pre-psychotic when they are not) but also because of the adverse effects of antipsychotic medications and the effects on future program development (interventions are costly and labor-intensive). Also, diluting the pool with individuals not at risk makes it nearly impossible to identify effective interventions (ie, power).^27,28

While some studies focused on increasing specificity (to approximately 75%), this leads to an unacceptable loss of sensitivity (from 90% to 60%),²⁹ with 40% of pre-screened individuals who would become psychotic being eliminated from the study population. The addition of other biological markers (eg, salivary cortisol)³⁰ and use of learning health systems may be able to enhance these numbers (initial reports of specificity = 87% and sensitivity = 85%).^8,9 This is accomplished by integrating artificial and human intelligence measures of clinical (symptom and neurocognitive measures) and biological (eg, polygenetic risk scores; gray matter volume) variables.³¹ However, even if these results are replicated, more effective pre-screening measures will be required.

Identifying a suitable sample population for prevention program studies is clearly more complicated than for FEP studies, where one can usually identify many of those in the at-risk population by their first hospitalization for psychotic symptoms. The issues of false positives (eg, substance-induced psychosis) and negatives (eg, slow deterioration, prominent negative symptoms) are important concerns, but proportionately far less significant.

Prevention and FEP interventions

Once a study sample is constituted, 1 to 3 years of treatment interventions are initiated. Interventions for prevention programs typically include CBT directed at attenuated psychosis (eg, reframing or de-catastrophizing unusual thoughts and minimizing distress associated with unusual perceptions); case management to facilitate personal, educational, and vocational goals; and family therapy in single or multi-group formats to educate one’s support system about the risk state and to minimize adverse familial responses.¹⁴ Many programs also include supported education or employment services to promote reintegration in age-appropriate activities; group therapy focused on substance abuse and social skills training; cognitive remediation to ameliorate the cognitive dysfunction; and an array of pharmacologic interventions designed to delay or prevent transition to psychosis or to alleviate symptoms. While most interventions are similar, FEP programs have recently included peer support staff. This appears to instill hope in newly diagnosed patients, provide role models, and provide peer supporters an opportunity to use their experiences to help others and earn income.³²

The breadth and depth of these services are critical because retention in the program is highly dependent on participant engagement, which in turn is highly dependent on whether the program can help individuals get what they want (eg, friends, employment, education, more autonomy, physical health). The setting and atmosphere of the treatment program and the willingness/ability of staff to meet participants in the community are also important elements.^11,12 In this context, the Headspace community centers are having an impact far beyond Australia and may prove to be a particularly good model.¹³

Continue to: Assessing prevention and FEP interventions

The second generation of studies of prevention programs has not confirmed, let alone extended, the earlier findings and meta-analyses. A 2020 report concluded CBT was still the most promising intervention; it was more effective than control treatments at 12 and 18 months, although not at 6, 24, or 48 months.³³ This review included controlled, open-label, and naturalistic studies that assessed family therapy; omega-3 polyunsaturated fatty acids; integrated psychological therapy (a package of interventions that included family education, CBT, social skills training, and cognitive remediation); N-methyl-D-aspartate receptor modulators; mood stabilizers; and antipsychotics. In addition to the evidence supporting CBT, the results also indicated nonsignificant trends favoring family and integrated psychological therapy. Neither a 2019 Cochrane review³⁴ nor a 2020 “umbrella” assessment of 42 meta-analyses⁹ found convincing evidence for the efficacy of any program components.

While these disappointing findings are at least partly attributable to the methodological challenges described above and in the Figure, other factors may hinder establishing effective interventions. In contrast to FEP studies, those focused on prevention had a very ambitious agenda (eliminating psychosis) and tended to downplay more modest intermediate outcomes. These studies also tended to assess new ideas with small samples rather than pursue promising findings with larger multi-site studies focused on a group of interventions. The authors of a Cochrane review observed “There is the impression that in this whole area there is a triumph of hope over adversity. There is the repeated hope invested in another—often unique—study question and then a study of fewer than 100 participants are completed. This results in the set of comparisons reported here, all 9 of which are too underpowered to really highlight clear differences.”³⁴ To use a baseball analogy, it seems that investigators are “swinging for the fence” when a few singles are what’s really needed.

From the outset, the goals of FEP studies were more modest, largely ignoring the task of developing consensus definitions of recovery that require following patients for up to 5 to 10 years. Instead, they use intermediate endpoints based on adapting treatments that already appeared effective in patients with chronic mental disorders.³⁵ As a consequence, researchers examining FEP demonstrated clear, albeit limited, salutary effects using large multi-site trials and previously established outcome measures.^3,10,36 For instance, the Recovery After an Initial Schizophrenia Episode-Early Treatment Program (RAISE-ETP) study was a 2-year, multi-site RCT (N = 404) funded by the National Institute of Mental Health (NIMH). The investigators reported improved indices of social function (eg, quality of life; education and work participation) and total ratings of psychopathology and depression compared with treatment as usual. Furthermore, they established that DUP predicted treatment response.³⁵ The latter finding was underscored by improvement being limited to the 50% with <74 weeks DUP. Annual costs of the program per 1 standard deviation improvement in quality of life were approximately $1,000 for patients with <74 weeks DUP and $40,000 for those with >74 weeks DUP. Concurrent meta-analyses confirmed and extended these findings,¹⁶ showing higher remission rates; diminished relapses and hospital admissions; greater engagement in programming; greater involvement in work and school; improved quality of life; and other steps toward recovery. These studies were also able to establish a clear benefit of antipsychotic medications, particularly a high acceptance of long-acting injectable antipsychotic formulations, which promoted adherence and decreased some adverse events³⁷; and early use of clozapine therapy, which improved remission rates and longer-term outcomes.³⁸ Other findings underscored the need to anticipate and address new problems associated with effective antipsychotic therapy (eg, antipsychotic response correlates with weight gain, a particularly intolerable adverse event for this age group).³⁹ Providing pre-emptive strategies such as exercise groups and nutritional education may be necessary to maintain adherence.

Limitations of FEP studies

The effect sizes in these FEP studies were small to medium on outcome measures tracking recovery and associated indicators (eg, global functioning, school/work participation, treatment engagement); the number needed to treat for each of these was >10. There is no clear evidence that recovery programs such as RAISE-ETP actually reduce longer-term disability. Most studies showed disability payments increased while clinical benefits tended to fade over time. In addition, by grouping interventions together, the studies made it difficult to identify effective vs ineffective treatments, let alone determine how best to personalize therapy for participants in future studies.

The next generation of FEP studies

While limited in scope, the results of the recent FEP studies justify a next generation of recovery interventions designed to address these shortcomings and optimize program outcomes.³⁹ Most previous FEP studies were conducted in community mental health center settings, thus eliminating the need to transition services developed in academia into the “real world.” The next generation of NIMH studies will be primarily conducted in analogous settings under the Early Psychosis Intervention Network (EPINET).⁴⁰ EPINET’s study design echoes that responsible for the stepwise successes in the late 20th century that produced cures for the deadliest childhood cancer, acute lymphoblastic leukemia (ALL). This disease was successfully treated by modifying diverse evidence-based practices without relying on pharmacologic or other major treatment breakthroughs. Despite this, the effort yielded successful personalized interventions that were not obtainable for other severe childhood conditions.⁴⁰ EPINET hopes to automate much of these stepwise advances with a learning health system. This program relies on data routinely collected in clinical practice to drive the process of scientific discovery. Specifically, it determines the relationships between clinical features, biologic measures, treatment characteristics, and symptomatic and functional outcomes. EPINET aims to accelerate our understanding of biomarkers of psychosis risk and onset, as well as factors associated with recovery and cure. Dashboard displays of outcomes will allow for real-time comparisons within and across early intervention clinics. This in turn identifies performance gaps and drives continuous quality improvement.

Continue to: Barriers to optimizing program efficacy for both models

Unfortunately, there are stark differences between ALL and severe mental disorders that potentially jeopardize the achievement of these aims, despite the advances in data analytic abilities that drive the learning health system. Specifically, the heterogeneity of psychotic illnesses and the absence of reliable prognostic and modifiable risk markers (responsible for failed efforts to enhance treatment of serious mental illness over the last half century^1,2,41) are unlikely to be resolved by a learning health system. These measures are vital to determine whether specific interventions are effective, particularly given the absence of a randomized control group in the EPINET/learning health system design. Fortunately, however, the National Institutes for Health has recently initiated the Accelerating Medicines Partnership–Schizophrenia (AMP-SCZ). This approach seeks “promising biological markers that can help identify those at risk of developing schizophrenia as early as possible, track the progression of symptoms and other outcomes and ultimately define targets for treatment development.”⁴² The Box^{1,4,9,10,36,41,43-45} describes some of the challenges involved in identifying biomarkers of severe mental illness.

Box

A strength-based approach

The absence of sufficiently powered RCTs for prevention studies and the reliance on intermediate outcomes for FEP studies leaves unanswered whether such programs can effectively prevent chronic psychosis at a cost society is willing to pay. Still, substantial evidence indicates that outreach, long-acting injectable antipsychotics, early consideration of clozapine, family therapy, CBT for psychosis/attenuated psychosis, and services focused on competitive employment can preserve social and occupational functioning.^16,34 Until these broader questions are more definitively addressed, it seems reasonable to apply what we have learned (Table^{11,12,35,37-39,46}).

CP02010012_t1.PNG

Simply avoiding the most divisive aspects of the medical model that inadvertently promote stigma and undercut self-confidence may help maintain patients’ willingness to learn how best to apply their strengths and manage their limitations.¹¹ The progression to enduring psychotic features (eg, fixed delusions) may reflect ongoing social isolation and alienation. A strength-based approach seeks first to establish common goals (eg, school, work, friends, family support, housing, leaving home) and then works to empower the patient to successfully reach those goals.³⁵ This typically involves giving them the opportunity to fail, avoiding criticism when they do, and focusing on these experiences as learning opportunities from which success can ultimately result.

It is difficult to offer all these services in a typical private practice setting. Instead, it may make more sense to use one of the hundreds of early intervention services programs in the United States.⁴⁶ If a psychiatric clinician is dedicated to working with this population, it may also be possible to establish ongoing relationships with primary care physicians, family and CBT therapists, family support services (eg, National Alliance on Mental Illness), caseworkers and employment counselors. In essence, a psychiatrist may be able re-create a multidisciplinary effort by taking advantage of the expertise of these various professionals. The challenge is to create a consistent message for patients and families in the absence of regular meetings with the clinical team, although the recent reliance on and improved sophistication of virtual meetings may help. Psychiatrists often play a critical role even when the patient is not prescribed medication, partly because they are most comfortable handling the risks and may have the most comprehensive understanding of the issues at play. When medications are appropriate and patients with FEP are willing to take them, early consideration of long-acting injectable antipsychotics and clozapine may provide better stabilization and diminish the risk of earlier and more frequent relapses.

Bottom Line

Early interventions for psychosis include the prevention model and the first-episode recovery model. It is difficult to assess, compare, and optimize the effectiveness of such programs. Current evidence supports a ‘strength-based’ approach focused on finding common ground between patients, their support system, and the treatment team.

Related Resources

• Early Assessment and Support Alliance. National Early Psychosis Directory. https://easacommunity.org/nationaldirectory.php
• Kane JM, Robinson DG, Schooler NR, et al. Comprehensive versus usual community care for first-episode psychosis: 2-year outcomes from the NIMH RAISE Early Treatment Program. Am J Psychiatry. 2016 ;173(4):362-372

Drug Brand Name

Clozapine • Clozaril

When patients with major depressive disorder (MDD) do not achieve optimal outcomes after FDA-approved first-line treatments and standard adjunctive strategies, clinicians look for additional approaches to alleviate their patients’ symptoms. Recent research suggests that several “nontraditional” treatments used primarily as adjuncts to standard antidepressants have promise for treatment-resistant depression.

In Part 1 of this article (Current Psychiatry, September 2021), we examined off-label medications. In Part 2, we will review other nontraditional approaches to treatment-resistant depression, including herbal/nutraceutical agents, anti-inflammatory/immune system therapies, device-based treatments, and other alternative approaches. Importantly, some treatments also demonstrate adverse effects (Table^1-32). With a careful consideration of the risk/benefit balance, this article reviews some of the better-studied nontraditional treatment options for patients with treatment-resistant depression.

CP02010032_t1.PNG

Herbal/nutraceutical agents

This category encompasses a variety of commonly available “natural” options patients often ask about and at times self-prescribe. Examples evaluated in clinical trials include:

• vitamin D
• essential fatty acids (omega-3, omega-6)
• S-adenosyl-L-methionine (SAMe)
• hypericum perforatum (St. John’s Wort)
• probiotics.

Vitamin D deficiency has been linked to depression, possibly by lowering serotonin, norepinephrine, and dopamine concentrations.^1-3

A meta-analysis of 3 prospective, observational studies (N = 8,815) found an elevated risk of affective disorders in patients with low vitamin D levels.⁴ In addition, a systematic review and meta-analysis supported a potential role for vitamin D supplementation for patients with treatment-resistant depresssion.⁵

Toxicity can occur at levels >100 ng/mL, and resulting adverse effects may include weakness, fatigue, sleepiness, headache, loss of appetite, dry mouth, metallic taste, nausea, and vomiting. This vitamin can be considered as an adjunct to standard antidepressants, particularly in patients with treatment-resistant depression who have low vitamin D levels, but regular monitoring is necessary to avoid toxicity.

Essential fatty acids. Protein receptors embedded in lipid membranes and their binding affinities are influenced by omega-3 and omega-6 polyunsaturated fatty acids. Thus, essential fatty acids may benefit depression by maintaining membrane integrity and fluidity, as well as via their anti-inflammatory activity.

Continue to: Although results from...

Although results from controlled trials are mixed, a systematic review and meta-analysis of adjunctive nutraceuticals supported a potential role for essential fatty acids, primarily eicosapentaenoic acid (EPA), by itself or in combination with docosahexaenoic acid (DHA), with total EPA >60%.⁵ A second meta-analysis of 26 studies (N = 2,160) that considered only essential fatty acids concluded that EPA ≥60% at ≤1 g/d could benefit depression.⁶ Furthermore, omega-3 fatty acids may be helpful as an add-on agent for postpartum depression.⁷

Be aware that a diet rich in omega-6 greatly increases oxidized low-density lipoprotein levels in adipose tissue, potentially posing a cardiac risk factor. Clinicians need to be aware that self-prescribed use of essential fatty acids is common, and to ask about and monitor their patients’ use of these agents.

S-adenosyl-L-methionine (SAMe) is an intracellular amino acid and methyl donor. Among other actions, it is involved in the biosynthesis of hormones and neurotransmitters. There is promising but limited preliminary evidence of its efficacy and safety as a monotherapy or for antidepressant augmentation.⁸ For example, when compared with placebo for depressive symptoms in 19 randomized controlled trials (RCTs) (N = 878) ⁸:

• Five out of 6 earlier controlled studies reported SAMe IV (200 to 400 mg/d) or IM (45 to 50 mg/d) was more effective than placebo
• When the above studies were added to 14 subsequent studies for a meta-analysis, 12 of 19 RCTs reported that parenteral or oral SAMe was significantly more effective than placebo for depression (P < .05).

Overall, the safety and tolerability of SAMe are good. Common adverse effects include nausea, mild insomnia, dizziness, irritability, and anxiety. This is another compound widely available without a prescription and at times self-prescribed. It carries an acceptable risk/benefit balance, with decades of experience.

Hypericum perforatum (St. John’s Wort) is widely prescribed for depression in China and Europe, typically in doses ranging from 500 to 900 mg/d. Its mechanism of action in depression may relate to inhibition of serotonin, dopamine, and norepinephrine uptake from the synaptic cleft of these interconnecting neurotransmitter systems.

Continue to: A meta-analysis of 7 clinical trials...

A meta-analysis of 7 clinical trials (N = 3,808) comparing St. John’s Wort with various selective serotonin reuptake inhibitors (SSRIs) reported comparable rates of response (pooled relative risk .983, 95% CI .924 to 1.042; P < .001) and remission (pooled relative risk 1.013, 95% CI .892 to 1.134; P < .001).⁹ Further, there were significantly lower discontinuation/dropout rates (pooled odds ratio .587, 95% CI .478 to 0.697; P < .001) for St. John’s Wort compared with the SSRIs.

Existing evidence on the long-term efficacy and safety is limited (studies ranged from 4 to 12 weeks), as is evidence for patients with more severe depression or high suicidality.

Serious drug interactions include the potential for serotonin syndrome when St. John’s Wort is combined with certain antidepressants, compromised efficacy of benzodiazepines and standard antidepressants, and severe skin reactions to sun exposure. In addition, St. John’s Wort may not be safe to use during pregnancy or while breastfeeding. Because potential drug interactions can be serious and individuals often self-prescribe this agent, it is important to ask patients about their use of St. John’s Wort, and to be vigilant for such potential adverse interactions.

Probiotics. These agents produce neuroactive substances that act on the brain/gut axis. Preliminary evidence suggests that these “psychobiotics” confer mental health benefits.^10-12 Relative to other approaches, their low-risk profile make them an attractive option for some patients.

Anti-inflammatory/immune system therapies

Inflammation is linked to various medical and brain disorders. For example, patients with depression often demonstrate increased levels of peripheral blood inflammatory biomarkers (such as C-reactive protein and interleukin-6 and -17) that are known to alter norepinephrine, neuroendocrine (eg, the hypothalamic-pituitary-adrenal axis), and microglia function in addition to neuro­plasticity. Thus, targeting inflammation may facilitate the development of novel antidepressants. In addition, these agents may benefit depression associated with comorbid autoimmune disorders, such as psoriasis or rheumatoid arthritis. A systematic review and meta-analysis of 36 RCTs (N = 10,000) found 5 out of 6 anti-inflammatory agents improved depression.^13,14 In general, reported disadvantages of anti-inflammatories/immunosuppressants include the potential to block the antidepressant effect of some agents, the risk of opportunistic infections, and an increased risk of suicide.

Continue to: Statins

In a meta-analysis of 3 randomized, double-blind trials, 3 statins (lovastatin, atorvastatin, and simvastatin) significantly improved depression scores when used as an adjunctive therapy to fluoxetine and citalopram, compared with adjunctive placebo (N = 165, P < .001).¹⁵

Specific adverse effects of statins include headaches, muscle pain (rarely rhabdomyolysis), dizziness, rash, and liver damage. Statins also have the potential for adverse interactions with other medications. Given the limited efficacy literature on statins for depression and the potential for serious adverse effects, these agents probably should be limited to patients with treatment-resistant depression for whom a statin is indicated for a comorbid medical disorder, such as hypercholesteremia.

Neurosteroids

Brexanolone is FDA-approved for the treatment of postpartum depression. It is an IV formulation of the neuroactive steroid hormone allopregnanolone (a metabolite of progesterone), which acts as a positive allosteric modulator of the GABA-A receptor. Unfortunately, the infusion needs to occur over a 60-hour period.

Ganaxolone is an oral analog formulation of allopregnanolone. In an uncontrolled, open-label pilot study, this medication was administered for 8 weeks as an adjunct to an adequately dosed antidepressant to 10 postmenopausal women with persistent MDD.¹⁶ Of the 9 women who completed the study, 4 (44%) improved significantly (P < .019) and the benefit was sustained for 2 additional weeks.¹⁶ Adverse effects of ganaxolone included dizziness in 60% of participants, and sleepiness and fatigue in all of them with twice-daily dosing. If the FDA approves ganaxolone, it would become an easier-to-administer option to brexanolone.

Zuranolone is an investigational agent being studied as a treatment for postpartum depression. In a double-blind RCT that evaluated 151 women with postpartum depression, those who took oral zuranolone, 30 mg daily at bedtime for 2 weeks, experienced significant reductions in Hamilton Depression Rating Scale-17 (HDRS-17) scores compared with placebo (P < .003).¹⁷ Improvement in core depression symptom ratings was seen as early as Day 3 and persisted through Day 45.

Continue to: The most common...

The most common (≥5%) treatment-emergent adverse effects were somnolence (15%), headache (9%), dizziness (8%), upper respiratory tract infection (8%), diarrhea (6%), and sedation (5%). Two patients experienced a serious adverse event: one who received zuranolone (confusional state) and one who received placebo (pancreatitis). One patient discontinued zuranolone due to adverse effects vs no discontinuations among those who received placebo. The risk of taking zuranolone while breastfeeding is not known.

Device-based strategies

In addition to FDA-cleared approaches (eg, electroconvulsive therapy [ECT], vagus nerve stimulation [VNS], transcranial magnetic stimulation [TMS]), other devices have also demonstrated promising results.

Transcranial direct current stimulation (tDCS) involves delivering weak electrical current to the cerebral cortex through small scalp electrodes to produce the following effects:

• anodal tDCS enhances cortical excitability
• cathodal tDCS reduces cortical excitability.

A typical protocol consists of delivering 1 to 2 mA over 20 minutes with scalp electrodes placed in different configurations based on the targeted symptom(s).

While tDCS has been evaluated as a treatment for various neuropsychiatric disorders, including bipolar depression, Parkinson’s disease, and schizophrenia, most trials have looked at its use for treating depression. Results have been promising but mixed. For example, 1 meta-analysis of 6 RCTs (comprising 96 active and 80 sham tDCS courses) reported that active tDCS was superior to a sham procedure (Hedges’ g = 0.743) for symptoms of depression.¹⁸ By contrast, another meta-analysis of 6 RCTs (N = 200) did not find a significant difference between active and sham tDCS for response and remission rates.¹⁹ More recently, a group of experts created an evidence-based guideline using a systematic review of the controlled trial literature. These authors concluded there is “probable efficacy for anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC) (with right orbitofrontal cathode) in major depressive episodes without drug resistance but probable inefficacy for drug-resistant major depressive episodes.”²⁰

Continue to: Adverse effects of tDCS...

Adverse effects of tDCS are typically mild but may include persistent skin lesions similar to burns; mania or hypomania; and one reported seizure in a pediatric patient.

Because various over-the-counter direct current stimulation devices are available for purchase at modest cost, clinicians should ask patients if they have been self-administering this treatment.

Chronotherapy strategies

Agomelatine combines serotonergic (5-HT2B and 5-HT2C antagonist) and melatonergic (MT1-MT2 agonist in the suprachiasmatic nucleus) actions that contribute to stabilization of circadian rhythms and subsequent improvement in sleep patterns. Agomelatine (n = 1,274) significantly lowered depression symptoms compared with placebo (n = 689) (standardized mean difference −0.26; P < 3.48×10^-11), but the clinical relevance was questionable.²¹ A recent review of the literature and expert opinion suggest this agent may also have efficacy for anhedonia; however, in placebo-controlled, relapse prevention studies, its long-term efficacy was not consistent.²²

Common adverse effects include anxiety; nausea, vomiting, and stomach pain; abnormal dreams and insomnia; dizziness; drowsiness and fatigue; and weight gain. Some reviewers have expressed concerns about agomelatine’s potential for hepatotoxicity and the need for repeated clinical laboratory tests. Although agomelatine is approved outside of the United States, limited efficacy data and the potential for serious adverse effects have precluded FDA approval of this agent.

Sleep deprivation as a treatment technique for depression has been developed over the past 50 years. With total sleep deprivation (TSD) over 1 cycle, patients stay awake for approximately 36 hours, from daytime until the next day’s evening. While 1 to 6 cycles can produce acute antidepressant effects, prompt relapse after sleep recovery is common.

Continue to: In a systematic review...

In a systematic review and meta-analysis of 7 studies that included a total of 311 patients with bipolar depression²³:

• TSD plus medications resulted in a significant decrease in depressive symptoms at 1 week compared with medications alone
• higher response rates were maintained after 3 months with lithium.

Adverse effects commonly include general fatigue and headaches; possible switch into mania with bipolar depression; and rarely, seizures or other unexpected medical conditions (eg, acute coronary syndrome). Presently, this approach is limited to research laboratories with the appropriate sophistication to safely conduct such trials.

Other nontraditional strategies

Cardiovascular exercise, resistance training, mindfulness, and yoga have been shown to decrease severe depressive symptoms when used as adjuncts for patients with treatment-resistant depression, or as monotherapy to treat patients with milder depression.

Exercise. The significant benefits of exercise in various forms as treatment for mild to moderate depression are well described in the literature, but it is less clear if it is effective for treatment-resistant depression. A 2013 Cochrane report²⁴ (39 studies with 2,326 participants total) and 2 meta-analyses undertaken in 2015 (Kvam et al²⁵ included 23 studies with 977 participants, and Schuh et al²⁶ included 25 trials with 1,487 participants) reported that various types of exercise ameliorate depression of differing subtypes and severity, with effect sizes ranging from small to large. Schuh et al²⁶ found that publication bias underestimated effect size. Also, not surprisingly, separate analysis of only higher-quality trials decreased effect size.^24-26 A meta-analysis that included tai chi and yoga in addition to aerobic exercise and strength training (25 trials with 2,083 participants) found low to moderate benefit for exercise and yoga.²⁷ Finally, a meta-analysis by Cramer et al²⁸ that included 12 RCTs (N = 619) supported the use of yoga plus controlled breathing techniques as an ancillary treatment for depression.

Two small exercise trials specifically evaluated patients with treatment-resistant depression.^29,30 Mota-Pereira et al²⁹ compared 22 participants who walked for 30 to 45 minutes, 5 days a week for 12 weeks in addition to pharmacotherapy with 11 patients who received pharmacotherapy only. Exercise improved all outcomes, including HDRS score (both compared to baseline and to the control group). Moreover, 26% of the exercise group went into remission. Pilu et al³⁰ evaluated strength training as an adjunctive treatment. Participants received 1 hour of strength training twice weekly for 8 months (n = 10), or pharmacotherapy only (n = 20). The adjunct strength training group had a statistically significant (P < .0001) improvement in HDRS scores at the end of the 8 months, whereas the control group did not (P < .28).

Continue to: Adverse effects...

Adverse effects of exercise are typically limited to sprains or strains; rarely, participants experience serious injuries.

Mindfulness-based interventions involve purposely paying attention in the present moment to enhance self-understanding and decrease anxiety about the future and regrets about the past, both of which complicate depression. A meta-analysis of 12 RCTs (N = 578) found this approach significantly reduced depression severity when used as an adjunctive therapy.³¹ There may be risks if mindfulness-based interventions are practiced incorrectly. For example, some reports have linked mindfulness-based interventions to psychotic episodes, meditation addiction, and antisocial or asocial behavior.³²

Bottom Line

Nonpharmacologic options for patients with treatment-resistant depression include herbal/nutraceuticals, anti-inflammatory/immune system therapies, and devices. While research suggests some of these approaches are promising, clinicians need to carefully consider potential adverse effects, some of which may be serious.

Related Resources

• Kaur M, Sanches M. Experimental therapeutics in treatmentresistant major depressive disorder. J Exp Pharmacol. 2021;13:181-196.
• Janicak PG. What’s new in transcranial magnetic stimulation. Current Psychiatry. 2019;18(3):10-16.

Drug Brand Names

Atorvastatin • Lipitor
Brexanolone • Zulresso
Citalopram • Celexa
Fluoxetine • Prozac
Lithium • Eskalith, Lithobid
Lovastatin • Altoprev, Mevacor
Minocycline • Dynacin, Minocin
Simvastatin • Flolipid, Zocor

[embed:render:related:node:244798]

[embed:render:related:node:195221]

When patients with major depressive disorder (MDD) do not achieve optimal outcomes after FDA-approved first-line treatments and standard adjunctive strategies, clinicians look for additional approaches to alleviate their patients’ symptoms. Recent research suggests that several “nontraditional” treatments used primarily as adjuncts to standard antidepressants have promise for treatment-resistant depression.

In Part 1 of this article (Current Psychiatry, September 2021), we examined off-label medications. In Part 2, we will review other nontraditional approaches to treatment-resistant depression, including herbal/nutraceutical agents, anti-inflammatory/immune system therapies, device-based treatments, and other alternative approaches. Importantly, some treatments also demonstrate adverse effects (Table^1-32). With a careful consideration of the risk/benefit balance, this article reviews some of the better-studied nontraditional treatment options for patients with treatment-resistant depression.

CP02010032_t1.PNG

Herbal/nutraceutical agents

This category encompasses a variety of commonly available “natural” options patients often ask about and at times self-prescribe. Examples evaluated in clinical trials include:

• vitamin D
• essential fatty acids (omega-3, omega-6)
• S-adenosyl-L-methionine (SAMe)
• hypericum perforatum (St. John’s Wort)
• probiotics.

Vitamin D deficiency has been linked to depression, possibly by lowering serotonin, norepinephrine, and dopamine concentrations.^1-3

A meta-analysis of 3 prospective, observational studies (N = 8,815) found an elevated risk of affective disorders in patients with low vitamin D levels.⁴ In addition, a systematic review and meta-analysis supported a potential role for vitamin D supplementation for patients with treatment-resistant depresssion.⁵

Toxicity can occur at levels >100 ng/mL, and resulting adverse effects may include weakness, fatigue, sleepiness, headache, loss of appetite, dry mouth, metallic taste, nausea, and vomiting. This vitamin can be considered as an adjunct to standard antidepressants, particularly in patients with treatment-resistant depression who have low vitamin D levels, but regular monitoring is necessary to avoid toxicity.

Essential fatty acids. Protein receptors embedded in lipid membranes and their binding affinities are influenced by omega-3 and omega-6 polyunsaturated fatty acids. Thus, essential fatty acids may benefit depression by maintaining membrane integrity and fluidity, as well as via their anti-inflammatory activity.

Continue to: Although results from...

Although results from controlled trials are mixed, a systematic review and meta-analysis of adjunctive nutraceuticals supported a potential role for essential fatty acids, primarily eicosapentaenoic acid (EPA), by itself or in combination with docosahexaenoic acid (DHA), with total EPA >60%.⁵ A second meta-analysis of 26 studies (N = 2,160) that considered only essential fatty acids concluded that EPA ≥60% at ≤1 g/d could benefit depression.⁶ Furthermore, omega-3 fatty acids may be helpful as an add-on agent for postpartum depression.⁷

Be aware that a diet rich in omega-6 greatly increases oxidized low-density lipoprotein levels in adipose tissue, potentially posing a cardiac risk factor. Clinicians need to be aware that self-prescribed use of essential fatty acids is common, and to ask about and monitor their patients’ use of these agents.

S-adenosyl-L-methionine (SAMe) is an intracellular amino acid and methyl donor. Among other actions, it is involved in the biosynthesis of hormones and neurotransmitters. There is promising but limited preliminary evidence of its efficacy and safety as a monotherapy or for antidepressant augmentation.⁸ For example, when compared with placebo for depressive symptoms in 19 randomized controlled trials (RCTs) (N = 878) ⁸:

• Five out of 6 earlier controlled studies reported SAMe IV (200 to 400 mg/d) or IM (45 to 50 mg/d) was more effective than placebo
• When the above studies were added to 14 subsequent studies for a meta-analysis, 12 of 19 RCTs reported that parenteral or oral SAMe was significantly more effective than placebo for depression (P < .05).

Overall, the safety and tolerability of SAMe are good. Common adverse effects include nausea, mild insomnia, dizziness, irritability, and anxiety. This is another compound widely available without a prescription and at times self-prescribed. It carries an acceptable risk/benefit balance, with decades of experience.

Hypericum perforatum (St. John’s Wort) is widely prescribed for depression in China and Europe, typically in doses ranging from 500 to 900 mg/d. Its mechanism of action in depression may relate to inhibition of serotonin, dopamine, and norepinephrine uptake from the synaptic cleft of these interconnecting neurotransmitter systems.

Continue to: A meta-analysis of 7 clinical trials...

A meta-analysis of 7 clinical trials (N = 3,808) comparing St. John’s Wort with various selective serotonin reuptake inhibitors (SSRIs) reported comparable rates of response (pooled relative risk .983, 95% CI .924 to 1.042; P < .001) and remission (pooled relative risk 1.013, 95% CI .892 to 1.134; P < .001).⁹ Further, there were significantly lower discontinuation/dropout rates (pooled odds ratio .587, 95% CI .478 to 0.697; P < .001) for St. John’s Wort compared with the SSRIs.

Existing evidence on the long-term efficacy and safety is limited (studies ranged from 4 to 12 weeks), as is evidence for patients with more severe depression or high suicidality.

Serious drug interactions include the potential for serotonin syndrome when St. John’s Wort is combined with certain antidepressants, compromised efficacy of benzodiazepines and standard antidepressants, and severe skin reactions to sun exposure. In addition, St. John’s Wort may not be safe to use during pregnancy or while breastfeeding. Because potential drug interactions can be serious and individuals often self-prescribe this agent, it is important to ask patients about their use of St. John’s Wort, and to be vigilant for such potential adverse interactions.

Probiotics. These agents produce neuroactive substances that act on the brain/gut axis. Preliminary evidence suggests that these “psychobiotics” confer mental health benefits.^10-12 Relative to other approaches, their low-risk profile make them an attractive option for some patients.

Anti-inflammatory/immune system therapies

Inflammation is linked to various medical and brain disorders. For example, patients with depression often demonstrate increased levels of peripheral blood inflammatory biomarkers (such as C-reactive protein and interleukin-6 and -17) that are known to alter norepinephrine, neuroendocrine (eg, the hypothalamic-pituitary-adrenal axis), and microglia function in addition to neuro­plasticity. Thus, targeting inflammation may facilitate the development of novel antidepressants. In addition, these agents may benefit depression associated with comorbid autoimmune disorders, such as psoriasis or rheumatoid arthritis. A systematic review and meta-analysis of 36 RCTs (N = 10,000) found 5 out of 6 anti-inflammatory agents improved depression.^13,14 In general, reported disadvantages of anti-inflammatories/immunosuppressants include the potential to block the antidepressant effect of some agents, the risk of opportunistic infections, and an increased risk of suicide.

Continue to: Statins

In a meta-analysis of 3 randomized, double-blind trials, 3 statins (lovastatin, atorvastatin, and simvastatin) significantly improved depression scores when used as an adjunctive therapy to fluoxetine and citalopram, compared with adjunctive placebo (N = 165, P < .001).¹⁵

Specific adverse effects of statins include headaches, muscle pain (rarely rhabdomyolysis), dizziness, rash, and liver damage. Statins also have the potential for adverse interactions with other medications. Given the limited efficacy literature on statins for depression and the potential for serious adverse effects, these agents probably should be limited to patients with treatment-resistant depression for whom a statin is indicated for a comorbid medical disorder, such as hypercholesteremia.

Neurosteroids

Brexanolone is FDA-approved for the treatment of postpartum depression. It is an IV formulation of the neuroactive steroid hormone allopregnanolone (a metabolite of progesterone), which acts as a positive allosteric modulator of the GABA-A receptor. Unfortunately, the infusion needs to occur over a 60-hour period.

Ganaxolone is an oral analog formulation of allopregnanolone. In an uncontrolled, open-label pilot study, this medication was administered for 8 weeks as an adjunct to an adequately dosed antidepressant to 10 postmenopausal women with persistent MDD.¹⁶ Of the 9 women who completed the study, 4 (44%) improved significantly (P < .019) and the benefit was sustained for 2 additional weeks.¹⁶ Adverse effects of ganaxolone included dizziness in 60% of participants, and sleepiness and fatigue in all of them with twice-daily dosing. If the FDA approves ganaxolone, it would become an easier-to-administer option to brexanolone.

Zuranolone is an investigational agent being studied as a treatment for postpartum depression. In a double-blind RCT that evaluated 151 women with postpartum depression, those who took oral zuranolone, 30 mg daily at bedtime for 2 weeks, experienced significant reductions in Hamilton Depression Rating Scale-17 (HDRS-17) scores compared with placebo (P < .003).¹⁷ Improvement in core depression symptom ratings was seen as early as Day 3 and persisted through Day 45.

Continue to: The most common...

The most common (≥5%) treatment-emergent adverse effects were somnolence (15%), headache (9%), dizziness (8%), upper respiratory tract infection (8%), diarrhea (6%), and sedation (5%). Two patients experienced a serious adverse event: one who received zuranolone (confusional state) and one who received placebo (pancreatitis). One patient discontinued zuranolone due to adverse effects vs no discontinuations among those who received placebo. The risk of taking zuranolone while breastfeeding is not known.

Device-based strategies

In addition to FDA-cleared approaches (eg, electroconvulsive therapy [ECT], vagus nerve stimulation [VNS], transcranial magnetic stimulation [TMS]), other devices have also demonstrated promising results.

Transcranial direct current stimulation (tDCS) involves delivering weak electrical current to the cerebral cortex through small scalp electrodes to produce the following effects:

• anodal tDCS enhances cortical excitability
• cathodal tDCS reduces cortical excitability.

A typical protocol consists of delivering 1 to 2 mA over 20 minutes with scalp electrodes placed in different configurations based on the targeted symptom(s).

While tDCS has been evaluated as a treatment for various neuropsychiatric disorders, including bipolar depression, Parkinson’s disease, and schizophrenia, most trials have looked at its use for treating depression. Results have been promising but mixed. For example, 1 meta-analysis of 6 RCTs (comprising 96 active and 80 sham tDCS courses) reported that active tDCS was superior to a sham procedure (Hedges’ g = 0.743) for symptoms of depression.¹⁸ By contrast, another meta-analysis of 6 RCTs (N = 200) did not find a significant difference between active and sham tDCS for response and remission rates.¹⁹ More recently, a group of experts created an evidence-based guideline using a systematic review of the controlled trial literature. These authors concluded there is “probable efficacy for anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC) (with right orbitofrontal cathode) in major depressive episodes without drug resistance but probable inefficacy for drug-resistant major depressive episodes.”²⁰

Continue to: Adverse effects of tDCS...

Adverse effects of tDCS are typically mild but may include persistent skin lesions similar to burns; mania or hypomania; and one reported seizure in a pediatric patient.

Because various over-the-counter direct current stimulation devices are available for purchase at modest cost, clinicians should ask patients if they have been self-administering this treatment.

Chronotherapy strategies

Agomelatine combines serotonergic (5-HT2B and 5-HT2C antagonist) and melatonergic (MT1-MT2 agonist in the suprachiasmatic nucleus) actions that contribute to stabilization of circadian rhythms and subsequent improvement in sleep patterns. Agomelatine (n = 1,274) significantly lowered depression symptoms compared with placebo (n = 689) (standardized mean difference −0.26; P < 3.48×10^-11), but the clinical relevance was questionable.²¹ A recent review of the literature and expert opinion suggest this agent may also have efficacy for anhedonia; however, in placebo-controlled, relapse prevention studies, its long-term efficacy was not consistent.²²

Common adverse effects include anxiety; nausea, vomiting, and stomach pain; abnormal dreams and insomnia; dizziness; drowsiness and fatigue; and weight gain. Some reviewers have expressed concerns about agomelatine’s potential for hepatotoxicity and the need for repeated clinical laboratory tests. Although agomelatine is approved outside of the United States, limited efficacy data and the potential for serious adverse effects have precluded FDA approval of this agent.

Sleep deprivation as a treatment technique for depression has been developed over the past 50 years. With total sleep deprivation (TSD) over 1 cycle, patients stay awake for approximately 36 hours, from daytime until the next day’s evening. While 1 to 6 cycles can produce acute antidepressant effects, prompt relapse after sleep recovery is common.

Continue to: In a systematic review...

In a systematic review and meta-analysis of 7 studies that included a total of 311 patients with bipolar depression²³:

• TSD plus medications resulted in a significant decrease in depressive symptoms at 1 week compared with medications alone
• higher response rates were maintained after 3 months with lithium.

Adverse effects commonly include general fatigue and headaches; possible switch into mania with bipolar depression; and rarely, seizures or other unexpected medical conditions (eg, acute coronary syndrome). Presently, this approach is limited to research laboratories with the appropriate sophistication to safely conduct such trials.

Other nontraditional strategies

Cardiovascular exercise, resistance training, mindfulness, and yoga have been shown to decrease severe depressive symptoms when used as adjuncts for patients with treatment-resistant depression, or as monotherapy to treat patients with milder depression.

Exercise. The significant benefits of exercise in various forms as treatment for mild to moderate depression are well described in the literature, but it is less clear if it is effective for treatment-resistant depression. A 2013 Cochrane report²⁴ (39 studies with 2,326 participants total) and 2 meta-analyses undertaken in 2015 (Kvam et al²⁵ included 23 studies with 977 participants, and Schuh et al²⁶ included 25 trials with 1,487 participants) reported that various types of exercise ameliorate depression of differing subtypes and severity, with effect sizes ranging from small to large. Schuh et al²⁶ found that publication bias underestimated effect size. Also, not surprisingly, separate analysis of only higher-quality trials decreased effect size.^24-26 A meta-analysis that included tai chi and yoga in addition to aerobic exercise and strength training (25 trials with 2,083 participants) found low to moderate benefit for exercise and yoga.²⁷ Finally, a meta-analysis by Cramer et al²⁸ that included 12 RCTs (N = 619) supported the use of yoga plus controlled breathing techniques as an ancillary treatment for depression.

Two small exercise trials specifically evaluated patients with treatment-resistant depression.^29,30 Mota-Pereira et al²⁹ compared 22 participants who walked for 30 to 45 minutes, 5 days a week for 12 weeks in addition to pharmacotherapy with 11 patients who received pharmacotherapy only. Exercise improved all outcomes, including HDRS score (both compared to baseline and to the control group). Moreover, 26% of the exercise group went into remission. Pilu et al³⁰ evaluated strength training as an adjunctive treatment. Participants received 1 hour of strength training twice weekly for 8 months (n = 10), or pharmacotherapy only (n = 20). The adjunct strength training group had a statistically significant (P < .0001) improvement in HDRS scores at the end of the 8 months, whereas the control group did not (P < .28).

Continue to: Adverse effects...

Adverse effects of exercise are typically limited to sprains or strains; rarely, participants experience serious injuries.

Mindfulness-based interventions involve purposely paying attention in the present moment to enhance self-understanding and decrease anxiety about the future and regrets about the past, both of which complicate depression. A meta-analysis of 12 RCTs (N = 578) found this approach significantly reduced depression severity when used as an adjunctive therapy.³¹ There may be risks if mindfulness-based interventions are practiced incorrectly. For example, some reports have linked mindfulness-based interventions to psychotic episodes, meditation addiction, and antisocial or asocial behavior.³²

Bottom Line

Nonpharmacologic options for patients with treatment-resistant depression include herbal/nutraceuticals, anti-inflammatory/immune system therapies, and devices. While research suggests some of these approaches are promising, clinicians need to carefully consider potential adverse effects, some of which may be serious.

Related Resources

• Kaur M, Sanches M. Experimental therapeutics in treatmentresistant major depressive disorder. J Exp Pharmacol. 2021;13:181-196.
• Janicak PG. What’s new in transcranial magnetic stimulation. Current Psychiatry. 2019;18(3):10-16.

Drug Brand Names

Atorvastatin • Lipitor
Brexanolone • Zulresso
Citalopram • Celexa
Fluoxetine • Prozac
Lithium • Eskalith, Lithobid
Lovastatin • Altoprev, Mevacor
Minocycline • Dynacin, Minocin
Simvastatin • Flolipid, Zocor

[embed:render:related:node:244798]

[embed:render:related:node:195221]

When patients with major depressive disorder (MDD) do not achieve optimal outcomes after FDA-approved first-line treatments and standard adjunctive strategies, clinicians look for additional approaches to alleviate their patients’ symptoms. Recent research suggests that several “nontraditional” treatments used primarily as adjuncts to standard antidepressants have promise for treatment-resistant depression.

In Part 1 of this article (Current Psychiatry, September 2021), we examined off-label medications. In Part 2, we will review other nontraditional approaches to treatment-resistant depression, including herbal/nutraceutical agents, anti-inflammatory/immune system therapies, device-based treatments, and other alternative approaches. Importantly, some treatments also demonstrate adverse effects (Table^1-32). With a careful consideration of the risk/benefit balance, this article reviews some of the better-studied nontraditional treatment options for patients with treatment-resistant depression.

CP02010032_t1.PNG

Herbal/nutraceutical agents

This category encompasses a variety of commonly available “natural” options patients often ask about and at times self-prescribe. Examples evaluated in clinical trials include:

• vitamin D
• essential fatty acids (omega-3, omega-6)
• S-adenosyl-L-methionine (SAMe)
• hypericum perforatum (St. John’s Wort)
• probiotics.

Vitamin D deficiency has been linked to depression, possibly by lowering serotonin, norepinephrine, and dopamine concentrations.^1-3

A meta-analysis of 3 prospective, observational studies (N = 8,815) found an elevated risk of affective disorders in patients with low vitamin D levels.⁴ In addition, a systematic review and meta-analysis supported a potential role for vitamin D supplementation for patients with treatment-resistant depresssion.⁵

Toxicity can occur at levels >100 ng/mL, and resulting adverse effects may include weakness, fatigue, sleepiness, headache, loss of appetite, dry mouth, metallic taste, nausea, and vomiting. This vitamin can be considered as an adjunct to standard antidepressants, particularly in patients with treatment-resistant depression who have low vitamin D levels, but regular monitoring is necessary to avoid toxicity.

Essential fatty acids. Protein receptors embedded in lipid membranes and their binding affinities are influenced by omega-3 and omega-6 polyunsaturated fatty acids. Thus, essential fatty acids may benefit depression by maintaining membrane integrity and fluidity, as well as via their anti-inflammatory activity.

Continue to: Although results from...

Although results from controlled trials are mixed, a systematic review and meta-analysis of adjunctive nutraceuticals supported a potential role for essential fatty acids, primarily eicosapentaenoic acid (EPA), by itself or in combination with docosahexaenoic acid (DHA), with total EPA >60%.⁵ A second meta-analysis of 26 studies (N = 2,160) that considered only essential fatty acids concluded that EPA ≥60% at ≤1 g/d could benefit depression.⁶ Furthermore, omega-3 fatty acids may be helpful as an add-on agent for postpartum depression.⁷

Be aware that a diet rich in omega-6 greatly increases oxidized low-density lipoprotein levels in adipose tissue, potentially posing a cardiac risk factor. Clinicians need to be aware that self-prescribed use of essential fatty acids is common, and to ask about and monitor their patients’ use of these agents.

S-adenosyl-L-methionine (SAMe) is an intracellular amino acid and methyl donor. Among other actions, it is involved in the biosynthesis of hormones and neurotransmitters. There is promising but limited preliminary evidence of its efficacy and safety as a monotherapy or for antidepressant augmentation.⁸ For example, when compared with placebo for depressive symptoms in 19 randomized controlled trials (RCTs) (N = 878) ⁸:

• Five out of 6 earlier controlled studies reported SAMe IV (200 to 400 mg/d) or IM (45 to 50 mg/d) was more effective than placebo
• When the above studies were added to 14 subsequent studies for a meta-analysis, 12 of 19 RCTs reported that parenteral or oral SAMe was significantly more effective than placebo for depression (P < .05).

Overall, the safety and tolerability of SAMe are good. Common adverse effects include nausea, mild insomnia, dizziness, irritability, and anxiety. This is another compound widely available without a prescription and at times self-prescribed. It carries an acceptable risk/benefit balance, with decades of experience.

Hypericum perforatum (St. John’s Wort) is widely prescribed for depression in China and Europe, typically in doses ranging from 500 to 900 mg/d. Its mechanism of action in depression may relate to inhibition of serotonin, dopamine, and norepinephrine uptake from the synaptic cleft of these interconnecting neurotransmitter systems.

Continue to: A meta-analysis of 7 clinical trials...

A meta-analysis of 7 clinical trials (N = 3,808) comparing St. John’s Wort with various selective serotonin reuptake inhibitors (SSRIs) reported comparable rates of response (pooled relative risk .983, 95% CI .924 to 1.042; P < .001) and remission (pooled relative risk 1.013, 95% CI .892 to 1.134; P < .001).⁹ Further, there were significantly lower discontinuation/dropout rates (pooled odds ratio .587, 95% CI .478 to 0.697; P < .001) for St. John’s Wort compared with the SSRIs.

Existing evidence on the long-term efficacy and safety is limited (studies ranged from 4 to 12 weeks), as is evidence for patients with more severe depression or high suicidality.

Serious drug interactions include the potential for serotonin syndrome when St. John’s Wort is combined with certain antidepressants, compromised efficacy of benzodiazepines and standard antidepressants, and severe skin reactions to sun exposure. In addition, St. John’s Wort may not be safe to use during pregnancy or while breastfeeding. Because potential drug interactions can be serious and individuals often self-prescribe this agent, it is important to ask patients about their use of St. John’s Wort, and to be vigilant for such potential adverse interactions.

Probiotics. These agents produce neuroactive substances that act on the brain/gut axis. Preliminary evidence suggests that these “psychobiotics” confer mental health benefits.^10-12 Relative to other approaches, their low-risk profile make them an attractive option for some patients.

Anti-inflammatory/immune system therapies

Inflammation is linked to various medical and brain disorders. For example, patients with depression often demonstrate increased levels of peripheral blood inflammatory biomarkers (such as C-reactive protein and interleukin-6 and -17) that are known to alter norepinephrine, neuroendocrine (eg, the hypothalamic-pituitary-adrenal axis), and microglia function in addition to neuro­plasticity. Thus, targeting inflammation may facilitate the development of novel antidepressants. In addition, these agents may benefit depression associated with comorbid autoimmune disorders, such as psoriasis or rheumatoid arthritis. A systematic review and meta-analysis of 36 RCTs (N = 10,000) found 5 out of 6 anti-inflammatory agents improved depression.^13,14 In general, reported disadvantages of anti-inflammatories/immunosuppressants include the potential to block the antidepressant effect of some agents, the risk of opportunistic infections, and an increased risk of suicide.

Continue to: Statins

In a meta-analysis of 3 randomized, double-blind trials, 3 statins (lovastatin, atorvastatin, and simvastatin) significantly improved depression scores when used as an adjunctive therapy to fluoxetine and citalopram, compared with adjunctive placebo (N = 165, P < .001).¹⁵

Specific adverse effects of statins include headaches, muscle pain (rarely rhabdomyolysis), dizziness, rash, and liver damage. Statins also have the potential for adverse interactions with other medications. Given the limited efficacy literature on statins for depression and the potential for serious adverse effects, these agents probably should be limited to patients with treatment-resistant depression for whom a statin is indicated for a comorbid medical disorder, such as hypercholesteremia.

Neurosteroids

Brexanolone is FDA-approved for the treatment of postpartum depression. It is an IV formulation of the neuroactive steroid hormone allopregnanolone (a metabolite of progesterone), which acts as a positive allosteric modulator of the GABA-A receptor. Unfortunately, the infusion needs to occur over a 60-hour period.

Ganaxolone is an oral analog formulation of allopregnanolone. In an uncontrolled, open-label pilot study, this medication was administered for 8 weeks as an adjunct to an adequately dosed antidepressant to 10 postmenopausal women with persistent MDD.¹⁶ Of the 9 women who completed the study, 4 (44%) improved significantly (P < .019) and the benefit was sustained for 2 additional weeks.¹⁶ Adverse effects of ganaxolone included dizziness in 60% of participants, and sleepiness and fatigue in all of them with twice-daily dosing. If the FDA approves ganaxolone, it would become an easier-to-administer option to brexanolone.

Zuranolone is an investigational agent being studied as a treatment for postpartum depression. In a double-blind RCT that evaluated 151 women with postpartum depression, those who took oral zuranolone, 30 mg daily at bedtime for 2 weeks, experienced significant reductions in Hamilton Depression Rating Scale-17 (HDRS-17) scores compared with placebo (P < .003).¹⁷ Improvement in core depression symptom ratings was seen as early as Day 3 and persisted through Day 45.

Continue to: The most common...

The most common (≥5%) treatment-emergent adverse effects were somnolence (15%), headache (9%), dizziness (8%), upper respiratory tract infection (8%), diarrhea (6%), and sedation (5%). Two patients experienced a serious adverse event: one who received zuranolone (confusional state) and one who received placebo (pancreatitis). One patient discontinued zuranolone due to adverse effects vs no discontinuations among those who received placebo. The risk of taking zuranolone while breastfeeding is not known.

Device-based strategies

In addition to FDA-cleared approaches (eg, electroconvulsive therapy [ECT], vagus nerve stimulation [VNS], transcranial magnetic stimulation [TMS]), other devices have also demonstrated promising results.

Transcranial direct current stimulation (tDCS) involves delivering weak electrical current to the cerebral cortex through small scalp electrodes to produce the following effects:

• anodal tDCS enhances cortical excitability
• cathodal tDCS reduces cortical excitability.

A typical protocol consists of delivering 1 to 2 mA over 20 minutes with scalp electrodes placed in different configurations based on the targeted symptom(s).

While tDCS has been evaluated as a treatment for various neuropsychiatric disorders, including bipolar depression, Parkinson’s disease, and schizophrenia, most trials have looked at its use for treating depression. Results have been promising but mixed. For example, 1 meta-analysis of 6 RCTs (comprising 96 active and 80 sham tDCS courses) reported that active tDCS was superior to a sham procedure (Hedges’ g = 0.743) for symptoms of depression.¹⁸ By contrast, another meta-analysis of 6 RCTs (N = 200) did not find a significant difference between active and sham tDCS for response and remission rates.¹⁹ More recently, a group of experts created an evidence-based guideline using a systematic review of the controlled trial literature. These authors concluded there is “probable efficacy for anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC) (with right orbitofrontal cathode) in major depressive episodes without drug resistance but probable inefficacy for drug-resistant major depressive episodes.”²⁰

Continue to: Adverse effects of tDCS...

Adverse effects of tDCS are typically mild but may include persistent skin lesions similar to burns; mania or hypomania; and one reported seizure in a pediatric patient.

Because various over-the-counter direct current stimulation devices are available for purchase at modest cost, clinicians should ask patients if they have been self-administering this treatment.

Chronotherapy strategies

Agomelatine combines serotonergic (5-HT2B and 5-HT2C antagonist) and melatonergic (MT1-MT2 agonist in the suprachiasmatic nucleus) actions that contribute to stabilization of circadian rhythms and subsequent improvement in sleep patterns. Agomelatine (n = 1,274) significantly lowered depression symptoms compared with placebo (n = 689) (standardized mean difference −0.26; P < 3.48×10^-11), but the clinical relevance was questionable.²¹ A recent review of the literature and expert opinion suggest this agent may also have efficacy for anhedonia; however, in placebo-controlled, relapse prevention studies, its long-term efficacy was not consistent.²²

Common adverse effects include anxiety; nausea, vomiting, and stomach pain; abnormal dreams and insomnia; dizziness; drowsiness and fatigue; and weight gain. Some reviewers have expressed concerns about agomelatine’s potential for hepatotoxicity and the need for repeated clinical laboratory tests. Although agomelatine is approved outside of the United States, limited efficacy data and the potential for serious adverse effects have precluded FDA approval of this agent.

Sleep deprivation as a treatment technique for depression has been developed over the past 50 years. With total sleep deprivation (TSD) over 1 cycle, patients stay awake for approximately 36 hours, from daytime until the next day’s evening. While 1 to 6 cycles can produce acute antidepressant effects, prompt relapse after sleep recovery is common.

Continue to: In a systematic review...

In a systematic review and meta-analysis of 7 studies that included a total of 311 patients with bipolar depression²³:

• TSD plus medications resulted in a significant decrease in depressive symptoms at 1 week compared with medications alone
• higher response rates were maintained after 3 months with lithium.

Adverse effects commonly include general fatigue and headaches; possible switch into mania with bipolar depression; and rarely, seizures or other unexpected medical conditions (eg, acute coronary syndrome). Presently, this approach is limited to research laboratories with the appropriate sophistication to safely conduct such trials.

Other nontraditional strategies

Cardiovascular exercise, resistance training, mindfulness, and yoga have been shown to decrease severe depressive symptoms when used as adjuncts for patients with treatment-resistant depression, or as monotherapy to treat patients with milder depression.

Exercise. The significant benefits of exercise in various forms as treatment for mild to moderate depression are well described in the literature, but it is less clear if it is effective for treatment-resistant depression. A 2013 Cochrane report²⁴ (39 studies with 2,326 participants total) and 2 meta-analyses undertaken in 2015 (Kvam et al²⁵ included 23 studies with 977 participants, and Schuh et al²⁶ included 25 trials with 1,487 participants) reported that various types of exercise ameliorate depression of differing subtypes and severity, with effect sizes ranging from small to large. Schuh et al²⁶ found that publication bias underestimated effect size. Also, not surprisingly, separate analysis of only higher-quality trials decreased effect size.^24-26 A meta-analysis that included tai chi and yoga in addition to aerobic exercise and strength training (25 trials with 2,083 participants) found low to moderate benefit for exercise and yoga.²⁷ Finally, a meta-analysis by Cramer et al²⁸ that included 12 RCTs (N = 619) supported the use of yoga plus controlled breathing techniques as an ancillary treatment for depression.

Two small exercise trials specifically evaluated patients with treatment-resistant depression.^29,30 Mota-Pereira et al²⁹ compared 22 participants who walked for 30 to 45 minutes, 5 days a week for 12 weeks in addition to pharmacotherapy with 11 patients who received pharmacotherapy only. Exercise improved all outcomes, including HDRS score (both compared to baseline and to the control group). Moreover, 26% of the exercise group went into remission. Pilu et al³⁰ evaluated strength training as an adjunctive treatment. Participants received 1 hour of strength training twice weekly for 8 months (n = 10), or pharmacotherapy only (n = 20). The adjunct strength training group had a statistically significant (P < .0001) improvement in HDRS scores at the end of the 8 months, whereas the control group did not (P < .28).

Continue to: Adverse effects...

Adverse effects of exercise are typically limited to sprains or strains; rarely, participants experience serious injuries.

Mindfulness-based interventions involve purposely paying attention in the present moment to enhance self-understanding and decrease anxiety about the future and regrets about the past, both of which complicate depression. A meta-analysis of 12 RCTs (N = 578) found this approach significantly reduced depression severity when used as an adjunctive therapy.³¹ There may be risks if mindfulness-based interventions are practiced incorrectly. For example, some reports have linked mindfulness-based interventions to psychotic episodes, meditation addiction, and antisocial or asocial behavior.³²

Bottom Line

Nonpharmacologic options for patients with treatment-resistant depression include herbal/nutraceuticals, anti-inflammatory/immune system therapies, and devices. While research suggests some of these approaches are promising, clinicians need to carefully consider potential adverse effects, some of which may be serious.

Related Resources

• Kaur M, Sanches M. Experimental therapeutics in treatmentresistant major depressive disorder. J Exp Pharmacol. 2021;13:181-196.
• Janicak PG. What’s new in transcranial magnetic stimulation. Current Psychiatry. 2019;18(3):10-16.

Drug Brand Names

Atorvastatin • Lipitor
Brexanolone • Zulresso
Citalopram • Celexa
Fluoxetine • Prozac
Lithium • Eskalith, Lithobid
Lovastatin • Altoprev, Mevacor
Minocycline • Dynacin, Minocin
Simvastatin • Flolipid, Zocor

[embed:render:related:node:244798]

[embed:render:related:node:195221]

Presently, FDA-approved first-line treatments and standard adjunctive strategies (eg, lithium, thyroid supplementation, stimulants, second-generation antipsychotics) for major depressive disorder (MDD) often produce less-than-desired outcomes while carrying a potentially substantial safety and tolerability burden. The lack of clinically useful and individual-based biomarkers (eg, genetic, neurophysiological, imaging) is a major obstacle to enhancing treatment efficacy and/or decreasing associated adverse effects (AEs). While the discovery of such tools is being aggressively pursued and ultimately will facilitate a more precision-based choice of therapy, empirical strategies remain our primary approach.

In controlled trials, several nontraditional treatments used primarily as adjuncts to standard antidepressants have shown promise. These include “repurposed” (off-label) medications, herbal/nutraceuticals, anti-inflammatory/immune system therapies, device-based treatments, and other alternative approaches.

Importantly, some nontraditional treatments also demonstrate AEs (Table^1-16). With a careful consideration of the risk/benefit balance, this article reviews some of the better-studied treatment options for patients with treatment-resistant depression (TRD). In Part 1, we will examine off-label medications. In Part 2, we will review other nontraditional approaches to TRD, including herbal/nutraceuticals, anti-inflammatory/immune system therapies, device-based treatments, and other alternative approaches.

CP02009038_t1.PNG

We believe this review will help clinicians who need to formulate a different approach after their patient with depression is not helped by traditional first-, second-, and third-line treatments. The potential options discussed in Part 1 of this article are categorized based on their putative mechanism of action (MOA) for depression.

Serotonergic and noradrenergic strategies

Pimavanserin is FDA-approved for treatment of Parkinson’s psychosis. Its potential MOA as an adjunctive strategy for MDD may involve 5-HT2A antagonist and inverse agonist receptor activity, as well as lesser effects at the 5-HT2Creceptor.

A 2-stage, 5-week randomized controlled trial (RCT) (CLARITY; N = 207) found adjunctive pimavanserin (34 mg/d) produced a robust antidepressant effect vs placebo in patients whose depression did not respond to selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs).¹ Furthermore, a secondary analysis of the data suggested that pimavanserin also improved sleepiness (P < .0003) and daily functioning (P < .014) at Week 5.²

Unfortunately, two 6-week, Phase III RCTs (CLARITY-2 and -3; N = 298) did not find a statistically significant difference between active treatment and placebo. This was based on change in the primary outcome measure (Hamilton Depression Rating Scale-17 score) when adjunctive pimavanserin (34 mg/d) was added to an SSRI or SNRI in patients with TRD.³ There was, however, a significant difference favoring active treatment over placebo based on the Clinical Global Impression–Severity score.

Continue to: In these trials...

In these trials, pimavanserin was generally well-tolerated. The most common AEs were dry mouth, nausea, and headache. Pimavanserin has minimal activity at norepinephrine, dopamine, histamine, or acetylcholine receptors, thus avoiding AEs associated with these receptor interactions.

Given the mixed efficacy results of existing trials, further studies are needed to clarify this agent’s overall risk/benefit in the context of TRD.

Antihypertensive medications

Emerging data suggest that some beta-adrenergic blockers, angiotensin-inhibiting agents, and calcium antagonists are associated with a decreased incidence of depression. A large 2020 study (N = 3,747,190) used population-based Danish registries (2005 to 2015) to evaluate if any of the 41 most commonly prescribed antihypertensive medications were associated with the diagnosis of depressive disorder or use of antidepressants.⁴ These researchers found that enalapril, ramipril, amlodipine, propranolol, atenolol, bisoprolol, carvedilol (P < .001), and verapamil (P < .004) were strongly associated with a decreased risk of depression.⁴

Adverse effects across these different classes of antihypertensives are well characterized, can be substantial, and commonly are related to their impact on cardiovascular function (eg, hypotension). Clinically, these agents may be potential adjuncts for patients with TRD who need antihypertensive therapy. Their use and the choice of specific agent should only be determined in consultation with the patient’s primary care physician (PCP) or appropriate specialist.

Glutamatergic strategies

Ketamine is a dissociative anesthetic and analgesic. Its MOA for treating depression appears to occur primarily through antagonist activity at the N-methyl-D-aspartate ionotropic receptor of the glutamatergic system. There is preliminary evidence that its opioid receptor actions also may contribute to its antidepressant effect.⁵

Continue to: Many published studies...

Many published studies and reviews have described ketamine’s role for treating MDD. Several studies have reported that low-dose (0.5 mg/kg) IV ketamine infusions can rapidly attenuate severe episodes of MDD as well as associated suicidality. For example, a meta-analysis of 9 RCTs (N = 368) comparing ketamine to placebo for acute treatment of unipolar and bipolar depression reported superior therapeutic effects with active treatment at 24 hours, 72 hours, and 7 days.⁶ The response and remission rates for ketamine were 52% and 21% at 24 hours; 48% and 24% at 72 hours; and 40% and 26% at 7 days, respectively.⁶

The most commonly reported AEs during the 4 hours after ketamine infusion included⁷:

• drowsiness, dizziness, poor coordination
• blurred vision, feeling strange or unreal
• hemodynamic changes (approximately 33%)
• small but significant (P < .05) increases in psychotomimetic and dissociative symptoms.

Because some individuals use ketamine recreationally, this agent also carries the risk of abuse.

Research is ongoing on strategies for long-term maintenance ketamine treatment, and the results of both short- and long-term trials will require careful scrutiny to better assess this agent’s safety and tolerability. Clinicians should first consider esketamine—the S-enantiomer of ketamine—because an intranasal formulation of this agent is FDA-approved for treating patients with TRD or MDD with suicidality when administered in a Risk Evaluation and Mitigation Strategy–certified setting.

Cholinergic strategies

Scopolamine is a potent muscarinic receptor antagonist used to prevent nausea and vomiting caused by motion sickness or medications used during surgery. Its use for MDD is based on the theory that muscarinic receptors may be hypersensitive in mood disorders.

Continue to: Several double-blind RCTs...

Several double-blind RCTs of patients with unipolar or bipolar depression that used 3 pulsed IV infusions (4.0 mcg/kg) over 15 minutes found a rapid, robust antidepressant effect with scopolamine vs placebo.^8,9 The oral formulation might also be effective, but would not have a rapid onset.

Common adverse effects of scopolamine include agitation, dry mouth, urinary retention, and cognitive clouding. Given scopolamine’s substantial AE profile, it should be considered only for patients with TRD who could also benefit from the oral formulation for the medical indications noted above, should generally be avoided in older patients, and should be prescribed in consultation with the patient’s PCP.

Botulinum toxin. This neurotoxin inhibits acetylcholine release. It is used to treat disorders characterized by abnormal muscular contraction, such as strabismus, blepharospasm, and chronic pain syndromes. Its MOA for depression may involve its paralytic effects after injection into the glabella forehead muscle (based on the facial feedback hypothesis), as well as modulation of neurotransmitters implicated in the pathophysiology of depression.

In several small trials, injectable botulinum toxin type A (BTA) (29 units) demonstrated antidepressant effects. A recent review that considered 6 trials (N = 235; 4 of the 6 studies were RCTs, 3 of which were rated as high quality) concluded that BTA may be a promising treatment for MDD.¹⁰ Limitations of this review included lack of a priori hypotheses, small sample sizes, gender bias, and difficulty in blinding.

In clinical trials, the most common AEs included local irritation at the injection site and transient headache. This agent’s relatively mild AE profile and possible overlap when used for some of the medical indications noted above opens its potential use as an adjunct in patients with comorbid TRD.

Continue to: Endocrine strategies

Endocrine strategies

Mifepristone (RU486). This anti-glucocorticoid receptor antagonist is used as an abortifacient. Based on the theory that hyperactivity of the hypothalamic-pituitary-adrenal axis is implicated in the pathophysiology of MDD with psychotic features (psychotic depression), this agent has been studied as a treatment for this indication.

An analysis of 5 double-blind RCTs (N = 1,460) found that 7 days of mifepristone, 1,200 mg/d, was superior to placebo (P < .004) in reducing psychotic symptoms of depression.¹¹ Plasma concentrations ≥1,600 ng/mL may be required to maximize benefit.¹¹

Overall, this agent demonstrated a good safety profile in clinical trials, with treatment-emergent AEs reported in 556 (66.7%) patients who received mifepristone vs 386 (61.6%) patients who received placebo.¹¹ Common AEs included gastrointestinal (GI) symptoms, headache, and dizziness. However, 3 deaths occurred: 2 patients who received mifepristone and 1 patient who received placebo. Given this potential for a fatal outcome, clinicians should first consider prescribing an adjunctive antipsychotic agent or electroconvulsive therapy.

Estrogens. These hormones are important for sexual and reproductive development and are used to treat various sexual/reproductive disorders, primarily in women. Their role in treating depression is based on the observation that perimenopause is accompanied by an increased risk of new and recurrent depression coincident with declining ovarian function.

Evidence supports the antidepressant efficacy of transdermal estradiol plus progesterone for perimenopausal depression, but not for postmenopausal depression.^12-14 However, estrogens carry significant risks that must be carefully considered in relationship to their potential benefits. These risks include:

• vaginal bleeding, dysmenorrhea
• fibroid enlargement
• galactorrhea
• ovarian cancer, endometrial cancer, breast cancer
• deep vein thrombosis, pulmonary embolism
• hypertension, chest pain, myocardial infarction, stroke.

Continue to: The use of estrogens...

The use of estrogens as an adjunctive therapy for women with treatment-resistant perimenopausal depression should only be undertaken when standard strategies have failed, and in consultation with an endocrine specialist who can monitor for potentially serious AEs.

Opioid medications

Buprenorphine is used to treat opioid use disorder (OUD) as well as acute and chronic pain. The opioid system is involved in the regulation of mood and may be an appropriate target for novel antidepressants. The use of buprenorphine in combination with samidorphan (a preferential mu-opioid receptor antagonist) has shown initial promise for TRD while minimizing abuse potential.

Although earlier results were mixed, a pooled analysis of 2 recent large RCTs (N = 760) of patients with MDD who had not responded to antidepressants reported greater reduction in Montgomery-Åsberg Depression Rating Scale scores from baseline for active treatment (buprenorphine/samidorphan; 2 mg/2 mg) vs placebo at multiple timepoints, including end of treatment (-1.8; P < .010).¹⁵

The most common AEs included nausea, constipation, dizziness, vomiting, somnolence, fatigue, and sedation. There was minimal evidence of abuse, dependence, or opioid withdrawal. Due to the opioid crisis in the United States, the resulting relaxation of regulations regarding prescribing buprenorphine, and the high rates of depression among patients with OUD, buprenorphine/samidorphan, which is an investigational agent that is not FDA-approved, may be particularly helpful for patients with OUD who also experience comorbid TRD.

Antioxidant agents

N-acetylcysteine (NAC) is an amino acid that can treat acetaminophen toxicity and moderate hepatic damage by increasing glutathione levels. Glutathione is also the primary antioxidant in the CNS. NAC may protect against oxidative stress, chelate heavy metals, reduce inflammation, protect against mitochondrial dysfunction, inhibit apoptosis, and enhance neurogenesis, all potential pathophysiological processes that may contribute to depression.¹⁶

Continue to: A systematic review...

A systematic review and meta-analysis of 5 RCTs (N = 574) considered patients with various depression diagnoses who were randomized to adjunctive NAC, 1,000 mg twice a day, or placebo. Over 12 to 24 weeks, there was a significantly greater improvement in mood symptoms and functionality with NAC vs placebo.¹⁶

Overall, NAC was well-tolerated. The most common AEs were GI symptoms, musculoskeletal complaints, decreased energy, and headache. While NAC has been touted as a potential adjunct therapy for several psychiatric disorders, including TRD, the evidence for benefit remains limited. Given its favorable AE profile, however, and over-the-counter availability, it remains an option for select patients. It is important to ask patients if they are already taking NAC.

Options beyond off-label medications

There are a multitude of options available for addressing TRD. Many FDA-approved medications are repurposed and prescribed off-label for other indications when the risk/benefit balance is favorable. In Part 1 of this article, we reviewed several off-label medications that have supportive controlled data for treating TRD. In Part 2, we will review other nontraditional therapies for TRD, including herbal/nutraceuticals, anti-inflammatory/immune system therapies, device-based treatments, and other alternative approaches.

Bottom Line

Off-label medications that may offer benefit for patients with treatment-resistant depression (TRD) include pimavanserin, antihypertensive agents, ketamine, scopolamine, botulinum toxin, mifepristone, estrogens, buprenorphine, and N-acetylcysteine. Although some evidence supports use of these agents as adjuncts for TRD, an individualized risk/benefit analysis is required.

Related Resource

• Joshi KG, Frierson RL. Off-label prescribing: How to limit your liability. Current Psychiatry. 2020;19(9):12,39.

Drug Brand Names

Amlodipine • Katerzia, Norvasc
Atenolol • Tenormin
Bisoprolol • Zebeta
Buprenorphine • Sublocade, Subutex
Carvedilol • Coreg
Enalapril • Vasotec
Esketamine • Spravato
Estradiol transdermal • Estraderm
Ketamine • Ketalar
Mifepristone • Mifeprex
Pimavanserin • Nuplazid
Progesterone • Prometrium
Propranolol • Inderal
Ramipril • Altace
Verapamil • Calan, Verelan

[embed:render:related:node:227598]

Presently, FDA-approved first-line treatments and standard adjunctive strategies (eg, lithium, thyroid supplementation, stimulants, second-generation antipsychotics) for major depressive disorder (MDD) often produce less-than-desired outcomes while carrying a potentially substantial safety and tolerability burden. The lack of clinically useful and individual-based biomarkers (eg, genetic, neurophysiological, imaging) is a major obstacle to enhancing treatment efficacy and/or decreasing associated adverse effects (AEs). While the discovery of such tools is being aggressively pursued and ultimately will facilitate a more precision-based choice of therapy, empirical strategies remain our primary approach.

In controlled trials, several nontraditional treatments used primarily as adjuncts to standard antidepressants have shown promise. These include “repurposed” (off-label) medications, herbal/nutraceuticals, anti-inflammatory/immune system therapies, device-based treatments, and other alternative approaches.

Importantly, some nontraditional treatments also demonstrate AEs (Table^1-16). With a careful consideration of the risk/benefit balance, this article reviews some of the better-studied treatment options for patients with treatment-resistant depression (TRD). In Part 1, we will examine off-label medications. In Part 2, we will review other nontraditional approaches to TRD, including herbal/nutraceuticals, anti-inflammatory/immune system therapies, device-based treatments, and other alternative approaches.

CP02009038_t1.PNG

We believe this review will help clinicians who need to formulate a different approach after their patient with depression is not helped by traditional first-, second-, and third-line treatments. The potential options discussed in Part 1 of this article are categorized based on their putative mechanism of action (MOA) for depression.

Serotonergic and noradrenergic strategies

Pimavanserin is FDA-approved for treatment of Parkinson’s psychosis. Its potential MOA as an adjunctive strategy for MDD may involve 5-HT2A antagonist and inverse agonist receptor activity, as well as lesser effects at the 5-HT2Creceptor.

A 2-stage, 5-week randomized controlled trial (RCT) (CLARITY; N = 207) found adjunctive pimavanserin (34 mg/d) produced a robust antidepressant effect vs placebo in patients whose depression did not respond to selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs).¹ Furthermore, a secondary analysis of the data suggested that pimavanserin also improved sleepiness (P < .0003) and daily functioning (P < .014) at Week 5.²

Unfortunately, two 6-week, Phase III RCTs (CLARITY-2 and -3; N = 298) did not find a statistically significant difference between active treatment and placebo. This was based on change in the primary outcome measure (Hamilton Depression Rating Scale-17 score) when adjunctive pimavanserin (34 mg/d) was added to an SSRI or SNRI in patients with TRD.³ There was, however, a significant difference favoring active treatment over placebo based on the Clinical Global Impression–Severity score.

Continue to: In these trials...

In these trials, pimavanserin was generally well-tolerated. The most common AEs were dry mouth, nausea, and headache. Pimavanserin has minimal activity at norepinephrine, dopamine, histamine, or acetylcholine receptors, thus avoiding AEs associated with these receptor interactions.

Given the mixed efficacy results of existing trials, further studies are needed to clarify this agent’s overall risk/benefit in the context of TRD.

Antihypertensive medications

Emerging data suggest that some beta-adrenergic blockers, angiotensin-inhibiting agents, and calcium antagonists are associated with a decreased incidence of depression. A large 2020 study (N = 3,747,190) used population-based Danish registries (2005 to 2015) to evaluate if any of the 41 most commonly prescribed antihypertensive medications were associated with the diagnosis of depressive disorder or use of antidepressants.⁴ These researchers found that enalapril, ramipril, amlodipine, propranolol, atenolol, bisoprolol, carvedilol (P < .001), and verapamil (P < .004) were strongly associated with a decreased risk of depression.⁴

Adverse effects across these different classes of antihypertensives are well characterized, can be substantial, and commonly are related to their impact on cardiovascular function (eg, hypotension). Clinically, these agents may be potential adjuncts for patients with TRD who need antihypertensive therapy. Their use and the choice of specific agent should only be determined in consultation with the patient’s primary care physician (PCP) or appropriate specialist.

Glutamatergic strategies

Ketamine is a dissociative anesthetic and analgesic. Its MOA for treating depression appears to occur primarily through antagonist activity at the N-methyl-D-aspartate ionotropic receptor of the glutamatergic system. There is preliminary evidence that its opioid receptor actions also may contribute to its antidepressant effect.⁵

Continue to: Many published studies...

Many published studies and reviews have described ketamine’s role for treating MDD. Several studies have reported that low-dose (0.5 mg/kg) IV ketamine infusions can rapidly attenuate severe episodes of MDD as well as associated suicidality. For example, a meta-analysis of 9 RCTs (N = 368) comparing ketamine to placebo for acute treatment of unipolar and bipolar depression reported superior therapeutic effects with active treatment at 24 hours, 72 hours, and 7 days.⁶ The response and remission rates for ketamine were 52% and 21% at 24 hours; 48% and 24% at 72 hours; and 40% and 26% at 7 days, respectively.⁶

The most commonly reported AEs during the 4 hours after ketamine infusion included⁷:

• drowsiness, dizziness, poor coordination
• blurred vision, feeling strange or unreal
• hemodynamic changes (approximately 33%)
• small but significant (P < .05) increases in psychotomimetic and dissociative symptoms.

Because some individuals use ketamine recreationally, this agent also carries the risk of abuse.

Research is ongoing on strategies for long-term maintenance ketamine treatment, and the results of both short- and long-term trials will require careful scrutiny to better assess this agent’s safety and tolerability. Clinicians should first consider esketamine—the S-enantiomer of ketamine—because an intranasal formulation of this agent is FDA-approved for treating patients with TRD or MDD with suicidality when administered in a Risk Evaluation and Mitigation Strategy–certified setting.

Cholinergic strategies

Scopolamine is a potent muscarinic receptor antagonist used to prevent nausea and vomiting caused by motion sickness or medications used during surgery. Its use for MDD is based on the theory that muscarinic receptors may be hypersensitive in mood disorders.

Continue to: Several double-blind RCTs...

Several double-blind RCTs of patients with unipolar or bipolar depression that used 3 pulsed IV infusions (4.0 mcg/kg) over 15 minutes found a rapid, robust antidepressant effect with scopolamine vs placebo.^8,9 The oral formulation might also be effective, but would not have a rapid onset.

Common adverse effects of scopolamine include agitation, dry mouth, urinary retention, and cognitive clouding. Given scopolamine’s substantial AE profile, it should be considered only for patients with TRD who could also benefit from the oral formulation for the medical indications noted above, should generally be avoided in older patients, and should be prescribed in consultation with the patient’s PCP.

Botulinum toxin. This neurotoxin inhibits acetylcholine release. It is used to treat disorders characterized by abnormal muscular contraction, such as strabismus, blepharospasm, and chronic pain syndromes. Its MOA for depression may involve its paralytic effects after injection into the glabella forehead muscle (based on the facial feedback hypothesis), as well as modulation of neurotransmitters implicated in the pathophysiology of depression.

In several small trials, injectable botulinum toxin type A (BTA) (29 units) demonstrated antidepressant effects. A recent review that considered 6 trials (N = 235; 4 of the 6 studies were RCTs, 3 of which were rated as high quality) concluded that BTA may be a promising treatment for MDD.¹⁰ Limitations of this review included lack of a priori hypotheses, small sample sizes, gender bias, and difficulty in blinding.

In clinical trials, the most common AEs included local irritation at the injection site and transient headache. This agent’s relatively mild AE profile and possible overlap when used for some of the medical indications noted above opens its potential use as an adjunct in patients with comorbid TRD.

Continue to: Endocrine strategies

Endocrine strategies

Mifepristone (RU486). This anti-glucocorticoid receptor antagonist is used as an abortifacient. Based on the theory that hyperactivity of the hypothalamic-pituitary-adrenal axis is implicated in the pathophysiology of MDD with psychotic features (psychotic depression), this agent has been studied as a treatment for this indication.

An analysis of 5 double-blind RCTs (N = 1,460) found that 7 days of mifepristone, 1,200 mg/d, was superior to placebo (P < .004) in reducing psychotic symptoms of depression.¹¹ Plasma concentrations ≥1,600 ng/mL may be required to maximize benefit.¹¹

Overall, this agent demonstrated a good safety profile in clinical trials, with treatment-emergent AEs reported in 556 (66.7%) patients who received mifepristone vs 386 (61.6%) patients who received placebo.¹¹ Common AEs included gastrointestinal (GI) symptoms, headache, and dizziness. However, 3 deaths occurred: 2 patients who received mifepristone and 1 patient who received placebo. Given this potential for a fatal outcome, clinicians should first consider prescribing an adjunctive antipsychotic agent or electroconvulsive therapy.

Estrogens. These hormones are important for sexual and reproductive development and are used to treat various sexual/reproductive disorders, primarily in women. Their role in treating depression is based on the observation that perimenopause is accompanied by an increased risk of new and recurrent depression coincident with declining ovarian function.

Evidence supports the antidepressant efficacy of transdermal estradiol plus progesterone for perimenopausal depression, but not for postmenopausal depression.^12-14 However, estrogens carry significant risks that must be carefully considered in relationship to their potential benefits. These risks include:

• vaginal bleeding, dysmenorrhea
• fibroid enlargement
• galactorrhea
• ovarian cancer, endometrial cancer, breast cancer
• deep vein thrombosis, pulmonary embolism
• hypertension, chest pain, myocardial infarction, stroke.

Continue to: The use of estrogens...

The use of estrogens as an adjunctive therapy for women with treatment-resistant perimenopausal depression should only be undertaken when standard strategies have failed, and in consultation with an endocrine specialist who can monitor for potentially serious AEs.

Opioid medications

Buprenorphine is used to treat opioid use disorder (OUD) as well as acute and chronic pain. The opioid system is involved in the regulation of mood and may be an appropriate target for novel antidepressants. The use of buprenorphine in combination with samidorphan (a preferential mu-opioid receptor antagonist) has shown initial promise for TRD while minimizing abuse potential.

Although earlier results were mixed, a pooled analysis of 2 recent large RCTs (N = 760) of patients with MDD who had not responded to antidepressants reported greater reduction in Montgomery-Åsberg Depression Rating Scale scores from baseline for active treatment (buprenorphine/samidorphan; 2 mg/2 mg) vs placebo at multiple timepoints, including end of treatment (-1.8; P < .010).¹⁵

The most common AEs included nausea, constipation, dizziness, vomiting, somnolence, fatigue, and sedation. There was minimal evidence of abuse, dependence, or opioid withdrawal. Due to the opioid crisis in the United States, the resulting relaxation of regulations regarding prescribing buprenorphine, and the high rates of depression among patients with OUD, buprenorphine/samidorphan, which is an investigational agent that is not FDA-approved, may be particularly helpful for patients with OUD who also experience comorbid TRD.

Antioxidant agents

N-acetylcysteine (NAC) is an amino acid that can treat acetaminophen toxicity and moderate hepatic damage by increasing glutathione levels. Glutathione is also the primary antioxidant in the CNS. NAC may protect against oxidative stress, chelate heavy metals, reduce inflammation, protect against mitochondrial dysfunction, inhibit apoptosis, and enhance neurogenesis, all potential pathophysiological processes that may contribute to depression.¹⁶

Continue to: A systematic review...

A systematic review and meta-analysis of 5 RCTs (N = 574) considered patients with various depression diagnoses who were randomized to adjunctive NAC, 1,000 mg twice a day, or placebo. Over 12 to 24 weeks, there was a significantly greater improvement in mood symptoms and functionality with NAC vs placebo.¹⁶

Overall, NAC was well-tolerated. The most common AEs were GI symptoms, musculoskeletal complaints, decreased energy, and headache. While NAC has been touted as a potential adjunct therapy for several psychiatric disorders, including TRD, the evidence for benefit remains limited. Given its favorable AE profile, however, and over-the-counter availability, it remains an option for select patients. It is important to ask patients if they are already taking NAC.

Options beyond off-label medications

There are a multitude of options available for addressing TRD. Many FDA-approved medications are repurposed and prescribed off-label for other indications when the risk/benefit balance is favorable. In Part 1 of this article, we reviewed several off-label medications that have supportive controlled data for treating TRD. In Part 2, we will review other nontraditional therapies for TRD, including herbal/nutraceuticals, anti-inflammatory/immune system therapies, device-based treatments, and other alternative approaches.

Bottom Line

Off-label medications that may offer benefit for patients with treatment-resistant depression (TRD) include pimavanserin, antihypertensive agents, ketamine, scopolamine, botulinum toxin, mifepristone, estrogens, buprenorphine, and N-acetylcysteine. Although some evidence supports use of these agents as adjuncts for TRD, an individualized risk/benefit analysis is required.

Related Resource

• Joshi KG, Frierson RL. Off-label prescribing: How to limit your liability. Current Psychiatry. 2020;19(9):12,39.

Drug Brand Names

Amlodipine • Katerzia, Norvasc
Atenolol • Tenormin
Bisoprolol • Zebeta
Buprenorphine • Sublocade, Subutex
Carvedilol • Coreg
Enalapril • Vasotec
Esketamine • Spravato
Estradiol transdermal • Estraderm
Ketamine • Ketalar
Mifepristone • Mifeprex
Pimavanserin • Nuplazid
Progesterone • Prometrium
Propranolol • Inderal
Ramipril • Altace
Verapamil • Calan, Verelan

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Presently, FDA-approved first-line treatments and standard adjunctive strategies (eg, lithium, thyroid supplementation, stimulants, second-generation antipsychotics) for major depressive disorder (MDD) often produce less-than-desired outcomes while carrying a potentially substantial safety and tolerability burden. The lack of clinically useful and individual-based biomarkers (eg, genetic, neurophysiological, imaging) is a major obstacle to enhancing treatment efficacy and/or decreasing associated adverse effects (AEs). While the discovery of such tools is being aggressively pursued and ultimately will facilitate a more precision-based choice of therapy, empirical strategies remain our primary approach.

In controlled trials, several nontraditional treatments used primarily as adjuncts to standard antidepressants have shown promise. These include “repurposed” (off-label) medications, herbal/nutraceuticals, anti-inflammatory/immune system therapies, device-based treatments, and other alternative approaches.

Importantly, some nontraditional treatments also demonstrate AEs (Table^1-16). With a careful consideration of the risk/benefit balance, this article reviews some of the better-studied treatment options for patients with treatment-resistant depression (TRD). In Part 1, we will examine off-label medications. In Part 2, we will review other nontraditional approaches to TRD, including herbal/nutraceuticals, anti-inflammatory/immune system therapies, device-based treatments, and other alternative approaches.

CP02009038_t1.PNG

We believe this review will help clinicians who need to formulate a different approach after their patient with depression is not helped by traditional first-, second-, and third-line treatments. The potential options discussed in Part 1 of this article are categorized based on their putative mechanism of action (MOA) for depression.

Serotonergic and noradrenergic strategies

Pimavanserin is FDA-approved for treatment of Parkinson’s psychosis. Its potential MOA as an adjunctive strategy for MDD may involve 5-HT2A antagonist and inverse agonist receptor activity, as well as lesser effects at the 5-HT2Creceptor.

A 2-stage, 5-week randomized controlled trial (RCT) (CLARITY; N = 207) found adjunctive pimavanserin (34 mg/d) produced a robust antidepressant effect vs placebo in patients whose depression did not respond to selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs).¹ Furthermore, a secondary analysis of the data suggested that pimavanserin also improved sleepiness (P < .0003) and daily functioning (P < .014) at Week 5.²

Unfortunately, two 6-week, Phase III RCTs (CLARITY-2 and -3; N = 298) did not find a statistically significant difference between active treatment and placebo. This was based on change in the primary outcome measure (Hamilton Depression Rating Scale-17 score) when adjunctive pimavanserin (34 mg/d) was added to an SSRI or SNRI in patients with TRD.³ There was, however, a significant difference favoring active treatment over placebo based on the Clinical Global Impression–Severity score.

Continue to: In these trials...

In these trials, pimavanserin was generally well-tolerated. The most common AEs were dry mouth, nausea, and headache. Pimavanserin has minimal activity at norepinephrine, dopamine, histamine, or acetylcholine receptors, thus avoiding AEs associated with these receptor interactions.

Given the mixed efficacy results of existing trials, further studies are needed to clarify this agent’s overall risk/benefit in the context of TRD.

Antihypertensive medications

Emerging data suggest that some beta-adrenergic blockers, angiotensin-inhibiting agents, and calcium antagonists are associated with a decreased incidence of depression. A large 2020 study (N = 3,747,190) used population-based Danish registries (2005 to 2015) to evaluate if any of the 41 most commonly prescribed antihypertensive medications were associated with the diagnosis of depressive disorder or use of antidepressants.⁴ These researchers found that enalapril, ramipril, amlodipine, propranolol, atenolol, bisoprolol, carvedilol (P < .001), and verapamil (P < .004) were strongly associated with a decreased risk of depression.⁴

Adverse effects across these different classes of antihypertensives are well characterized, can be substantial, and commonly are related to their impact on cardiovascular function (eg, hypotension). Clinically, these agents may be potential adjuncts for patients with TRD who need antihypertensive therapy. Their use and the choice of specific agent should only be determined in consultation with the patient’s primary care physician (PCP) or appropriate specialist.

Glutamatergic strategies

Ketamine is a dissociative anesthetic and analgesic. Its MOA for treating depression appears to occur primarily through antagonist activity at the N-methyl-D-aspartate ionotropic receptor of the glutamatergic system. There is preliminary evidence that its opioid receptor actions also may contribute to its antidepressant effect.⁵

Continue to: Many published studies...

Many published studies and reviews have described ketamine’s role for treating MDD. Several studies have reported that low-dose (0.5 mg/kg) IV ketamine infusions can rapidly attenuate severe episodes of MDD as well as associated suicidality. For example, a meta-analysis of 9 RCTs (N = 368) comparing ketamine to placebo for acute treatment of unipolar and bipolar depression reported superior therapeutic effects with active treatment at 24 hours, 72 hours, and 7 days.⁶ The response and remission rates for ketamine were 52% and 21% at 24 hours; 48% and 24% at 72 hours; and 40% and 26% at 7 days, respectively.⁶

The most commonly reported AEs during the 4 hours after ketamine infusion included⁷:

• drowsiness, dizziness, poor coordination
• blurred vision, feeling strange or unreal
• hemodynamic changes (approximately 33%)
• small but significant (P < .05) increases in psychotomimetic and dissociative symptoms.

Because some individuals use ketamine recreationally, this agent also carries the risk of abuse.

Research is ongoing on strategies for long-term maintenance ketamine treatment, and the results of both short- and long-term trials will require careful scrutiny to better assess this agent’s safety and tolerability. Clinicians should first consider esketamine—the S-enantiomer of ketamine—because an intranasal formulation of this agent is FDA-approved for treating patients with TRD or MDD with suicidality when administered in a Risk Evaluation and Mitigation Strategy–certified setting.

Cholinergic strategies

Scopolamine is a potent muscarinic receptor antagonist used to prevent nausea and vomiting caused by motion sickness or medications used during surgery. Its use for MDD is based on the theory that muscarinic receptors may be hypersensitive in mood disorders.

Continue to: Several double-blind RCTs...

Several double-blind RCTs of patients with unipolar or bipolar depression that used 3 pulsed IV infusions (4.0 mcg/kg) over 15 minutes found a rapid, robust antidepressant effect with scopolamine vs placebo.^8,9 The oral formulation might also be effective, but would not have a rapid onset.

Common adverse effects of scopolamine include agitation, dry mouth, urinary retention, and cognitive clouding. Given scopolamine’s substantial AE profile, it should be considered only for patients with TRD who could also benefit from the oral formulation for the medical indications noted above, should generally be avoided in older patients, and should be prescribed in consultation with the patient’s PCP.

Botulinum toxin. This neurotoxin inhibits acetylcholine release. It is used to treat disorders characterized by abnormal muscular contraction, such as strabismus, blepharospasm, and chronic pain syndromes. Its MOA for depression may involve its paralytic effects after injection into the glabella forehead muscle (based on the facial feedback hypothesis), as well as modulation of neurotransmitters implicated in the pathophysiology of depression.

In several small trials, injectable botulinum toxin type A (BTA) (29 units) demonstrated antidepressant effects. A recent review that considered 6 trials (N = 235; 4 of the 6 studies were RCTs, 3 of which were rated as high quality) concluded that BTA may be a promising treatment for MDD.¹⁰ Limitations of this review included lack of a priori hypotheses, small sample sizes, gender bias, and difficulty in blinding.

In clinical trials, the most common AEs included local irritation at the injection site and transient headache. This agent’s relatively mild AE profile and possible overlap when used for some of the medical indications noted above opens its potential use as an adjunct in patients with comorbid TRD.

Continue to: Endocrine strategies

Endocrine strategies

Mifepristone (RU486). This anti-glucocorticoid receptor antagonist is used as an abortifacient. Based on the theory that hyperactivity of the hypothalamic-pituitary-adrenal axis is implicated in the pathophysiology of MDD with psychotic features (psychotic depression), this agent has been studied as a treatment for this indication.

An analysis of 5 double-blind RCTs (N = 1,460) found that 7 days of mifepristone, 1,200 mg/d, was superior to placebo (P < .004) in reducing psychotic symptoms of depression.¹¹ Plasma concentrations ≥1,600 ng/mL may be required to maximize benefit.¹¹

Overall, this agent demonstrated a good safety profile in clinical trials, with treatment-emergent AEs reported in 556 (66.7%) patients who received mifepristone vs 386 (61.6%) patients who received placebo.¹¹ Common AEs included gastrointestinal (GI) symptoms, headache, and dizziness. However, 3 deaths occurred: 2 patients who received mifepristone and 1 patient who received placebo. Given this potential for a fatal outcome, clinicians should first consider prescribing an adjunctive antipsychotic agent or electroconvulsive therapy.

Estrogens. These hormones are important for sexual and reproductive development and are used to treat various sexual/reproductive disorders, primarily in women. Their role in treating depression is based on the observation that perimenopause is accompanied by an increased risk of new and recurrent depression coincident with declining ovarian function.

Evidence supports the antidepressant efficacy of transdermal estradiol plus progesterone for perimenopausal depression, but not for postmenopausal depression.^12-14 However, estrogens carry significant risks that must be carefully considered in relationship to their potential benefits. These risks include:

• vaginal bleeding, dysmenorrhea
• fibroid enlargement
• galactorrhea
• ovarian cancer, endometrial cancer, breast cancer
• deep vein thrombosis, pulmonary embolism
• hypertension, chest pain, myocardial infarction, stroke.

Continue to: The use of estrogens...

The use of estrogens as an adjunctive therapy for women with treatment-resistant perimenopausal depression should only be undertaken when standard strategies have failed, and in consultation with an endocrine specialist who can monitor for potentially serious AEs.

Opioid medications

Buprenorphine is used to treat opioid use disorder (OUD) as well as acute and chronic pain. The opioid system is involved in the regulation of mood and may be an appropriate target for novel antidepressants. The use of buprenorphine in combination with samidorphan (a preferential mu-opioid receptor antagonist) has shown initial promise for TRD while minimizing abuse potential.

Although earlier results were mixed, a pooled analysis of 2 recent large RCTs (N = 760) of patients with MDD who had not responded to antidepressants reported greater reduction in Montgomery-Åsberg Depression Rating Scale scores from baseline for active treatment (buprenorphine/samidorphan; 2 mg/2 mg) vs placebo at multiple timepoints, including end of treatment (-1.8; P < .010).¹⁵

The most common AEs included nausea, constipation, dizziness, vomiting, somnolence, fatigue, and sedation. There was minimal evidence of abuse, dependence, or opioid withdrawal. Due to the opioid crisis in the United States, the resulting relaxation of regulations regarding prescribing buprenorphine, and the high rates of depression among patients with OUD, buprenorphine/samidorphan, which is an investigational agent that is not FDA-approved, may be particularly helpful for patients with OUD who also experience comorbid TRD.

Antioxidant agents

N-acetylcysteine (NAC) is an amino acid that can treat acetaminophen toxicity and moderate hepatic damage by increasing glutathione levels. Glutathione is also the primary antioxidant in the CNS. NAC may protect against oxidative stress, chelate heavy metals, reduce inflammation, protect against mitochondrial dysfunction, inhibit apoptosis, and enhance neurogenesis, all potential pathophysiological processes that may contribute to depression.¹⁶

Continue to: A systematic review...

A systematic review and meta-analysis of 5 RCTs (N = 574) considered patients with various depression diagnoses who were randomized to adjunctive NAC, 1,000 mg twice a day, or placebo. Over 12 to 24 weeks, there was a significantly greater improvement in mood symptoms and functionality with NAC vs placebo.¹⁶

Overall, NAC was well-tolerated. The most common AEs were GI symptoms, musculoskeletal complaints, decreased energy, and headache. While NAC has been touted as a potential adjunct therapy for several psychiatric disorders, including TRD, the evidence for benefit remains limited. Given its favorable AE profile, however, and over-the-counter availability, it remains an option for select patients. It is important to ask patients if they are already taking NAC.

Options beyond off-label medications

There are a multitude of options available for addressing TRD. Many FDA-approved medications are repurposed and prescribed off-label for other indications when the risk/benefit balance is favorable. In Part 1 of this article, we reviewed several off-label medications that have supportive controlled data for treating TRD. In Part 2, we will review other nontraditional therapies for TRD, including herbal/nutraceuticals, anti-inflammatory/immune system therapies, device-based treatments, and other alternative approaches.

Bottom Line

Off-label medications that may offer benefit for patients with treatment-resistant depression (TRD) include pimavanserin, antihypertensive agents, ketamine, scopolamine, botulinum toxin, mifepristone, estrogens, buprenorphine, and N-acetylcysteine. Although some evidence supports use of these agents as adjuncts for TRD, an individualized risk/benefit analysis is required.

Related Resource

• Joshi KG, Frierson RL. Off-label prescribing: How to limit your liability. Current Psychiatry. 2020;19(9):12,39.

Drug Brand Names

Amlodipine • Katerzia, Norvasc
Atenolol • Tenormin
Bisoprolol • Zebeta
Buprenorphine • Sublocade, Subutex
Carvedilol • Coreg
Enalapril • Vasotec
Esketamine • Spravato
Estradiol transdermal • Estraderm
Ketamine • Ketalar
Mifepristone • Mifeprex
Pimavanserin • Nuplazid
Progesterone • Prometrium
Propranolol • Inderal
Ramipril • Altace
Verapamil • Calan, Verelan

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Therapeutic neuromodulation takes advantage of the brain’s electrochemical makeup. This allows for treatment devices that modulate neurocircuits relevant to behaviors disrupted in disorders such as major depressive disorder (MDD) (eg, sleep quality, appetite, cognitive, and executive functions). The default mode network (comprised of structures such as the medial prefrontal cortex [MPFC], the posterior cingulate cortex, the hippocampus, and their functional connectivity) serves as a prime example of circuitry that can be targeted by this approach.¹

For 80 years, electroconvulsive therapy (ECT) has been an important neuromodulation option for patients with more severe illness. Recently, additional neuromodulatory approaches have been FDA-cleared, including transcranial magnetic stimulation (TMS), vagus nerve stimulation (VNS), and deep brain stimulation (DBS). Another approach, transcranial direct current stimulation (tDCS), has been extensively studied for its potential clinical utility but is not FDA-cleared. The Table provides descriptions of these therapies.

CP01803010_t1.PNG

An evolving therapeutic option

While primarily studied as a monotherapy for MDD, in clinical practice TMS (Box) is typically used as an adjunct to medication and psychotherapy.^2,3 In this context, it has demonstrated efficacy for more difficult-to-treat mood disorders with an excellent safety and tolerability profile whether used with or without medication.^4-6

To further improve the efficiency and efficacy of TMS while maintaining its safety and tolerability, researchers and clinicians have been exploring a few initiatives.

Box

Altered treatment parameters

One initiative is assessing the feasibility of altering various treatment parameters, such as the total number of treatment sessions (30 to 60 sessions); the frequency of sessions (eg, more than once daily); the total number of magnetic pulses per session (eg, >3,000); the stimulation coil localization (eg, left vs right dorsal lateral prefrontal cortex [DLPFC]; MPFC; and various methods to determine optimal coil placement (eg, EEG F3 coordinate or MRI-guided neuro-navigational methods). Such refinements offer the potential for enhanced efficacy, shorter treatment sessions, and/or improved tolerability. For example, lower frequency right DLPFC stimulations (eg, 1 Hz) can decrease the risk of seizures and improve overall tolerability. While this has not been studied as extensively as higher frequency left DLPFC stimulations (eg, 5 to 20 Hz), existing evidence supports similar efficacy between these 2 approaches.⁷

Theta burst stimulation. Some TMS devices can be adapted to deliver theta burst stimulation (TBS). This produces trains of triple, 50 Hz, pulsed bursts (usually with 200 ms inter-burst intervals occurring at a rate of 5 Hz; at 80% MT) to model naturally occurring theta rhythms. These bursts can be administered in stimulation protocols using intermittent TBS (iTBS) (eg, 10 bursts of triplets over 2 seconds every 10 seconds; 30 pulses per burst; for approximately 3 minutes; totaling 600 pulses) or continuous TBS (cTBS) bursts given in an uninterrupted train (eg, 40 seconds, 600 pulses). Evidence indicates these protocols facilitate long-term potentiation (ie, iTBS) and long-term depression (ie, cTBS), which in turn can modulate synaptic plasticity.

Continue to: While some clinicians are using...

While some clinicians are using TBS off-label, a recent non-inferiority trial (N = 395) reported similar efficacy and safety comparing standard 10 Hz TMS to an iTBS protocol at 120% of resting motor threshold (both over the left DLPFC).⁸ This has led to FDA clearance of the TMS device adapted to provide iTBS in this trial.⁸

From a more practical perspective, TBS has the potential to reduce the number of pulses (eg, 600 vs 3,000) and the total number of sessions required, as well as the duration of treatment sessions (eg, 37.5 minutes to <5 minutes). This can accelerate the time to response and decrease patient and staff commitment, with resulting cost savings.⁹ Despite this recent progress, ongoing research still needs to clarify issues such as the risk/benefit profile, particularly in younger and older populations, as well as assessment of duration of initial benefit and appropriate maintenance strategies.

New devices

Another initiative is the development of alternative TMS equipment. For example, newer coil designs with enhanced cooling ability allow for a substantial decrease in the required inter-train interval duration between stimulation trains, thus shortening the total session duration by approximately 50% (eg, from 37.5 to 19 minutes). The use of different coil arrays (eg, the H-coil capable of deeper vs surface stimulation) may allow for more direct stimulation of relevant neurocircuitry (eg, cingulate cortex), possibly improving efficacy and shortening time to onset of benefit. However, in head-to-head comparisons with single-coil devices, enhanced efficacy for depression has not been clearly demonstrated. One caveat is that the increase in depth of magnetic field penetration results in a loss of focality, resulting in the stimulation of larger brain areas. This might increase the risk of adverse effects such as seizures.

Increasing durability of effect

Because high relapse and recurrence rates compromise the initial benefit of any antidepressant therapy, appropriate maintenance strategies are essential. Several studies have evaluated strategies to maintain the acute benefit of TMS for treatment-resistant depression.

One was a 6-month, open-label TMS durability of effect trial for acute responders (n = 99) in the pivotal registration study.⁵ During this study, all participants were given antidepressant medication monotherapy. In addition, with early indication of relapse, patients received a reintroduction of TMS sessions (32/99 patients; mean number of sessions = 14.3). With this protocol, approximately 84% re-achieved their response status. The overall relapse rate was approximately 13%.⁵

Continue to: In a 1-year naturalistic study...

In a 1-year naturalistic study, 63% of patients (75/120) who met response or remission criteria after an acute course of TMS still met response criteria after 12 months. These patients received clinician-determined maintenance treatment that included reintroduction of TMS when indicated.³

In a prospective, 12-month, multisite, randomized pilot study, 67 patients with treatment-resistant MDD underwent an antidepressant medication washout and then received 30 sessions of TMS monotherapy.¹⁰ Those who met criteria for improvement (n = 49) were then randomized to once-monthly TMS or observation only. All patients remained medication-free but could receive TMS re-introduction if they deteriorated. At the end of the study, both groups demonstrated comparable outcomes, with a trend to a longer time before relapse among participants who received once-monthly TMS. Although these results are preliminary, they suggest that some patients could be treated both acutely and then maintained with TMS alone.

Re-introducing TMS in patients who show early signs of relapse after having an initial response achieves rates of sustained improvement that compare favorably with those of other strategies used to manage patients with treatment-resistant depression.

TMS vs ECT

The question often arises as to whether TMS is a viable alternate treatment to ECT. I believe the answer is unequivocally yes and no. By this, I mean some patients who in the past only had ECT as their next option when medications and psychotherapy were insufficient may now consider TMS. In support, there is evidence of comparable efficacy between TMS and ECT in a subgroup of patients who were considered clinically appropriate for ECT.^11-13

How to best identify this group remains unclear, but investigators are exploring predictive biomarkers. For example, a large study (N = 1,188), with functional magnetic resonance imaging (fMRI) reported that depressed patients could be divided into 4 neurophysiological “biotypes” based on different patterns of aberrant connectivity in limbic and fronto-striatal networks.¹⁴ The authors further noted that such distinctions were helpful in predicting response in a subgroup of patients (n = 154) who received TMS.

Continue to: For now...

For now, experience indicates certain clinical factors may provide some guidance. Patients are usually better served by ECT if they:

• have depressive episodes of longer duration (eg, >3 years)
• have a high risk of suicide
• have psychotic or catatonic features associated with their depression
• have difficulty maintaining their physical well-being
• have bipolar depression.

Although existing evidence supports a possible benefit with TMS for bipolar depression (used in combination with a mood stabilizer), the lack of a definitive trial (precluding FDA clearance for this indication) and the lack of insurance coverage both limit the routine use of TMS for this indication.¹⁵

One potential advantage of TMS over ECT is a lower cost.¹³ Transcranial magnetic stimulation also may make it possible to achieve similar efficacy as ECT with fewer cognitive adverse effects when used in combination with ECT to reduce the number of acute ECT treatments required or as part of a maintenance strategy after a patient experiences an acute response to ECT.¹³

Magnetic seizure therapy (MST) vs ECT. An experimental treatment, MST uses a TMS device capable of producing more intense magnetic fields sufficient to induce a seizure.¹⁶ The advantage of MST over ECT-induced seizures is better control of intra-cerebral current path and density, thus avoiding deeper cortical areas associated with memory (eg, hippocampus) and minimizing cognitive adverse effects. As with ECT, however, anesthesia and muscle relaxation are required. Presently, MST remains investigational.

Other potential indications

In addition to MDD, TMS is also being studied as a potential treatment for other neuropsychiatric disorders.

Continue to: Obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD). A recent double-blind study that evaluated a deep TMS (DTMS) device reported a significantly better outcome based on the Yale-Brown Obsessive-Compulsive Scale score with active high-frequency (20 Hz) DTMS (n = 18) vs a sham control (n = 15).¹⁷ The initial benefit persisted up to 1 month after the end of treatment. The authors speculated that this benefit may be due to direct modulation of the anterior cingulate cortex. These results led to the first FDA clearance of a deep TMS device for treating OCD.

Cognition. Because TMS does not require a seizure to produce its antidepressant effect and does not require anesthesia, the risk of neurocognitive disruption is low. In fact, evidence suggests TMS may have beneficial cognitive effects.¹⁸

In an effort to take advantage of this benefit, researchers have explored providing psychoeducation and psychotherapy sessions (eg, behavioral activation) during TMS treatments (“online”).^19,20 The rationale is that neurocircuitry subserving various cognitive functions may be in a heightened state of receptivity during a TMS treatment, which would allow patients to assimilate and better utilize the therapeutic information provided.^19,20

Researchers are also looking at the use of TMS to treat patients with mild cognitive impairment or early dementia. These patients often experience comorbid depression, and TMS could potentially improve memory via both its pro-cognitive and antidepressant effects.¹ The lack of effective treatments for dementia supports pursuing TMS as a therapeutic option for these patients.

Other neuropsychiatric disorders. In addition to early-onset cognitive problems, other neurologic indications with promising data for TMS include chronic pain syndromes, Parkinson’s disease, tinnitus, and migraine headaches (a hand-held FDA-cleared device is now available for treating migraines). In addition to OCD and bipolar depression, other psychiatric indications with promising data include schizophrenia (eg, refractory auditory hallucinations, negative symptoms), posttraumatic stress disorder, and various addictive disorders.²¹ Because results have been mixed for most of these disorders, definitive trials are needed to clearly characterize the potential role of TMS.

Continue to: An ongoing evolution

Neuromodulation is undergoing a renaissance spurred on by the need for more effective treatments to manage some of our most challenging illnesses. Transcranial magnetic stimulation and other forms of therapeutic neuromodulation are welcome additions for managing treatment-resistant depression, OCD, and possibly other disorders. But perhaps their greatest value is as a bellwether for what’s to come. In addition to the ongoing refinements to existing neuro­modulation devices, newer modulation approaches (eg, temporal interference stimulation) and the search for reliable biomarkers may dramatically expand and enhance our clinical options.^14,22

Bottom Line

Transcranial magnetic stimulation (TMS) continues to evolve as a nonpharmacologic treatment for mood disorders, obsessive-compulsive disorder, and potentially for other indications. Recent developments, including altered treatment parameters, new devices, and strategies for increasing the durability of antidepressant effects, have enhanced the benefits of TMS.

Related Resources

• Ziemann U. Thirty years of transcranial magnetic stimulation: where do we stand? Exp Brain Res. 2017;235(4):973-984.
• Janicak PG, Sackett V, Kudrna K, et al. Transcranial magnetic stimulation for the treatment of major depression: an update on recent advances. Current Psychiatry. 2016:15(6):49-56.

[embed:render:related:node:206992]

Therapeutic neuromodulation takes advantage of the brain’s electrochemical makeup. This allows for treatment devices that modulate neurocircuits relevant to behaviors disrupted in disorders such as major depressive disorder (MDD) (eg, sleep quality, appetite, cognitive, and executive functions). The default mode network (comprised of structures such as the medial prefrontal cortex [MPFC], the posterior cingulate cortex, the hippocampus, and their functional connectivity) serves as a prime example of circuitry that can be targeted by this approach.¹

For 80 years, electroconvulsive therapy (ECT) has been an important neuromodulation option for patients with more severe illness. Recently, additional neuromodulatory approaches have been FDA-cleared, including transcranial magnetic stimulation (TMS), vagus nerve stimulation (VNS), and deep brain stimulation (DBS). Another approach, transcranial direct current stimulation (tDCS), has been extensively studied for its potential clinical utility but is not FDA-cleared. The Table provides descriptions of these therapies.

CP01803010_t1.PNG

An evolving therapeutic option

While primarily studied as a monotherapy for MDD, in clinical practice TMS (Box) is typically used as an adjunct to medication and psychotherapy.^2,3 In this context, it has demonstrated efficacy for more difficult-to-treat mood disorders with an excellent safety and tolerability profile whether used with or without medication.^4-6

To further improve the efficiency and efficacy of TMS while maintaining its safety and tolerability, researchers and clinicians have been exploring a few initiatives.

Box

Altered treatment parameters

One initiative is assessing the feasibility of altering various treatment parameters, such as the total number of treatment sessions (30 to 60 sessions); the frequency of sessions (eg, more than once daily); the total number of magnetic pulses per session (eg, >3,000); the stimulation coil localization (eg, left vs right dorsal lateral prefrontal cortex [DLPFC]; MPFC; and various methods to determine optimal coil placement (eg, EEG F3 coordinate or MRI-guided neuro-navigational methods). Such refinements offer the potential for enhanced efficacy, shorter treatment sessions, and/or improved tolerability. For example, lower frequency right DLPFC stimulations (eg, 1 Hz) can decrease the risk of seizures and improve overall tolerability. While this has not been studied as extensively as higher frequency left DLPFC stimulations (eg, 5 to 20 Hz), existing evidence supports similar efficacy between these 2 approaches.⁷

Theta burst stimulation. Some TMS devices can be adapted to deliver theta burst stimulation (TBS). This produces trains of triple, 50 Hz, pulsed bursts (usually with 200 ms inter-burst intervals occurring at a rate of 5 Hz; at 80% MT) to model naturally occurring theta rhythms. These bursts can be administered in stimulation protocols using intermittent TBS (iTBS) (eg, 10 bursts of triplets over 2 seconds every 10 seconds; 30 pulses per burst; for approximately 3 minutes; totaling 600 pulses) or continuous TBS (cTBS) bursts given in an uninterrupted train (eg, 40 seconds, 600 pulses). Evidence indicates these protocols facilitate long-term potentiation (ie, iTBS) and long-term depression (ie, cTBS), which in turn can modulate synaptic plasticity.

Continue to: While some clinicians are using...

While some clinicians are using TBS off-label, a recent non-inferiority trial (N = 395) reported similar efficacy and safety comparing standard 10 Hz TMS to an iTBS protocol at 120% of resting motor threshold (both over the left DLPFC).⁸ This has led to FDA clearance of the TMS device adapted to provide iTBS in this trial.⁸

From a more practical perspective, TBS has the potential to reduce the number of pulses (eg, 600 vs 3,000) and the total number of sessions required, as well as the duration of treatment sessions (eg, 37.5 minutes to <5 minutes). This can accelerate the time to response and decrease patient and staff commitment, with resulting cost savings.⁹ Despite this recent progress, ongoing research still needs to clarify issues such as the risk/benefit profile, particularly in younger and older populations, as well as assessment of duration of initial benefit and appropriate maintenance strategies.

New devices

Another initiative is the development of alternative TMS equipment. For example, newer coil designs with enhanced cooling ability allow for a substantial decrease in the required inter-train interval duration between stimulation trains, thus shortening the total session duration by approximately 50% (eg, from 37.5 to 19 minutes). The use of different coil arrays (eg, the H-coil capable of deeper vs surface stimulation) may allow for more direct stimulation of relevant neurocircuitry (eg, cingulate cortex), possibly improving efficacy and shortening time to onset of benefit. However, in head-to-head comparisons with single-coil devices, enhanced efficacy for depression has not been clearly demonstrated. One caveat is that the increase in depth of magnetic field penetration results in a loss of focality, resulting in the stimulation of larger brain areas. This might increase the risk of adverse effects such as seizures.

Increasing durability of effect

Because high relapse and recurrence rates compromise the initial benefit of any antidepressant therapy, appropriate maintenance strategies are essential. Several studies have evaluated strategies to maintain the acute benefit of TMS for treatment-resistant depression.

One was a 6-month, open-label TMS durability of effect trial for acute responders (n = 99) in the pivotal registration study.⁵ During this study, all participants were given antidepressant medication monotherapy. In addition, with early indication of relapse, patients received a reintroduction of TMS sessions (32/99 patients; mean number of sessions = 14.3). With this protocol, approximately 84% re-achieved their response status. The overall relapse rate was approximately 13%.⁵

Continue to: In a 1-year naturalistic study...

In a 1-year naturalistic study, 63% of patients (75/120) who met response or remission criteria after an acute course of TMS still met response criteria after 12 months. These patients received clinician-determined maintenance treatment that included reintroduction of TMS when indicated.³

In a prospective, 12-month, multisite, randomized pilot study, 67 patients with treatment-resistant MDD underwent an antidepressant medication washout and then received 30 sessions of TMS monotherapy.¹⁰ Those who met criteria for improvement (n = 49) were then randomized to once-monthly TMS or observation only. All patients remained medication-free but could receive TMS re-introduction if they deteriorated. At the end of the study, both groups demonstrated comparable outcomes, with a trend to a longer time before relapse among participants who received once-monthly TMS. Although these results are preliminary, they suggest that some patients could be treated both acutely and then maintained with TMS alone.

Re-introducing TMS in patients who show early signs of relapse after having an initial response achieves rates of sustained improvement that compare favorably with those of other strategies used to manage patients with treatment-resistant depression.

TMS vs ECT

The question often arises as to whether TMS is a viable alternate treatment to ECT. I believe the answer is unequivocally yes and no. By this, I mean some patients who in the past only had ECT as their next option when medications and psychotherapy were insufficient may now consider TMS. In support, there is evidence of comparable efficacy between TMS and ECT in a subgroup of patients who were considered clinically appropriate for ECT.^11-13

How to best identify this group remains unclear, but investigators are exploring predictive biomarkers. For example, a large study (N = 1,188), with functional magnetic resonance imaging (fMRI) reported that depressed patients could be divided into 4 neurophysiological “biotypes” based on different patterns of aberrant connectivity in limbic and fronto-striatal networks.¹⁴ The authors further noted that such distinctions were helpful in predicting response in a subgroup of patients (n = 154) who received TMS.

Continue to: For now...

For now, experience indicates certain clinical factors may provide some guidance. Patients are usually better served by ECT if they:

• have depressive episodes of longer duration (eg, >3 years)
• have a high risk of suicide
• have psychotic or catatonic features associated with their depression
• have difficulty maintaining their physical well-being
• have bipolar depression.

Although existing evidence supports a possible benefit with TMS for bipolar depression (used in combination with a mood stabilizer), the lack of a definitive trial (precluding FDA clearance for this indication) and the lack of insurance coverage both limit the routine use of TMS for this indication.¹⁵

One potential advantage of TMS over ECT is a lower cost.¹³ Transcranial magnetic stimulation also may make it possible to achieve similar efficacy as ECT with fewer cognitive adverse effects when used in combination with ECT to reduce the number of acute ECT treatments required or as part of a maintenance strategy after a patient experiences an acute response to ECT.¹³

Magnetic seizure therapy (MST) vs ECT. An experimental treatment, MST uses a TMS device capable of producing more intense magnetic fields sufficient to induce a seizure.¹⁶ The advantage of MST over ECT-induced seizures is better control of intra-cerebral current path and density, thus avoiding deeper cortical areas associated with memory (eg, hippocampus) and minimizing cognitive adverse effects. As with ECT, however, anesthesia and muscle relaxation are required. Presently, MST remains investigational.

Other potential indications

In addition to MDD, TMS is also being studied as a potential treatment for other neuropsychiatric disorders.

Continue to: Obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD). A recent double-blind study that evaluated a deep TMS (DTMS) device reported a significantly better outcome based on the Yale-Brown Obsessive-Compulsive Scale score with active high-frequency (20 Hz) DTMS (n = 18) vs a sham control (n = 15).¹⁷ The initial benefit persisted up to 1 month after the end of treatment. The authors speculated that this benefit may be due to direct modulation of the anterior cingulate cortex. These results led to the first FDA clearance of a deep TMS device for treating OCD.

Cognition. Because TMS does not require a seizure to produce its antidepressant effect and does not require anesthesia, the risk of neurocognitive disruption is low. In fact, evidence suggests TMS may have beneficial cognitive effects.¹⁸

In an effort to take advantage of this benefit, researchers have explored providing psychoeducation and psychotherapy sessions (eg, behavioral activation) during TMS treatments (“online”).^19,20 The rationale is that neurocircuitry subserving various cognitive functions may be in a heightened state of receptivity during a TMS treatment, which would allow patients to assimilate and better utilize the therapeutic information provided.^19,20

Researchers are also looking at the use of TMS to treat patients with mild cognitive impairment or early dementia. These patients often experience comorbid depression, and TMS could potentially improve memory via both its pro-cognitive and antidepressant effects.¹ The lack of effective treatments for dementia supports pursuing TMS as a therapeutic option for these patients.

Other neuropsychiatric disorders. In addition to early-onset cognitive problems, other neurologic indications with promising data for TMS include chronic pain syndromes, Parkinson’s disease, tinnitus, and migraine headaches (a hand-held FDA-cleared device is now available for treating migraines). In addition to OCD and bipolar depression, other psychiatric indications with promising data include schizophrenia (eg, refractory auditory hallucinations, negative symptoms), posttraumatic stress disorder, and various addictive disorders.²¹ Because results have been mixed for most of these disorders, definitive trials are needed to clearly characterize the potential role of TMS.

Continue to: An ongoing evolution

Neuromodulation is undergoing a renaissance spurred on by the need for more effective treatments to manage some of our most challenging illnesses. Transcranial magnetic stimulation and other forms of therapeutic neuromodulation are welcome additions for managing treatment-resistant depression, OCD, and possibly other disorders. But perhaps their greatest value is as a bellwether for what’s to come. In addition to the ongoing refinements to existing neuro­modulation devices, newer modulation approaches (eg, temporal interference stimulation) and the search for reliable biomarkers may dramatically expand and enhance our clinical options.^14,22

Bottom Line

Transcranial magnetic stimulation (TMS) continues to evolve as a nonpharmacologic treatment for mood disorders, obsessive-compulsive disorder, and potentially for other indications. Recent developments, including altered treatment parameters, new devices, and strategies for increasing the durability of antidepressant effects, have enhanced the benefits of TMS.

Related Resources

• Ziemann U. Thirty years of transcranial magnetic stimulation: where do we stand? Exp Brain Res. 2017;235(4):973-984.
• Janicak PG, Sackett V, Kudrna K, et al. Transcranial magnetic stimulation for the treatment of major depression: an update on recent advances. Current Psychiatry. 2016:15(6):49-56.

[embed:render:related:node:206992]

Therapeutic neuromodulation takes advantage of the brain’s electrochemical makeup. This allows for treatment devices that modulate neurocircuits relevant to behaviors disrupted in disorders such as major depressive disorder (MDD) (eg, sleep quality, appetite, cognitive, and executive functions). The default mode network (comprised of structures such as the medial prefrontal cortex [MPFC], the posterior cingulate cortex, the hippocampus, and their functional connectivity) serves as a prime example of circuitry that can be targeted by this approach.¹

For 80 years, electroconvulsive therapy (ECT) has been an important neuromodulation option for patients with more severe illness. Recently, additional neuromodulatory approaches have been FDA-cleared, including transcranial magnetic stimulation (TMS), vagus nerve stimulation (VNS), and deep brain stimulation (DBS). Another approach, transcranial direct current stimulation (tDCS), has been extensively studied for its potential clinical utility but is not FDA-cleared. The Table provides descriptions of these therapies.

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An evolving therapeutic option

While primarily studied as a monotherapy for MDD, in clinical practice TMS (Box) is typically used as an adjunct to medication and psychotherapy.^2,3 In this context, it has demonstrated efficacy for more difficult-to-treat mood disorders with an excellent safety and tolerability profile whether used with or without medication.^4-6

To further improve the efficiency and efficacy of TMS while maintaining its safety and tolerability, researchers and clinicians have been exploring a few initiatives.

Box

Altered treatment parameters

One initiative is assessing the feasibility of altering various treatment parameters, such as the total number of treatment sessions (30 to 60 sessions); the frequency of sessions (eg, more than once daily); the total number of magnetic pulses per session (eg, >3,000); the stimulation coil localization (eg, left vs right dorsal lateral prefrontal cortex [DLPFC]; MPFC; and various methods to determine optimal coil placement (eg, EEG F3 coordinate or MRI-guided neuro-navigational methods). Such refinements offer the potential for enhanced efficacy, shorter treatment sessions, and/or improved tolerability. For example, lower frequency right DLPFC stimulations (eg, 1 Hz) can decrease the risk of seizures and improve overall tolerability. While this has not been studied as extensively as higher frequency left DLPFC stimulations (eg, 5 to 20 Hz), existing evidence supports similar efficacy between these 2 approaches.⁷

Theta burst stimulation. Some TMS devices can be adapted to deliver theta burst stimulation (TBS). This produces trains of triple, 50 Hz, pulsed bursts (usually with 200 ms inter-burst intervals occurring at a rate of 5 Hz; at 80% MT) to model naturally occurring theta rhythms. These bursts can be administered in stimulation protocols using intermittent TBS (iTBS) (eg, 10 bursts of triplets over 2 seconds every 10 seconds; 30 pulses per burst; for approximately 3 minutes; totaling 600 pulses) or continuous TBS (cTBS) bursts given in an uninterrupted train (eg, 40 seconds, 600 pulses). Evidence indicates these protocols facilitate long-term potentiation (ie, iTBS) and long-term depression (ie, cTBS), which in turn can modulate synaptic plasticity.

Continue to: While some clinicians are using...

While some clinicians are using TBS off-label, a recent non-inferiority trial (N = 395) reported similar efficacy and safety comparing standard 10 Hz TMS to an iTBS protocol at 120% of resting motor threshold (both over the left DLPFC).⁸ This has led to FDA clearance of the TMS device adapted to provide iTBS in this trial.⁸

From a more practical perspective, TBS has the potential to reduce the number of pulses (eg, 600 vs 3,000) and the total number of sessions required, as well as the duration of treatment sessions (eg, 37.5 minutes to <5 minutes). This can accelerate the time to response and decrease patient and staff commitment, with resulting cost savings.⁹ Despite this recent progress, ongoing research still needs to clarify issues such as the risk/benefit profile, particularly in younger and older populations, as well as assessment of duration of initial benefit and appropriate maintenance strategies.

New devices

Another initiative is the development of alternative TMS equipment. For example, newer coil designs with enhanced cooling ability allow for a substantial decrease in the required inter-train interval duration between stimulation trains, thus shortening the total session duration by approximately 50% (eg, from 37.5 to 19 minutes). The use of different coil arrays (eg, the H-coil capable of deeper vs surface stimulation) may allow for more direct stimulation of relevant neurocircuitry (eg, cingulate cortex), possibly improving efficacy and shortening time to onset of benefit. However, in head-to-head comparisons with single-coil devices, enhanced efficacy for depression has not been clearly demonstrated. One caveat is that the increase in depth of magnetic field penetration results in a loss of focality, resulting in the stimulation of larger brain areas. This might increase the risk of adverse effects such as seizures.

Increasing durability of effect

Because high relapse and recurrence rates compromise the initial benefit of any antidepressant therapy, appropriate maintenance strategies are essential. Several studies have evaluated strategies to maintain the acute benefit of TMS for treatment-resistant depression.

One was a 6-month, open-label TMS durability of effect trial for acute responders (n = 99) in the pivotal registration study.⁵ During this study, all participants were given antidepressant medication monotherapy. In addition, with early indication of relapse, patients received a reintroduction of TMS sessions (32/99 patients; mean number of sessions = 14.3). With this protocol, approximately 84% re-achieved their response status. The overall relapse rate was approximately 13%.⁵

Continue to: In a 1-year naturalistic study...

In a 1-year naturalistic study, 63% of patients (75/120) who met response or remission criteria after an acute course of TMS still met response criteria after 12 months. These patients received clinician-determined maintenance treatment that included reintroduction of TMS when indicated.³

In a prospective, 12-month, multisite, randomized pilot study, 67 patients with treatment-resistant MDD underwent an antidepressant medication washout and then received 30 sessions of TMS monotherapy.¹⁰ Those who met criteria for improvement (n = 49) were then randomized to once-monthly TMS or observation only. All patients remained medication-free but could receive TMS re-introduction if they deteriorated. At the end of the study, both groups demonstrated comparable outcomes, with a trend to a longer time before relapse among participants who received once-monthly TMS. Although these results are preliminary, they suggest that some patients could be treated both acutely and then maintained with TMS alone.

Re-introducing TMS in patients who show early signs of relapse after having an initial response achieves rates of sustained improvement that compare favorably with those of other strategies used to manage patients with treatment-resistant depression.

TMS vs ECT

The question often arises as to whether TMS is a viable alternate treatment to ECT. I believe the answer is unequivocally yes and no. By this, I mean some patients who in the past only had ECT as their next option when medications and psychotherapy were insufficient may now consider TMS. In support, there is evidence of comparable efficacy between TMS and ECT in a subgroup of patients who were considered clinically appropriate for ECT.^11-13

How to best identify this group remains unclear, but investigators are exploring predictive biomarkers. For example, a large study (N = 1,188), with functional magnetic resonance imaging (fMRI) reported that depressed patients could be divided into 4 neurophysiological “biotypes” based on different patterns of aberrant connectivity in limbic and fronto-striatal networks.¹⁴ The authors further noted that such distinctions were helpful in predicting response in a subgroup of patients (n = 154) who received TMS.

Continue to: For now...

For now, experience indicates certain clinical factors may provide some guidance. Patients are usually better served by ECT if they:

• have depressive episodes of longer duration (eg, >3 years)
• have a high risk of suicide
• have psychotic or catatonic features associated with their depression
• have difficulty maintaining their physical well-being
• have bipolar depression.

Although existing evidence supports a possible benefit with TMS for bipolar depression (used in combination with a mood stabilizer), the lack of a definitive trial (precluding FDA clearance for this indication) and the lack of insurance coverage both limit the routine use of TMS for this indication.¹⁵

One potential advantage of TMS over ECT is a lower cost.¹³ Transcranial magnetic stimulation also may make it possible to achieve similar efficacy as ECT with fewer cognitive adverse effects when used in combination with ECT to reduce the number of acute ECT treatments required or as part of a maintenance strategy after a patient experiences an acute response to ECT.¹³

Magnetic seizure therapy (MST) vs ECT. An experimental treatment, MST uses a TMS device capable of producing more intense magnetic fields sufficient to induce a seizure.¹⁶ The advantage of MST over ECT-induced seizures is better control of intra-cerebral current path and density, thus avoiding deeper cortical areas associated with memory (eg, hippocampus) and minimizing cognitive adverse effects. As with ECT, however, anesthesia and muscle relaxation are required. Presently, MST remains investigational.

Other potential indications

In addition to MDD, TMS is also being studied as a potential treatment for other neuropsychiatric disorders.

Continue to: Obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD). A recent double-blind study that evaluated a deep TMS (DTMS) device reported a significantly better outcome based on the Yale-Brown Obsessive-Compulsive Scale score with active high-frequency (20 Hz) DTMS (n = 18) vs a sham control (n = 15).¹⁷ The initial benefit persisted up to 1 month after the end of treatment. The authors speculated that this benefit may be due to direct modulation of the anterior cingulate cortex. These results led to the first FDA clearance of a deep TMS device for treating OCD.

Cognition. Because TMS does not require a seizure to produce its antidepressant effect and does not require anesthesia, the risk of neurocognitive disruption is low. In fact, evidence suggests TMS may have beneficial cognitive effects.¹⁸

In an effort to take advantage of this benefit, researchers have explored providing psychoeducation and psychotherapy sessions (eg, behavioral activation) during TMS treatments (“online”).^19,20 The rationale is that neurocircuitry subserving various cognitive functions may be in a heightened state of receptivity during a TMS treatment, which would allow patients to assimilate and better utilize the therapeutic information provided.^19,20

Researchers are also looking at the use of TMS to treat patients with mild cognitive impairment or early dementia. These patients often experience comorbid depression, and TMS could potentially improve memory via both its pro-cognitive and antidepressant effects.¹ The lack of effective treatments for dementia supports pursuing TMS as a therapeutic option for these patients.

Other neuropsychiatric disorders. In addition to early-onset cognitive problems, other neurologic indications with promising data for TMS include chronic pain syndromes, Parkinson’s disease, tinnitus, and migraine headaches (a hand-held FDA-cleared device is now available for treating migraines). In addition to OCD and bipolar depression, other psychiatric indications with promising data include schizophrenia (eg, refractory auditory hallucinations, negative symptoms), posttraumatic stress disorder, and various addictive disorders.²¹ Because results have been mixed for most of these disorders, definitive trials are needed to clearly characterize the potential role of TMS.

Continue to: An ongoing evolution

Neuromodulation is undergoing a renaissance spurred on by the need for more effective treatments to manage some of our most challenging illnesses. Transcranial magnetic stimulation and other forms of therapeutic neuromodulation are welcome additions for managing treatment-resistant depression, OCD, and possibly other disorders. But perhaps their greatest value is as a bellwether for what’s to come. In addition to the ongoing refinements to existing neuro­modulation devices, newer modulation approaches (eg, temporal interference stimulation) and the search for reliable biomarkers may dramatically expand and enhance our clinical options.^14,22

Bottom Line

Transcranial magnetic stimulation (TMS) continues to evolve as a nonpharmacologic treatment for mood disorders, obsessive-compulsive disorder, and potentially for other indications. Recent developments, including altered treatment parameters, new devices, and strategies for increasing the durability of antidepressant effects, have enhanced the benefits of TMS.

Related Resources

• Ziemann U. Thirty years of transcranial magnetic stimulation: where do we stand? Exp Brain Res. 2017;235(4):973-984.
• Janicak PG, Sackett V, Kudrna K, et al. Transcranial magnetic stimulation for the treatment of major depression: an update on recent advances. Current Psychiatry. 2016:15(6):49-56.

[embed:render:related:node:206992]

Since 2008, the FDA has cleared 4 transcranial magnetic stimulation (TMS) devices for treating depression (Related Resources). In that time, the availability of TMS has steadily grown within and outside the United States.

Parallel with increasing clinical utilization of this technology, research continues into the benefit of TMS for treatment-resistant depression; such research includes additional, supportive, acute, sham-controlled trials; comparison trials with electroconvulsive therapy (ECT) for more severe episodes of depression; short- and long-term real-world outcome studies; exploration of alternative treatment parameters to further enhance its efficacy; and the development of other TMS approaches. In this article, we review recent developments in the application of TMS to treat major depressive disorder—in particular, treatment-resistant depression (Box).
 

RTEmagicC_CP015060049_b1.jpg.jpg

Therapeutic neuromodulation
The underlying premise of neuromodulation is that the brain is an electrochemical organ that can be modulated by pharmacotherapy or device-based approaches, or their combination.¹ ECT is the prototypic device-based neuromodulation approach, and remains one of the most effective treatments for severe depression.

More recently, however, other methods have been, and continue to be, developed to treat patients who do not achieve adequate benefit from psychotherapy or medical therapy, or both, and who might not be an ideal candidate for ECT (Table,¹). In addition to the potential therapeutic benefit of these alternative strategies, some could avoid safety and tolerability concerns associated with medication (weight gain, sexual dysfunction) and ECT (eg, cognitive deficits).

RTEmagicC_CP015060049_t1.jpg.jpg

TMS, which utilizes intense, localized magnetic fields to alter activity in neural circuits implicated in the pathophysiology of depression, represents an important example of this initiative.²

TMS has established efficacy for depression
Sham-controlled trials. Several randomized, sham-controlled acute trials have demonstrated the efficacy of TMS for treatment-resistant depression.

A recent meta-analysis considered 18 studies (N = 1,970) that met the authors’ criteria for inclusion.³ They found that TMS monotherapy was statistically and clinically more effective than a sham procedure based on:

• improvement in depressive symptoms (mean decrease in baseline Hamilton Depression Rating Scale [HDRS] score, −4.53 [95% CI, −6.11 to −2.96])
• response rate; response was 3 times more likely with TMS (relative risk 3.38 [95% CI, 2.24 to 5.10])
• remission rate; remission was 5 times more likely with TMS (relative risk, 5.07 [95% CI, 2.50 to 10.30]).

Another meta-analysis (7 studies, N = 279) considered TMS as an augmentation strategy to standard medication for treatment-resistant depression.⁴ The authors reported that, based on change in HDRS scores, the pooled standardized mean difference between active and sham TMS augmentation was 0.86 (P < .00001). Furthermore, the pooled response rate with TMS augmentation was 46.6%, compared with 22.1% with the sham procedure (P < .0003).

Acute naturalistic TMS studies. The efficacy of TMS is supported by a large, naturalistic study of 307 patients with treatment-resistant depression who were assessed at baseline and during a standard course of TMS.⁵ Considering change score in the Clinician Global Impressions-Severity (CGI-S) scale, significant improvement was seen from baseline to end of treatment (−1.9 ± 1.4; P < .0001), with a clinician-assessed response rate of 58.0% and remission rate of 37.1%. Of note: Self-reported quality-of-life measures (on the Medical Outcomes Study 36-Item Short-Form Health Survey and EuroQol 5-Dimensions) also significantly improved during this relatively brief period.⁶

Maintenance strategies after acute TMS response. Most patients referred for TMS have a depressive illness characterized by a chronic, relapsing course and inadequate response to pharmacotherapy or psychotherapy, or their combination. An effective maintenance strategy after acute response to TMS is paramount. This includes:

• prolonged tapering schedule after an acute TMS course is completed
• maintenance medication or psychotherapy, or both
• scheduled periodic maintenance TMS sessions (usually as an augmentation strategy)
• reintroduction of TMS as needed with early signs of relapse. In this context, several trials have assessed the durability of acute TMS benefit.

A semi-controlled maintenance study followed 99 patients who had at least a 25% decrease in baseline HDRS score after acute TMS treatment.⁷ They were then tapered from their TMS sessions over 3 weeks while an antidepressant was titrated up. If, at any time during the subsequent 6 months, early signs of depression relapse were noted (ie, change of at least 1 point on the CGI-S for 2 consecutive weeks), TMS was reintroduced. At the end of the trial, 10 patients (13%) had relapsed and 38 (38%) had an exacerbation of symptoms sufficient to warrant reintroduction of TMS. Of those, 32 (84%) re-achieved mood stability.

In another study, 50 patients who had achieved remission during an acute course of TMS were followed for 3 months.⁸ After TMS taper and continued pharmacotherapy or naturalistic follow-up, 29 (58%) remained in remission; 2 (4%) maintained partial response; and 1 (2%) relapsed.

In a controlled, pilot, maintenance trial, 67 unmedicated patients with treatment-resistant depression received an acute course of TMS.⁹ Forty-seven of the responders were then randomized to a 1-year follow-up trial with or without a scheduled monthly TMS session. All patients could receive reintroduction TMS if they met criteria for symptom worsening.

Both groups had a similar outcome. The number of patients who did not require TMS reintroduction was 9 of 23 (39%) in the scheduled TMS group vs 9 of 26 (35%) in the no-scheduled TMS group (P < .1). Although no difference was noted between groups, the authors commented that these preliminary results will help inform larger, more definitive trials. They concluded that both acute and maintenance TMS monotherapy might be an option—for some patients.

A long-term, naturalistic outcomes study followed 257 treatment-resistant depressed patients for 1 year after they responded to an acute course of TMS.¹⁰ In addition to most patients receiving ongoing maintenance medication, they also could receive reintroduction of TMS if symptoms became worse.

Compared with pre-TMS baseline, there was a statistically significant reduction in the mean total score on the CGI-S scale (primary outcome, P < .0001) at the end of acute treatment that was sustained at follow-up. Ninety-six patients (36.2%) required reintroduction of TMS and 75 of 120 (62.5%) who initially met response or remission criteria after acute treatment continued to meet response criteria after 1 year. The authors concluded that TMS demonstrated both a statistically and clinically meaningful durability of acute benefit during this time frame.

TMS and electroconvulsive therapy
For more than 75 years, ECT has consistently proved to be an effective treatment for major depressive disorder. Although the use of ECT has fluctuated over this period, one practice survey estimated that 100,000 patients receive ECT annually.¹¹

ECT has limitations, however, including cost, the need for general anesthesia, and cognitive deficits that range from short-term confusion to anterograde and retrograde amnesia, which can persist for weeks beyond active treatment.¹² Despite increasing awareness of mental illness, stigma also remains a significant barrier to receiving ECT.

TMS vs ECT. Several trials have directly compared ECT and TMS:

• A recent meta-analysis of 9 trials included 384 patients with depression who were considered clinically appropriate for ECT and were randomized to one or the other treatment.¹³ Both modalities produced a significant reduction in baseline HDRS score, but ECT (15.4 point reduction) was superior to TMS (9.3 point reduction) in the degree of improvement (P < .01).
• Another meta-analysis of 9 trials (N = 425) found ECT superior to TMS in terms of response (P < .03) and remission (P < .006) rates, based on improvement in the HDRS score.¹⁴ When psychotic depressed patients were excluded, however, TMS produced effects equivalent to ECT.

In contrast to what was seen with ECT, cognitive testing of patients who received TMS revealed no deterioration in any domain. Furthermore, one of the comparison studies observed a modest, but statistically significant, improvement in patient’s working memory-executive function, objective memory, and fine-motor speed over the course of TMS treatment.¹⁵

TMS plus ECT. A 2-week, randomized, single-blind, controlled pilot study (N = 22) examined the combination of TMS and ECT as acute treatment of depression.¹⁶ Patients were assigned to receive either unilateral non-dominant (UND) ECT 3 days a week or a combination of 1 UND ECT treatment followed by 4 days of TMS. At the conclusion of treatment, UND ECT plus TMS group produced comparable efficacy and fewer adverse effects compared with the UND ECT-only group.

TMS maintenance after acute ECT response. Most patients who are referred for ECT have a depressive illness characterized by repeated episodes and incomplete response to pharmacotherapy or psychotherapy, or both. The need for an effective maintenance strategy after the acute response is therefore critical. Medication or ECT, or both, are commonly used to maintain acute benefit but, regrettably, a recent systematic review of the durability of benefit with such strategies found a substantial percentage (approximately 50%) of patients relapsed within the first year.¹⁷

• In this context, a case series report found that 1 or 2 weekly, sequential, bilateral TMS treatments after a successful acute course of ECT maintained response in 5 of 6 patients over 6 to 12 months.¹⁸
• Another case series (N = 6) transitioned stable patients from maintenance ECT to maintenance TMS, primarily because of adverse effects with ECT.¹⁹ With a mean frequency of 1 TMS treatment every 3.5 weeks, all 6 patients remained stable for as long as 6 months. Subsequently, 2 patients relapsed—1 at 8 months and 1 at 9 months.

Advantages of maintenance TMS over maintenance ECT include lower cost, fewer adverse effects (particularly cognitive deficits), and the ability to remain independent during the period of the treatment sessions.

TMS as an assessment tool for ECT response. TMS can be used to study excitability in cortical circuits. In a study, EEG potentials evoked by TMS before and after a course of ECT in 8 severely depressed patients revealed an increase in frontal cortical excitability, compared with baseline.²⁰ Such findings support the ability of ECT to produce synaptic potentiation in humans. Furthermore, to the extent that depression presents with alterations in frontal cortical excitability, serial EEG-TMS measurements might be an effective tool to guide and monitor treatment progress with ECT, as well as other forms of therapeutic modulation.

Summing up: TMS and ECT. Although a definitive comparative study is needed, available evidence suggests that TMS might be an alternative treatment in a subgroup of patients who are referred for ECT. Factors that might warrant considering TMS over ECT include:

• patient preference
• fear of anesthesia
• concern about cognitive deficits
• stigma.

Although TMS might offer a workable alternative to ECT for acute and maintenance treatment of depression in selected patients, further refinement of the delivery of TMS is also needed to (1) enhance its efficacy and (2) identify clinical and biological markers to better define this select population.

Standard TMS treatment parameters
Superficial TMS. Superficial TMS for depression typically involves a single coil placed over the left dorsolateral prefrontal cortex. The standard, FDA-approved protocol includes stimulating at 110% of motor threshold with 75, 4-second trains at 10 Hz (ie, 40 stimulations) interspersed by 26-second intertrain intervals. Without interruption, a standard treatment session takes 37.5 minutes and delivers a total of 3,000 pulses. Most patients require 20 to 30 sessions, on a Monday-through-Friday schedule, to achieve optimal benefit.

This approach stimulates to a depth of approximately 2 or 3 cm. The coil usually is placed over the left dorsolateral prefrontal cortex because earlier studies indicated that decreased activity in this part of the brain correlates with symptoms of depression. When TMS is administered in a rapid repetitive fashion (at >1 Hz; typically, at 10 Hz), blood flow and metabolism in that area of the brain are increased. In addition, imaging studies indicate that trans-synaptic connections with deeper parts of the brain also allow modulation of other relevant neural circuits.

An alternate approach, less well-studied, involves low-frequency stimulation over the right dorsolateral prefrontal cortex. Parameters differ from what is used in left high-frequency dorsolateral prefrontal cortex TMS: frequency <1 Hz; train durations as long as 15 minutes; an intertrain interval of 25 to 180 seconds; 120 to 900 stimulations per train; and 2,400 to 18,000 total stimulations.

One hypothesis is that this low-frequency approach selectively stimulates inhibitory interneurons, decreases local neuronal activity and diminishes blood flow to deeper structures, such as the amygdala. Although right low-frequency TMS, compared with left high-frequency TMS, has potential advantages of better tolerability and decreased risk for seizures, its relative efficacy is unclear.

Deep TMS. Studies also are pursuing different coil configurations that allow for more direct stimulation of relevant structures (eg, prefrontal neuronal pathways associated with the reward system).

One of these coil designs (ie, the H-coil), coupled to a Magstim TMS stimulator, recently received FDA clearance for treatment-resistant depression. In the pivotal, sham-controlled study, patients received 20 treatment sessions over 4 weeks.²¹ The treatment protocol consisted of a helmet-like coil placed over the medial and lateral prefrontal cortex. Stimulation parameters included an 18-Hz frequency; stimulation intensity of 120% motor threshold; stimulation train duration of 2 seconds; and an intertrain interval of 20 seconds. The treatment sessions lasted 20.2 minutes and delivered a total of 1,980 stimulations.

Based on the 21-item HDRS, the active treatment coil group achieved a significantly greater decrease in baseline score (6.39 vs 3.28; P < .008); a greater response rate (37% vs 27.8%; P < .03); and a greater remission rate (30.4% vs 15.8%; P < .016) compared with the sham coil group.

Next, in what is the only randomized, controlled maintenance assessment to date, the same patients were followed for an additional 12 weeks, continuing blinded treatments twice weekly. At the end of the second phase, the active treatment group also demonstrated greater benefit than the sham group (P < .03). One seizure did occur, possibly related to excessive alcohol use; but this raises the question of whether treating at a higher frequency (18 Hz) with greater depth and less focality might increase the risk of seizure.

To assess the potential advantages, as well as the relative safety, of this approach over standard TMS delivery, an adequately designed and powered trial comparing the H-coil and a single-coil device is needed.

Alternate TMS approaches
Efforts to improve the clinical effectiveness of TMS for treating depression include several approaches.

Theta burst stimulation (TBS) is a patterned form of TMS pulse delivery that utilizes high and low frequencies in the same stimulus train (eg, three 50-Hz bursts delivered 5 times a second). Such a pulse sequence can modulate long-term depression and long-term potentiation mechanisms that induce plasticity in areas such as the hippocampus.²²

Intermittent TBS (iTBS) administers stimulations over a relatively brief duration (eg, 2 seconds) or intermittently (eg, every 10 seconds) for a specific period (eg, 190 seconds [600 pulses in total]) over the left dorsolateral prefrontal cortex. This technique induces long-term potentiation and produces effects similar to those of high-frequency TMS.

In contrast, continuous TBS (cTBS) administers a continuous train (eg, 40 seconds [600 total pulses]) over the right dorsolateral prefrontal cortex. This induces long-term depression and produces effects similar to low-frequency TMS.

Recent studies using different delivery paradigms have generated mixed results:

Study 1: Fifty-six patients with depression received active treatment; 17 others, a sham procedure.²³ This study used 3 different conditions:

• a combination of low-frequency and high-frequency TMS stimulation, administered over the right and left dorsolateral prefrontal cortices, respectively
• a combination of iTBS over the left dorsolateral prefrontal cortex and cTBS over the right dorsolateral prefrontal cortex
• a sham procedure, in which no magnetic field was created.

Neither active treatment arm separated from the sham procedure based on change scores in the 21-item HDRS (P = not significant).

Study 2: Sixty treatment-resistant depression patients were assigned to cTBS, iTBS, a combination of the 2 procedures, or a sham procedure.²⁴ After 2 weeks, the active treatment arms produced the greatest benefit, based on change in scores on the 17-item HDRS, which differed significantly among the 4 groups (F value = 6.166; P < .001); the iTBS and combination arms demonstrated the most robust effect.

There were also significantly more responders in the iTBS (40.0%) and combination groups (66.7%) than in the cTBS (25.0%) and sham groups (13.3%) (P < .010). A lower level of treatment refractoriness predicted a better outcome.

Study 3: Twenty-nine depressed patients were randomized to cTBS over the right dorsolateral prefrontal cortex or a sham procedure.²⁵ Overall, there was no difference between groups; however, actively treated patients who were unmedicated (n = 3) or remained on a stable dosage of medication during treatment (n = 8) did experience a significantly greater reduction in the HDRS score.

Study 4: In a pilot trial, 32 depressed patients were randomized to 30 sessions of adjunctive combined iTBS plus cTBS or bilateral sham TBS.²⁶ Based on reduction from the baseline Montgomery-Åsberg Depression Rating Scale score, 9 patients in the active treatment group and 4 in the sham group achieved response (odds ratio, 3.86; P < .048).

If at least comparable efficacy can be clearly demonstrated, advantages of TBS over standard TMS include a significantly reduced administration time, which might allow for more patients to be treated and reduce associated costs of treatment.²⁷

Magnetic low-field synchronized stimulation is produced by rotating spherical rare-earth magnets that are synchronized to an individual’s alpha frequency. A recent 6-week, double-blind, sham-controlled trial (N = 202) reported that, in the intention-to-treat population, there was no difference in outcome between treatment arms. In patients who completed the study according to protocol (120 of 202), however, active treatment was significantly better in decreasing baseline HDRS score (P < .033).²⁸

Magnetic seizure therapy (MST) is an experimental approach to treating patients with more severe depression that is resistant to medical therapy. The primary aim is to use TMS to induce a seizure, thus achieving the same efficacy as provided by ECT but without the adverse cognitive effects of ECT. With MST, the TMS device uses much higher stimulation settings to produce a seizure—the goal being to avoid direct electrical current to the brain’s memory centers.²⁹

A pilot study considered the clinical and cognitive effects of MST in a group of 26 treatment-resistant depression patients (10 randomized; 16 open-label).³⁰ Based on reduction in baseline HDRS scores at the end of the trial, 69% of patients achieved response and 46% met remission criteria; however, one-half of patients relapsed within 6 months.

Importantly, no cognitive adverse effects were observed. Furthermore, the antidepressant and anti-anxiety effects of MST were associated with localized metabolic changes in brain areas implicated in the pathophysiology of depression.

The investigators concluded that MST might constitute an effective, well-tolerated, and safe treatment for patients unable to benefit from available medical therapies for depression. In addition to confirmation of acute benefit in more definitive trials, the issue of durability of effect needs further clarification.

TMS is a key component of neuropsychiatric practice
It has been 3 decades since Barker et al³¹ developed the technology to deliver intense, localized magnetic pulses to specific areas of the nervous system. During this period, the role of TMS as a probe of the central and peripheral nervous systems has expanded to include various therapeutic applications, primarily focusing on treatment-resistant major depressive disorder.

Now, increasing sophistication in the choice of stimulation parameters and other ongoing efforts to optimize the benefits of TMS are yielding improved clinical outcomes. Research is still needed to better define the place of TMS in the management of subtypes of depression that are particularly difficult to treat and that do not benefit adequately from medications or psychotherapy or their combination.

Growing support from controlled trials, systematic reviews, meta-analyses, naturalistic outcome studies, and professional guidelines indicate that TMS has an increasingly important role in clinical practice.

Since 2008, the FDA has cleared 4 transcranial magnetic stimulation (TMS) devices for treating depression (Related Resources). In that time, the availability of TMS has steadily grown within and outside the United States.

Parallel with increasing clinical utilization of this technology, research continues into the benefit of TMS for treatment-resistant depression; such research includes additional, supportive, acute, sham-controlled trials; comparison trials with electroconvulsive therapy (ECT) for more severe episodes of depression; short- and long-term real-world outcome studies; exploration of alternative treatment parameters to further enhance its efficacy; and the development of other TMS approaches. In this article, we review recent developments in the application of TMS to treat major depressive disorder—in particular, treatment-resistant depression (Box).
 

RTEmagicC_CP015060049_b1.jpg.jpg

Therapeutic neuromodulation
The underlying premise of neuromodulation is that the brain is an electrochemical organ that can be modulated by pharmacotherapy or device-based approaches, or their combination.¹ ECT is the prototypic device-based neuromodulation approach, and remains one of the most effective treatments for severe depression.

More recently, however, other methods have been, and continue to be, developed to treat patients who do not achieve adequate benefit from psychotherapy or medical therapy, or both, and who might not be an ideal candidate for ECT (Table,¹). In addition to the potential therapeutic benefit of these alternative strategies, some could avoid safety and tolerability concerns associated with medication (weight gain, sexual dysfunction) and ECT (eg, cognitive deficits).

RTEmagicC_CP015060049_t1.jpg.jpg

TMS, which utilizes intense, localized magnetic fields to alter activity in neural circuits implicated in the pathophysiology of depression, represents an important example of this initiative.²

TMS has established efficacy for depression
Sham-controlled trials. Several randomized, sham-controlled acute trials have demonstrated the efficacy of TMS for treatment-resistant depression.

A recent meta-analysis considered 18 studies (N = 1,970) that met the authors’ criteria for inclusion.³ They found that TMS monotherapy was statistically and clinically more effective than a sham procedure based on:

• improvement in depressive symptoms (mean decrease in baseline Hamilton Depression Rating Scale [HDRS] score, −4.53 [95% CI, −6.11 to −2.96])
• response rate; response was 3 times more likely with TMS (relative risk 3.38 [95% CI, 2.24 to 5.10])
• remission rate; remission was 5 times more likely with TMS (relative risk, 5.07 [95% CI, 2.50 to 10.30]).

Another meta-analysis (7 studies, N = 279) considered TMS as an augmentation strategy to standard medication for treatment-resistant depression.⁴ The authors reported that, based on change in HDRS scores, the pooled standardized mean difference between active and sham TMS augmentation was 0.86 (P < .00001). Furthermore, the pooled response rate with TMS augmentation was 46.6%, compared with 22.1% with the sham procedure (P < .0003).

Acute naturalistic TMS studies. The efficacy of TMS is supported by a large, naturalistic study of 307 patients with treatment-resistant depression who were assessed at baseline and during a standard course of TMS.⁵ Considering change score in the Clinician Global Impressions-Severity (CGI-S) scale, significant improvement was seen from baseline to end of treatment (−1.9 ± 1.4; P < .0001), with a clinician-assessed response rate of 58.0% and remission rate of 37.1%. Of note: Self-reported quality-of-life measures (on the Medical Outcomes Study 36-Item Short-Form Health Survey and EuroQol 5-Dimensions) also significantly improved during this relatively brief period.⁶

Maintenance strategies after acute TMS response. Most patients referred for TMS have a depressive illness characterized by a chronic, relapsing course and inadequate response to pharmacotherapy or psychotherapy, or their combination. An effective maintenance strategy after acute response to TMS is paramount. This includes:

• prolonged tapering schedule after an acute TMS course is completed
• maintenance medication or psychotherapy, or both
• scheduled periodic maintenance TMS sessions (usually as an augmentation strategy)
• reintroduction of TMS as needed with early signs of relapse. In this context, several trials have assessed the durability of acute TMS benefit.

A semi-controlled maintenance study followed 99 patients who had at least a 25% decrease in baseline HDRS score after acute TMS treatment.⁷ They were then tapered from their TMS sessions over 3 weeks while an antidepressant was titrated up. If, at any time during the subsequent 6 months, early signs of depression relapse were noted (ie, change of at least 1 point on the CGI-S for 2 consecutive weeks), TMS was reintroduced. At the end of the trial, 10 patients (13%) had relapsed and 38 (38%) had an exacerbation of symptoms sufficient to warrant reintroduction of TMS. Of those, 32 (84%) re-achieved mood stability.

In another study, 50 patients who had achieved remission during an acute course of TMS were followed for 3 months.⁸ After TMS taper and continued pharmacotherapy or naturalistic follow-up, 29 (58%) remained in remission; 2 (4%) maintained partial response; and 1 (2%) relapsed.

In a controlled, pilot, maintenance trial, 67 unmedicated patients with treatment-resistant depression received an acute course of TMS.⁹ Forty-seven of the responders were then randomized to a 1-year follow-up trial with or without a scheduled monthly TMS session. All patients could receive reintroduction TMS if they met criteria for symptom worsening.

Both groups had a similar outcome. The number of patients who did not require TMS reintroduction was 9 of 23 (39%) in the scheduled TMS group vs 9 of 26 (35%) in the no-scheduled TMS group (P < .1). Although no difference was noted between groups, the authors commented that these preliminary results will help inform larger, more definitive trials. They concluded that both acute and maintenance TMS monotherapy might be an option—for some patients.

A long-term, naturalistic outcomes study followed 257 treatment-resistant depressed patients for 1 year after they responded to an acute course of TMS.¹⁰ In addition to most patients receiving ongoing maintenance medication, they also could receive reintroduction of TMS if symptoms became worse.

Compared with pre-TMS baseline, there was a statistically significant reduction in the mean total score on the CGI-S scale (primary outcome, P < .0001) at the end of acute treatment that was sustained at follow-up. Ninety-six patients (36.2%) required reintroduction of TMS and 75 of 120 (62.5%) who initially met response or remission criteria after acute treatment continued to meet response criteria after 1 year. The authors concluded that TMS demonstrated both a statistically and clinically meaningful durability of acute benefit during this time frame.

TMS and electroconvulsive therapy
For more than 75 years, ECT has consistently proved to be an effective treatment for major depressive disorder. Although the use of ECT has fluctuated over this period, one practice survey estimated that 100,000 patients receive ECT annually.¹¹

ECT has limitations, however, including cost, the need for general anesthesia, and cognitive deficits that range from short-term confusion to anterograde and retrograde amnesia, which can persist for weeks beyond active treatment.¹² Despite increasing awareness of mental illness, stigma also remains a significant barrier to receiving ECT.

TMS vs ECT. Several trials have directly compared ECT and TMS:

• A recent meta-analysis of 9 trials included 384 patients with depression who were considered clinically appropriate for ECT and were randomized to one or the other treatment.¹³ Both modalities produced a significant reduction in baseline HDRS score, but ECT (15.4 point reduction) was superior to TMS (9.3 point reduction) in the degree of improvement (P < .01).
• Another meta-analysis of 9 trials (N = 425) found ECT superior to TMS in terms of response (P < .03) and remission (P < .006) rates, based on improvement in the HDRS score.¹⁴ When psychotic depressed patients were excluded, however, TMS produced effects equivalent to ECT.

In contrast to what was seen with ECT, cognitive testing of patients who received TMS revealed no deterioration in any domain. Furthermore, one of the comparison studies observed a modest, but statistically significant, improvement in patient’s working memory-executive function, objective memory, and fine-motor speed over the course of TMS treatment.¹⁵

TMS plus ECT. A 2-week, randomized, single-blind, controlled pilot study (N = 22) examined the combination of TMS and ECT as acute treatment of depression.¹⁶ Patients were assigned to receive either unilateral non-dominant (UND) ECT 3 days a week or a combination of 1 UND ECT treatment followed by 4 days of TMS. At the conclusion of treatment, UND ECT plus TMS group produced comparable efficacy and fewer adverse effects compared with the UND ECT-only group.

TMS maintenance after acute ECT response. Most patients who are referred for ECT have a depressive illness characterized by repeated episodes and incomplete response to pharmacotherapy or psychotherapy, or both. The need for an effective maintenance strategy after the acute response is therefore critical. Medication or ECT, or both, are commonly used to maintain acute benefit but, regrettably, a recent systematic review of the durability of benefit with such strategies found a substantial percentage (approximately 50%) of patients relapsed within the first year.¹⁷

• In this context, a case series report found that 1 or 2 weekly, sequential, bilateral TMS treatments after a successful acute course of ECT maintained response in 5 of 6 patients over 6 to 12 months.¹⁸
• Another case series (N = 6) transitioned stable patients from maintenance ECT to maintenance TMS, primarily because of adverse effects with ECT.¹⁹ With a mean frequency of 1 TMS treatment every 3.5 weeks, all 6 patients remained stable for as long as 6 months. Subsequently, 2 patients relapsed—1 at 8 months and 1 at 9 months.

Advantages of maintenance TMS over maintenance ECT include lower cost, fewer adverse effects (particularly cognitive deficits), and the ability to remain independent during the period of the treatment sessions.

TMS as an assessment tool for ECT response. TMS can be used to study excitability in cortical circuits. In a study, EEG potentials evoked by TMS before and after a course of ECT in 8 severely depressed patients revealed an increase in frontal cortical excitability, compared with baseline.²⁰ Such findings support the ability of ECT to produce synaptic potentiation in humans. Furthermore, to the extent that depression presents with alterations in frontal cortical excitability, serial EEG-TMS measurements might be an effective tool to guide and monitor treatment progress with ECT, as well as other forms of therapeutic modulation.

Summing up: TMS and ECT. Although a definitive comparative study is needed, available evidence suggests that TMS might be an alternative treatment in a subgroup of patients who are referred for ECT. Factors that might warrant considering TMS over ECT include:

• patient preference
• fear of anesthesia
• concern about cognitive deficits
• stigma.

Although TMS might offer a workable alternative to ECT for acute and maintenance treatment of depression in selected patients, further refinement of the delivery of TMS is also needed to (1) enhance its efficacy and (2) identify clinical and biological markers to better define this select population.

Standard TMS treatment parameters
Superficial TMS. Superficial TMS for depression typically involves a single coil placed over the left dorsolateral prefrontal cortex. The standard, FDA-approved protocol includes stimulating at 110% of motor threshold with 75, 4-second trains at 10 Hz (ie, 40 stimulations) interspersed by 26-second intertrain intervals. Without interruption, a standard treatment session takes 37.5 minutes and delivers a total of 3,000 pulses. Most patients require 20 to 30 sessions, on a Monday-through-Friday schedule, to achieve optimal benefit.

This approach stimulates to a depth of approximately 2 or 3 cm. The coil usually is placed over the left dorsolateral prefrontal cortex because earlier studies indicated that decreased activity in this part of the brain correlates with symptoms of depression. When TMS is administered in a rapid repetitive fashion (at >1 Hz; typically, at 10 Hz), blood flow and metabolism in that area of the brain are increased. In addition, imaging studies indicate that trans-synaptic connections with deeper parts of the brain also allow modulation of other relevant neural circuits.

An alternate approach, less well-studied, involves low-frequency stimulation over the right dorsolateral prefrontal cortex. Parameters differ from what is used in left high-frequency dorsolateral prefrontal cortex TMS: frequency <1 Hz; train durations as long as 15 minutes; an intertrain interval of 25 to 180 seconds; 120 to 900 stimulations per train; and 2,400 to 18,000 total stimulations.

One hypothesis is that this low-frequency approach selectively stimulates inhibitory interneurons, decreases local neuronal activity and diminishes blood flow to deeper structures, such as the amygdala. Although right low-frequency TMS, compared with left high-frequency TMS, has potential advantages of better tolerability and decreased risk for seizures, its relative efficacy is unclear.

Deep TMS. Studies also are pursuing different coil configurations that allow for more direct stimulation of relevant structures (eg, prefrontal neuronal pathways associated with the reward system).

One of these coil designs (ie, the H-coil), coupled to a Magstim TMS stimulator, recently received FDA clearance for treatment-resistant depression. In the pivotal, sham-controlled study, patients received 20 treatment sessions over 4 weeks.²¹ The treatment protocol consisted of a helmet-like coil placed over the medial and lateral prefrontal cortex. Stimulation parameters included an 18-Hz frequency; stimulation intensity of 120% motor threshold; stimulation train duration of 2 seconds; and an intertrain interval of 20 seconds. The treatment sessions lasted 20.2 minutes and delivered a total of 1,980 stimulations.

Based on the 21-item HDRS, the active treatment coil group achieved a significantly greater decrease in baseline score (6.39 vs 3.28; P < .008); a greater response rate (37% vs 27.8%; P < .03); and a greater remission rate (30.4% vs 15.8%; P < .016) compared with the sham coil group.

Next, in what is the only randomized, controlled maintenance assessment to date, the same patients were followed for an additional 12 weeks, continuing blinded treatments twice weekly. At the end of the second phase, the active treatment group also demonstrated greater benefit than the sham group (P < .03). One seizure did occur, possibly related to excessive alcohol use; but this raises the question of whether treating at a higher frequency (18 Hz) with greater depth and less focality might increase the risk of seizure.

To assess the potential advantages, as well as the relative safety, of this approach over standard TMS delivery, an adequately designed and powered trial comparing the H-coil and a single-coil device is needed.

Alternate TMS approaches
Efforts to improve the clinical effectiveness of TMS for treating depression include several approaches.

Theta burst stimulation (TBS) is a patterned form of TMS pulse delivery that utilizes high and low frequencies in the same stimulus train (eg, three 50-Hz bursts delivered 5 times a second). Such a pulse sequence can modulate long-term depression and long-term potentiation mechanisms that induce plasticity in areas such as the hippocampus.²²

Intermittent TBS (iTBS) administers stimulations over a relatively brief duration (eg, 2 seconds) or intermittently (eg, every 10 seconds) for a specific period (eg, 190 seconds [600 pulses in total]) over the left dorsolateral prefrontal cortex. This technique induces long-term potentiation and produces effects similar to those of high-frequency TMS.

In contrast, continuous TBS (cTBS) administers a continuous train (eg, 40 seconds [600 total pulses]) over the right dorsolateral prefrontal cortex. This induces long-term depression and produces effects similar to low-frequency TMS.

Recent studies using different delivery paradigms have generated mixed results:

Study 1: Fifty-six patients with depression received active treatment; 17 others, a sham procedure.²³ This study used 3 different conditions:

• a combination of low-frequency and high-frequency TMS stimulation, administered over the right and left dorsolateral prefrontal cortices, respectively
• a combination of iTBS over the left dorsolateral prefrontal cortex and cTBS over the right dorsolateral prefrontal cortex
• a sham procedure, in which no magnetic field was created.

Neither active treatment arm separated from the sham procedure based on change scores in the 21-item HDRS (P = not significant).

Study 2: Sixty treatment-resistant depression patients were assigned to cTBS, iTBS, a combination of the 2 procedures, or a sham procedure.²⁴ After 2 weeks, the active treatment arms produced the greatest benefit, based on change in scores on the 17-item HDRS, which differed significantly among the 4 groups (F value = 6.166; P < .001); the iTBS and combination arms demonstrated the most robust effect.

There were also significantly more responders in the iTBS (40.0%) and combination groups (66.7%) than in the cTBS (25.0%) and sham groups (13.3%) (P < .010). A lower level of treatment refractoriness predicted a better outcome.

Study 3: Twenty-nine depressed patients were randomized to cTBS over the right dorsolateral prefrontal cortex or a sham procedure.²⁵ Overall, there was no difference between groups; however, actively treated patients who were unmedicated (n = 3) or remained on a stable dosage of medication during treatment (n = 8) did experience a significantly greater reduction in the HDRS score.

Study 4: In a pilot trial, 32 depressed patients were randomized to 30 sessions of adjunctive combined iTBS plus cTBS or bilateral sham TBS.²⁶ Based on reduction from the baseline Montgomery-Åsberg Depression Rating Scale score, 9 patients in the active treatment group and 4 in the sham group achieved response (odds ratio, 3.86; P < .048).

If at least comparable efficacy can be clearly demonstrated, advantages of TBS over standard TMS include a significantly reduced administration time, which might allow for more patients to be treated and reduce associated costs of treatment.²⁷

Magnetic low-field synchronized stimulation is produced by rotating spherical rare-earth magnets that are synchronized to an individual’s alpha frequency. A recent 6-week, double-blind, sham-controlled trial (N = 202) reported that, in the intention-to-treat population, there was no difference in outcome between treatment arms. In patients who completed the study according to protocol (120 of 202), however, active treatment was significantly better in decreasing baseline HDRS score (P < .033).²⁸

Magnetic seizure therapy (MST) is an experimental approach to treating patients with more severe depression that is resistant to medical therapy. The primary aim is to use TMS to induce a seizure, thus achieving the same efficacy as provided by ECT but without the adverse cognitive effects of ECT. With MST, the TMS device uses much higher stimulation settings to produce a seizure—the goal being to avoid direct electrical current to the brain’s memory centers.²⁹

A pilot study considered the clinical and cognitive effects of MST in a group of 26 treatment-resistant depression patients (10 randomized; 16 open-label).³⁰ Based on reduction in baseline HDRS scores at the end of the trial, 69% of patients achieved response and 46% met remission criteria; however, one-half of patients relapsed within 6 months.

Importantly, no cognitive adverse effects were observed. Furthermore, the antidepressant and anti-anxiety effects of MST were associated with localized metabolic changes in brain areas implicated in the pathophysiology of depression.

The investigators concluded that MST might constitute an effective, well-tolerated, and safe treatment for patients unable to benefit from available medical therapies for depression. In addition to confirmation of acute benefit in more definitive trials, the issue of durability of effect needs further clarification.

TMS is a key component of neuropsychiatric practice
It has been 3 decades since Barker et al³¹ developed the technology to deliver intense, localized magnetic pulses to specific areas of the nervous system. During this period, the role of TMS as a probe of the central and peripheral nervous systems has expanded to include various therapeutic applications, primarily focusing on treatment-resistant major depressive disorder.

Now, increasing sophistication in the choice of stimulation parameters and other ongoing efforts to optimize the benefits of TMS are yielding improved clinical outcomes. Research is still needed to better define the place of TMS in the management of subtypes of depression that are particularly difficult to treat and that do not benefit adequately from medications or psychotherapy or their combination.

Growing support from controlled trials, systematic reviews, meta-analyses, naturalistic outcome studies, and professional guidelines indicate that TMS has an increasingly important role in clinical practice.

Since 2008, the FDA has cleared 4 transcranial magnetic stimulation (TMS) devices for treating depression (Related Resources). In that time, the availability of TMS has steadily grown within and outside the United States.

Parallel with increasing clinical utilization of this technology, research continues into the benefit of TMS for treatment-resistant depression; such research includes additional, supportive, acute, sham-controlled trials; comparison trials with electroconvulsive therapy (ECT) for more severe episodes of depression; short- and long-term real-world outcome studies; exploration of alternative treatment parameters to further enhance its efficacy; and the development of other TMS approaches. In this article, we review recent developments in the application of TMS to treat major depressive disorder—in particular, treatment-resistant depression (Box).
 

RTEmagicC_CP015060049_b1.jpg.jpg

Therapeutic neuromodulation
The underlying premise of neuromodulation is that the brain is an electrochemical organ that can be modulated by pharmacotherapy or device-based approaches, or their combination.¹ ECT is the prototypic device-based neuromodulation approach, and remains one of the most effective treatments for severe depression.

More recently, however, other methods have been, and continue to be, developed to treat patients who do not achieve adequate benefit from psychotherapy or medical therapy, or both, and who might not be an ideal candidate for ECT (Table,¹). In addition to the potential therapeutic benefit of these alternative strategies, some could avoid safety and tolerability concerns associated with medication (weight gain, sexual dysfunction) and ECT (eg, cognitive deficits).

RTEmagicC_CP015060049_t1.jpg.jpg

TMS, which utilizes intense, localized magnetic fields to alter activity in neural circuits implicated in the pathophysiology of depression, represents an important example of this initiative.²

TMS has established efficacy for depression
Sham-controlled trials. Several randomized, sham-controlled acute trials have demonstrated the efficacy of TMS for treatment-resistant depression.

A recent meta-analysis considered 18 studies (N = 1,970) that met the authors’ criteria for inclusion.³ They found that TMS monotherapy was statistically and clinically more effective than a sham procedure based on:

• improvement in depressive symptoms (mean decrease in baseline Hamilton Depression Rating Scale [HDRS] score, −4.53 [95% CI, −6.11 to −2.96])
• response rate; response was 3 times more likely with TMS (relative risk 3.38 [95% CI, 2.24 to 5.10])
• remission rate; remission was 5 times more likely with TMS (relative risk, 5.07 [95% CI, 2.50 to 10.30]).

Another meta-analysis (7 studies, N = 279) considered TMS as an augmentation strategy to standard medication for treatment-resistant depression.⁴ The authors reported that, based on change in HDRS scores, the pooled standardized mean difference between active and sham TMS augmentation was 0.86 (P < .00001). Furthermore, the pooled response rate with TMS augmentation was 46.6%, compared with 22.1% with the sham procedure (P < .0003).

Acute naturalistic TMS studies. The efficacy of TMS is supported by a large, naturalistic study of 307 patients with treatment-resistant depression who were assessed at baseline and during a standard course of TMS.⁵ Considering change score in the Clinician Global Impressions-Severity (CGI-S) scale, significant improvement was seen from baseline to end of treatment (−1.9 ± 1.4; P < .0001), with a clinician-assessed response rate of 58.0% and remission rate of 37.1%. Of note: Self-reported quality-of-life measures (on the Medical Outcomes Study 36-Item Short-Form Health Survey and EuroQol 5-Dimensions) also significantly improved during this relatively brief period.⁶

Maintenance strategies after acute TMS response. Most patients referred for TMS have a depressive illness characterized by a chronic, relapsing course and inadequate response to pharmacotherapy or psychotherapy, or their combination. An effective maintenance strategy after acute response to TMS is paramount. This includes:

• prolonged tapering schedule after an acute TMS course is completed
• maintenance medication or psychotherapy, or both
• scheduled periodic maintenance TMS sessions (usually as an augmentation strategy)
• reintroduction of TMS as needed with early signs of relapse. In this context, several trials have assessed the durability of acute TMS benefit.

A semi-controlled maintenance study followed 99 patients who had at least a 25% decrease in baseline HDRS score after acute TMS treatment.⁷ They were then tapered from their TMS sessions over 3 weeks while an antidepressant was titrated up. If, at any time during the subsequent 6 months, early signs of depression relapse were noted (ie, change of at least 1 point on the CGI-S for 2 consecutive weeks), TMS was reintroduced. At the end of the trial, 10 patients (13%) had relapsed and 38 (38%) had an exacerbation of symptoms sufficient to warrant reintroduction of TMS. Of those, 32 (84%) re-achieved mood stability.

In another study, 50 patients who had achieved remission during an acute course of TMS were followed for 3 months.⁸ After TMS taper and continued pharmacotherapy or naturalistic follow-up, 29 (58%) remained in remission; 2 (4%) maintained partial response; and 1 (2%) relapsed.

In a controlled, pilot, maintenance trial, 67 unmedicated patients with treatment-resistant depression received an acute course of TMS.⁹ Forty-seven of the responders were then randomized to a 1-year follow-up trial with or without a scheduled monthly TMS session. All patients could receive reintroduction TMS if they met criteria for symptom worsening.

Both groups had a similar outcome. The number of patients who did not require TMS reintroduction was 9 of 23 (39%) in the scheduled TMS group vs 9 of 26 (35%) in the no-scheduled TMS group (P < .1). Although no difference was noted between groups, the authors commented that these preliminary results will help inform larger, more definitive trials. They concluded that both acute and maintenance TMS monotherapy might be an option—for some patients.

A long-term, naturalistic outcomes study followed 257 treatment-resistant depressed patients for 1 year after they responded to an acute course of TMS.¹⁰ In addition to most patients receiving ongoing maintenance medication, they also could receive reintroduction of TMS if symptoms became worse.

Compared with pre-TMS baseline, there was a statistically significant reduction in the mean total score on the CGI-S scale (primary outcome, P < .0001) at the end of acute treatment that was sustained at follow-up. Ninety-six patients (36.2%) required reintroduction of TMS and 75 of 120 (62.5%) who initially met response or remission criteria after acute treatment continued to meet response criteria after 1 year. The authors concluded that TMS demonstrated both a statistically and clinically meaningful durability of acute benefit during this time frame.

TMS and electroconvulsive therapy
For more than 75 years, ECT has consistently proved to be an effective treatment for major depressive disorder. Although the use of ECT has fluctuated over this period, one practice survey estimated that 100,000 patients receive ECT annually.¹¹

ECT has limitations, however, including cost, the need for general anesthesia, and cognitive deficits that range from short-term confusion to anterograde and retrograde amnesia, which can persist for weeks beyond active treatment.¹² Despite increasing awareness of mental illness, stigma also remains a significant barrier to receiving ECT.

TMS vs ECT. Several trials have directly compared ECT and TMS:

• A recent meta-analysis of 9 trials included 384 patients with depression who were considered clinically appropriate for ECT and were randomized to one or the other treatment.¹³ Both modalities produced a significant reduction in baseline HDRS score, but ECT (15.4 point reduction) was superior to TMS (9.3 point reduction) in the degree of improvement (P < .01).
• Another meta-analysis of 9 trials (N = 425) found ECT superior to TMS in terms of response (P < .03) and remission (P < .006) rates, based on improvement in the HDRS score.¹⁴ When psychotic depressed patients were excluded, however, TMS produced effects equivalent to ECT.

In contrast to what was seen with ECT, cognitive testing of patients who received TMS revealed no deterioration in any domain. Furthermore, one of the comparison studies observed a modest, but statistically significant, improvement in patient’s working memory-executive function, objective memory, and fine-motor speed over the course of TMS treatment.¹⁵

TMS plus ECT. A 2-week, randomized, single-blind, controlled pilot study (N = 22) examined the combination of TMS and ECT as acute treatment of depression.¹⁶ Patients were assigned to receive either unilateral non-dominant (UND) ECT 3 days a week or a combination of 1 UND ECT treatment followed by 4 days of TMS. At the conclusion of treatment, UND ECT plus TMS group produced comparable efficacy and fewer adverse effects compared with the UND ECT-only group.

TMS maintenance after acute ECT response. Most patients who are referred for ECT have a depressive illness characterized by repeated episodes and incomplete response to pharmacotherapy or psychotherapy, or both. The need for an effective maintenance strategy after the acute response is therefore critical. Medication or ECT, or both, are commonly used to maintain acute benefit but, regrettably, a recent systematic review of the durability of benefit with such strategies found a substantial percentage (approximately 50%) of patients relapsed within the first year.¹⁷

• In this context, a case series report found that 1 or 2 weekly, sequential, bilateral TMS treatments after a successful acute course of ECT maintained response in 5 of 6 patients over 6 to 12 months.¹⁸
• Another case series (N = 6) transitioned stable patients from maintenance ECT to maintenance TMS, primarily because of adverse effects with ECT.¹⁹ With a mean frequency of 1 TMS treatment every 3.5 weeks, all 6 patients remained stable for as long as 6 months. Subsequently, 2 patients relapsed—1 at 8 months and 1 at 9 months.

Advantages of maintenance TMS over maintenance ECT include lower cost, fewer adverse effects (particularly cognitive deficits), and the ability to remain independent during the period of the treatment sessions.

TMS as an assessment tool for ECT response. TMS can be used to study excitability in cortical circuits. In a study, EEG potentials evoked by TMS before and after a course of ECT in 8 severely depressed patients revealed an increase in frontal cortical excitability, compared with baseline.²⁰ Such findings support the ability of ECT to produce synaptic potentiation in humans. Furthermore, to the extent that depression presents with alterations in frontal cortical excitability, serial EEG-TMS measurements might be an effective tool to guide and monitor treatment progress with ECT, as well as other forms of therapeutic modulation.

Summing up: TMS and ECT. Although a definitive comparative study is needed, available evidence suggests that TMS might be an alternative treatment in a subgroup of patients who are referred for ECT. Factors that might warrant considering TMS over ECT include:

• patient preference
• fear of anesthesia
• concern about cognitive deficits
• stigma.

Although TMS might offer a workable alternative to ECT for acute and maintenance treatment of depression in selected patients, further refinement of the delivery of TMS is also needed to (1) enhance its efficacy and (2) identify clinical and biological markers to better define this select population.

Standard TMS treatment parameters
Superficial TMS. Superficial TMS for depression typically involves a single coil placed over the left dorsolateral prefrontal cortex. The standard, FDA-approved protocol includes stimulating at 110% of motor threshold with 75, 4-second trains at 10 Hz (ie, 40 stimulations) interspersed by 26-second intertrain intervals. Without interruption, a standard treatment session takes 37.5 minutes and delivers a total of 3,000 pulses. Most patients require 20 to 30 sessions, on a Monday-through-Friday schedule, to achieve optimal benefit.

This approach stimulates to a depth of approximately 2 or 3 cm. The coil usually is placed over the left dorsolateral prefrontal cortex because earlier studies indicated that decreased activity in this part of the brain correlates with symptoms of depression. When TMS is administered in a rapid repetitive fashion (at >1 Hz; typically, at 10 Hz), blood flow and metabolism in that area of the brain are increased. In addition, imaging studies indicate that trans-synaptic connections with deeper parts of the brain also allow modulation of other relevant neural circuits.

An alternate approach, less well-studied, involves low-frequency stimulation over the right dorsolateral prefrontal cortex. Parameters differ from what is used in left high-frequency dorsolateral prefrontal cortex TMS: frequency <1 Hz; train durations as long as 15 minutes; an intertrain interval of 25 to 180 seconds; 120 to 900 stimulations per train; and 2,400 to 18,000 total stimulations.

One hypothesis is that this low-frequency approach selectively stimulates inhibitory interneurons, decreases local neuronal activity and diminishes blood flow to deeper structures, such as the amygdala. Although right low-frequency TMS, compared with left high-frequency TMS, has potential advantages of better tolerability and decreased risk for seizures, its relative efficacy is unclear.

Deep TMS. Studies also are pursuing different coil configurations that allow for more direct stimulation of relevant structures (eg, prefrontal neuronal pathways associated with the reward system).

One of these coil designs (ie, the H-coil), coupled to a Magstim TMS stimulator, recently received FDA clearance for treatment-resistant depression. In the pivotal, sham-controlled study, patients received 20 treatment sessions over 4 weeks.²¹ The treatment protocol consisted of a helmet-like coil placed over the medial and lateral prefrontal cortex. Stimulation parameters included an 18-Hz frequency; stimulation intensity of 120% motor threshold; stimulation train duration of 2 seconds; and an intertrain interval of 20 seconds. The treatment sessions lasted 20.2 minutes and delivered a total of 1,980 stimulations.

Based on the 21-item HDRS, the active treatment coil group achieved a significantly greater decrease in baseline score (6.39 vs 3.28; P < .008); a greater response rate (37% vs 27.8%; P < .03); and a greater remission rate (30.4% vs 15.8%; P < .016) compared with the sham coil group.

Next, in what is the only randomized, controlled maintenance assessment to date, the same patients were followed for an additional 12 weeks, continuing blinded treatments twice weekly. At the end of the second phase, the active treatment group also demonstrated greater benefit than the sham group (P < .03). One seizure did occur, possibly related to excessive alcohol use; but this raises the question of whether treating at a higher frequency (18 Hz) with greater depth and less focality might increase the risk of seizure.

To assess the potential advantages, as well as the relative safety, of this approach over standard TMS delivery, an adequately designed and powered trial comparing the H-coil and a single-coil device is needed.

Alternate TMS approaches
Efforts to improve the clinical effectiveness of TMS for treating depression include several approaches.

Theta burst stimulation (TBS) is a patterned form of TMS pulse delivery that utilizes high and low frequencies in the same stimulus train (eg, three 50-Hz bursts delivered 5 times a second). Such a pulse sequence can modulate long-term depression and long-term potentiation mechanisms that induce plasticity in areas such as the hippocampus.²²

Intermittent TBS (iTBS) administers stimulations over a relatively brief duration (eg, 2 seconds) or intermittently (eg, every 10 seconds) for a specific period (eg, 190 seconds [600 pulses in total]) over the left dorsolateral prefrontal cortex. This technique induces long-term potentiation and produces effects similar to those of high-frequency TMS.

In contrast, continuous TBS (cTBS) administers a continuous train (eg, 40 seconds [600 total pulses]) over the right dorsolateral prefrontal cortex. This induces long-term depression and produces effects similar to low-frequency TMS.

Recent studies using different delivery paradigms have generated mixed results:

Study 1: Fifty-six patients with depression received active treatment; 17 others, a sham procedure.²³ This study used 3 different conditions:

• a combination of low-frequency and high-frequency TMS stimulation, administered over the right and left dorsolateral prefrontal cortices, respectively
• a combination of iTBS over the left dorsolateral prefrontal cortex and cTBS over the right dorsolateral prefrontal cortex
• a sham procedure, in which no magnetic field was created.

Neither active treatment arm separated from the sham procedure based on change scores in the 21-item HDRS (P = not significant).

Study 2: Sixty treatment-resistant depression patients were assigned to cTBS, iTBS, a combination of the 2 procedures, or a sham procedure.²⁴ After 2 weeks, the active treatment arms produced the greatest benefit, based on change in scores on the 17-item HDRS, which differed significantly among the 4 groups (F value = 6.166; P < .001); the iTBS and combination arms demonstrated the most robust effect.

There were also significantly more responders in the iTBS (40.0%) and combination groups (66.7%) than in the cTBS (25.0%) and sham groups (13.3%) (P < .010). A lower level of treatment refractoriness predicted a better outcome.

Study 3: Twenty-nine depressed patients were randomized to cTBS over the right dorsolateral prefrontal cortex or a sham procedure.²⁵ Overall, there was no difference between groups; however, actively treated patients who were unmedicated (n = 3) or remained on a stable dosage of medication during treatment (n = 8) did experience a significantly greater reduction in the HDRS score.

Study 4: In a pilot trial, 32 depressed patients were randomized to 30 sessions of adjunctive combined iTBS plus cTBS or bilateral sham TBS.²⁶ Based on reduction from the baseline Montgomery-Åsberg Depression Rating Scale score, 9 patients in the active treatment group and 4 in the sham group achieved response (odds ratio, 3.86; P < .048).

If at least comparable efficacy can be clearly demonstrated, advantages of TBS over standard TMS include a significantly reduced administration time, which might allow for more patients to be treated and reduce associated costs of treatment.²⁷

Magnetic low-field synchronized stimulation is produced by rotating spherical rare-earth magnets that are synchronized to an individual’s alpha frequency. A recent 6-week, double-blind, sham-controlled trial (N = 202) reported that, in the intention-to-treat population, there was no difference in outcome between treatment arms. In patients who completed the study according to protocol (120 of 202), however, active treatment was significantly better in decreasing baseline HDRS score (P < .033).²⁸

Magnetic seizure therapy (MST) is an experimental approach to treating patients with more severe depression that is resistant to medical therapy. The primary aim is to use TMS to induce a seizure, thus achieving the same efficacy as provided by ECT but without the adverse cognitive effects of ECT. With MST, the TMS device uses much higher stimulation settings to produce a seizure—the goal being to avoid direct electrical current to the brain’s memory centers.²⁹

A pilot study considered the clinical and cognitive effects of MST in a group of 26 treatment-resistant depression patients (10 randomized; 16 open-label).³⁰ Based on reduction in baseline HDRS scores at the end of the trial, 69% of patients achieved response and 46% met remission criteria; however, one-half of patients relapsed within 6 months.

Importantly, no cognitive adverse effects were observed. Furthermore, the antidepressant and anti-anxiety effects of MST were associated with localized metabolic changes in brain areas implicated in the pathophysiology of depression.

The investigators concluded that MST might constitute an effective, well-tolerated, and safe treatment for patients unable to benefit from available medical therapies for depression. In addition to confirmation of acute benefit in more definitive trials, the issue of durability of effect needs further clarification.

TMS is a key component of neuropsychiatric practice
It has been 3 decades since Barker et al³¹ developed the technology to deliver intense, localized magnetic pulses to specific areas of the nervous system. During this period, the role of TMS as a probe of the central and peripheral nervous systems has expanded to include various therapeutic applications, primarily focusing on treatment-resistant major depressive disorder.

Now, increasing sophistication in the choice of stimulation parameters and other ongoing efforts to optimize the benefits of TMS are yielding improved clinical outcomes. Research is still needed to better define the place of TMS in the management of subtypes of depression that are particularly difficult to treat and that do not benefit adequately from medications or psychotherapy or their combination.

Growing support from controlled trials, systematic reviews, meta-analyses, naturalistic outcome studies, and professional guidelines indicate that TMS has an increasingly important role in clinical practice.