TBD Meeting (5435-21)

Most patients will not make a full recovery from attention-deficit/hyperactivity disorder in adulthood. This late-breaking finding headlined the World Congress on ADHD – Virtual Event. Held under the specter of SARS-CoV-2, the virtual program delved into the latest research on ADHD pathophysiology, imaging, genetics, and issues on medical and psychiatric comorbidities.

However, one of the conference’s highlights was a piece of unpublished work on remission patterns by Margaret Sibley, PhD, associate professor of psychiatry and behavioral sciences at the University of Washington, Seattle.

Anywhere from 65% to 67% of young adults have desistant ADHD – meaning that they no longer meet criteria. Only up to 23% experience full remission, said Dr. Sibley during a special late-breaking session. All research on remission and most on persistence consider just one endpoint – nothing is known about longitudinal fluctuations in remission status over time.

Her research sought to answer a key question: Do people fully recover from ADHD?

Using data from the Multimodal Treatment of Attention Deficit Hyperactivity Disorder (MTA) Study, Dr. Sibley prospectively followed over 550 children aged 7-9.9 years with DSM-IV combined-type ADHD over 14 years, until 16 years after baseline, using interviews, questionnaires, and rating scales to track symptoms, impairment, and treatment history.

The researchers also came up with a “winning” definition for full remission, which included three or fewer symptoms of inattention and hyperactive impulsivity from all available reporters, negligible ADHD-related impairment based on preestablished impairment rating thresholds, and discontinuation of medication and behavioral treatments for at least a month prior to assessment.

In the longitudinal results, Dr. Sibley and colleagues reported that the majority (63.8%) demonstrated fluctuations between full or partial remission and ADHD recurrence. Only 9.1% sustained full remission over the course of the study. From these findings, ADHD appears to be a fluctuating disorder. While it continues into adulthood for most people, there may also be periods of remission or “good functioning.”

Most desistance from ADHD represents partial, not full remission, said Dr. Sibley. The results also show that recovery by young adulthood is very rare – most patients with remitted ADHD have recurrences.

These are important findings, said Luis Augusto Rohde, MD, PhD, who co-organized the congress’ scientific program committee with Manfred Gerlach, PhD. It shows that a patient’s ADHD may sometimes be more definitive and at other times, no clear phenotype expression emerges.

COVID’s influence

COVID-19 greatly influenced this year’s program’s agenda, said Dr. Rohde. “There’s a lot of evidence that ADHD patients are at greater risk for COVID-19, which is not a surprise,” said Dr. Rohde, professor of child and adolescent psychiatry at the Federal University of Rio Grande do Sul’s department of psychiatry in Porto Alegre, Brazil.

ADHD is a combination of genetic liability and the demands of the environment. “In times like we are living in right now, if you have increasing demands and stress from the environment, you trigger symptoms in those even with lower genetic liability,” he said. ADHD’s pathophysiology involves attention and executive deficit disorder, which means these patients may not follow strategies to avoid infection.

This shows why COVID was so important to the discussion of program topics, he said.

Two experts addressed this subject head on in a point-counterpoint debate, “Residual effects of the 2019 pandemic will mirror the 1918 pandemic: Will we have lots of new ADHD cases?” James Swanson, PhD, professor of pediatrics at the University of California, Irvine, projected that biological coeffects of COVID-19 will lead to ADHD symptoms, generating potentially 5 million new ADHD cases.

David Coghill, MBChB, MD, a professor of child adolescent mental health at the University of Melbourne, countered that not enough data are available yet to back this hypothesis. “Researchers are asking this question, but clinically we don’t know enough.”

While the COVID virus might not directly lead to more cases of ADHD, this could potentially happen indirectly through environmental agents of the pandemic, offered Dr. Rohde. “We’ve clearly seen in our appointments with families and children that they can’t face the amount of schooling and working from home,” he said.

 

Novel treatments

The conference also addressed new treatments and nonpharmacologic interventions in the pipeline for ADHD. “We had a chance to discuss the possibilities about new medications that address the problems in the current market and to show the potential usefulness of nonpharma interventions such as neuromodulations in ADHD,” said Dr. Rohde. Speakers discussed strategies ranging from family-based mindfulness interventions to oligoantigenic diets in children with ADHD.

Other researchers are looking at novel digital tools to help patients manage and treat ADHD. Adherence is a major problem in chronic disorders like hypertension, diabetes, epilepsy, and ADHD, said Dr. Rohde. “Due to ADHD symptomatology including inattention, novelty-seeking, executive deficits, and difficulties in persistence, it is an even bigger problem in this disorder.”

Speakers at the “ADHD in the digital age – From pitfalls to challenges” session discussed video game strategies to reduce ADHD impairment, and a texting app to improve adherence. Dr. Rohde talked about the FOCUS app, which fosters collaboration between patients, families, and caregivers to efficiently track ADHD symptoms and help customize treatments.

Studies suggest these tools can significantly improve adherence. They’re also well accepted by patients, said Dr. Rohde. While the expectations are high, digital interventions are not a substitute for medication. “More data is needed to include them as part of the clinical interventions for ADHD.”

Dr. Sibley received book royalties from Guilford Press. Dr. Rohde has received grant or research support from, served as a consultant to, and served on the speakers’ bureau of Bial, Medice, Novartis/Sandoz, Pfizer, and Shire/Takeda in the last 3 years. The ADHD and Juvenile Bipolar Disorder Outpatient Programs chaired by Dr. Rohde have received unrestricted educational and research support from the following pharmaceutical companies in the last 3 years: Novartis/Sandoz and Shire/Takeda. Dr. Rohde has received authorship royalties from Oxford Press and ArtMed and travel grants from Shire to take part in the 2018 APA annual meeting. Dr. Swanson has two patents: (PIXA4), which uses a “time-of-flight” camera to measure growth of infants, and a provisional patent on the mechanism of tolerance to stimulant medication (PATSMTA). He has received travel support from Medice and has done legal review for NLS. Dr. Coghill worked for several pharmaceutical companies but had no disclosures relevant to the session debate on the pandemic.

Most patients will not make a full recovery from attention-deficit/hyperactivity disorder in adulthood. This late-breaking finding headlined the World Congress on ADHD – Virtual Event. Held under the specter of SARS-CoV-2, the virtual program delved into the latest research on ADHD pathophysiology, imaging, genetics, and issues on medical and psychiatric comorbidities.

However, one of the conference’s highlights was a piece of unpublished work on remission patterns by Margaret Sibley, PhD, associate professor of psychiatry and behavioral sciences at the University of Washington, Seattle.

Anywhere from 65% to 67% of young adults have desistant ADHD – meaning that they no longer meet criteria. Only up to 23% experience full remission, said Dr. Sibley during a special late-breaking session. All research on remission and most on persistence consider just one endpoint – nothing is known about longitudinal fluctuations in remission status over time.

Her research sought to answer a key question: Do people fully recover from ADHD?

Using data from the Multimodal Treatment of Attention Deficit Hyperactivity Disorder (MTA) Study, Dr. Sibley prospectively followed over 550 children aged 7-9.9 years with DSM-IV combined-type ADHD over 14 years, until 16 years after baseline, using interviews, questionnaires, and rating scales to track symptoms, impairment, and treatment history.

The researchers also came up with a “winning” definition for full remission, which included three or fewer symptoms of inattention and hyperactive impulsivity from all available reporters, negligible ADHD-related impairment based on preestablished impairment rating thresholds, and discontinuation of medication and behavioral treatments for at least a month prior to assessment.

In the longitudinal results, Dr. Sibley and colleagues reported that the majority (63.8%) demonstrated fluctuations between full or partial remission and ADHD recurrence. Only 9.1% sustained full remission over the course of the study. From these findings, ADHD appears to be a fluctuating disorder. While it continues into adulthood for most people, there may also be periods of remission or “good functioning.”

Most desistance from ADHD represents partial, not full remission, said Dr. Sibley. The results also show that recovery by young adulthood is very rare – most patients with remitted ADHD have recurrences.

These are important findings, said Luis Augusto Rohde, MD, PhD, who co-organized the congress’ scientific program committee with Manfred Gerlach, PhD. It shows that a patient’s ADHD may sometimes be more definitive and at other times, no clear phenotype expression emerges.

COVID’s influence

COVID-19 greatly influenced this year’s program’s agenda, said Dr. Rohde. “There’s a lot of evidence that ADHD patients are at greater risk for COVID-19, which is not a surprise,” said Dr. Rohde, professor of child and adolescent psychiatry at the Federal University of Rio Grande do Sul’s department of psychiatry in Porto Alegre, Brazil.

ADHD is a combination of genetic liability and the demands of the environment. “In times like we are living in right now, if you have increasing demands and stress from the environment, you trigger symptoms in those even with lower genetic liability,” he said. ADHD’s pathophysiology involves attention and executive deficit disorder, which means these patients may not follow strategies to avoid infection.

This shows why COVID was so important to the discussion of program topics, he said.

Two experts addressed this subject head on in a point-counterpoint debate, “Residual effects of the 2019 pandemic will mirror the 1918 pandemic: Will we have lots of new ADHD cases?” James Swanson, PhD, professor of pediatrics at the University of California, Irvine, projected that biological coeffects of COVID-19 will lead to ADHD symptoms, generating potentially 5 million new ADHD cases.

David Coghill, MBChB, MD, a professor of child adolescent mental health at the University of Melbourne, countered that not enough data are available yet to back this hypothesis. “Researchers are asking this question, but clinically we don’t know enough.”

While the COVID virus might not directly lead to more cases of ADHD, this could potentially happen indirectly through environmental agents of the pandemic, offered Dr. Rohde. “We’ve clearly seen in our appointments with families and children that they can’t face the amount of schooling and working from home,” he said.

 

Novel treatments

The conference also addressed new treatments and nonpharmacologic interventions in the pipeline for ADHD. “We had a chance to discuss the possibilities about new medications that address the problems in the current market and to show the potential usefulness of nonpharma interventions such as neuromodulations in ADHD,” said Dr. Rohde. Speakers discussed strategies ranging from family-based mindfulness interventions to oligoantigenic diets in children with ADHD.

Other researchers are looking at novel digital tools to help patients manage and treat ADHD. Adherence is a major problem in chronic disorders like hypertension, diabetes, epilepsy, and ADHD, said Dr. Rohde. “Due to ADHD symptomatology including inattention, novelty-seeking, executive deficits, and difficulties in persistence, it is an even bigger problem in this disorder.”

Speakers at the “ADHD in the digital age – From pitfalls to challenges” session discussed video game strategies to reduce ADHD impairment, and a texting app to improve adherence. Dr. Rohde talked about the FOCUS app, which fosters collaboration between patients, families, and caregivers to efficiently track ADHD symptoms and help customize treatments.

Studies suggest these tools can significantly improve adherence. They’re also well accepted by patients, said Dr. Rohde. While the expectations are high, digital interventions are not a substitute for medication. “More data is needed to include them as part of the clinical interventions for ADHD.”

Dr. Sibley received book royalties from Guilford Press. Dr. Rohde has received grant or research support from, served as a consultant to, and served on the speakers’ bureau of Bial, Medice, Novartis/Sandoz, Pfizer, and Shire/Takeda in the last 3 years. The ADHD and Juvenile Bipolar Disorder Outpatient Programs chaired by Dr. Rohde have received unrestricted educational and research support from the following pharmaceutical companies in the last 3 years: Novartis/Sandoz and Shire/Takeda. Dr. Rohde has received authorship royalties from Oxford Press and ArtMed and travel grants from Shire to take part in the 2018 APA annual meeting. Dr. Swanson has two patents: (PIXA4), which uses a “time-of-flight” camera to measure growth of infants, and a provisional patent on the mechanism of tolerance to stimulant medication (PATSMTA). He has received travel support from Medice and has done legal review for NLS. Dr. Coghill worked for several pharmaceutical companies but had no disclosures relevant to the session debate on the pandemic.

Most patients will not make a full recovery from attention-deficit/hyperactivity disorder in adulthood. This late-breaking finding headlined the World Congress on ADHD – Virtual Event. Held under the specter of SARS-CoV-2, the virtual program delved into the latest research on ADHD pathophysiology, imaging, genetics, and issues on medical and psychiatric comorbidities.

However, one of the conference’s highlights was a piece of unpublished work on remission patterns by Margaret Sibley, PhD, associate professor of psychiatry and behavioral sciences at the University of Washington, Seattle.

Anywhere from 65% to 67% of young adults have desistant ADHD – meaning that they no longer meet criteria. Only up to 23% experience full remission, said Dr. Sibley during a special late-breaking session. All research on remission and most on persistence consider just one endpoint – nothing is known about longitudinal fluctuations in remission status over time.

Her research sought to answer a key question: Do people fully recover from ADHD?

Using data from the Multimodal Treatment of Attention Deficit Hyperactivity Disorder (MTA) Study, Dr. Sibley prospectively followed over 550 children aged 7-9.9 years with DSM-IV combined-type ADHD over 14 years, until 16 years after baseline, using interviews, questionnaires, and rating scales to track symptoms, impairment, and treatment history.

The researchers also came up with a “winning” definition for full remission, which included three or fewer symptoms of inattention and hyperactive impulsivity from all available reporters, negligible ADHD-related impairment based on preestablished impairment rating thresholds, and discontinuation of medication and behavioral treatments for at least a month prior to assessment.

In the longitudinal results, Dr. Sibley and colleagues reported that the majority (63.8%) demonstrated fluctuations between full or partial remission and ADHD recurrence. Only 9.1% sustained full remission over the course of the study. From these findings, ADHD appears to be a fluctuating disorder. While it continues into adulthood for most people, there may also be periods of remission or “good functioning.”

Most desistance from ADHD represents partial, not full remission, said Dr. Sibley. The results also show that recovery by young adulthood is very rare – most patients with remitted ADHD have recurrences.

These are important findings, said Luis Augusto Rohde, MD, PhD, who co-organized the congress’ scientific program committee with Manfred Gerlach, PhD. It shows that a patient’s ADHD may sometimes be more definitive and at other times, no clear phenotype expression emerges.

COVID’s influence

COVID-19 greatly influenced this year’s program’s agenda, said Dr. Rohde. “There’s a lot of evidence that ADHD patients are at greater risk for COVID-19, which is not a surprise,” said Dr. Rohde, professor of child and adolescent psychiatry at the Federal University of Rio Grande do Sul’s department of psychiatry in Porto Alegre, Brazil.

ADHD is a combination of genetic liability and the demands of the environment. “In times like we are living in right now, if you have increasing demands and stress from the environment, you trigger symptoms in those even with lower genetic liability,” he said. ADHD’s pathophysiology involves attention and executive deficit disorder, which means these patients may not follow strategies to avoid infection.

This shows why COVID was so important to the discussion of program topics, he said.

Two experts addressed this subject head on in a point-counterpoint debate, “Residual effects of the 2019 pandemic will mirror the 1918 pandemic: Will we have lots of new ADHD cases?” James Swanson, PhD, professor of pediatrics at the University of California, Irvine, projected that biological coeffects of COVID-19 will lead to ADHD symptoms, generating potentially 5 million new ADHD cases.

David Coghill, MBChB, MD, a professor of child adolescent mental health at the University of Melbourne, countered that not enough data are available yet to back this hypothesis. “Researchers are asking this question, but clinically we don’t know enough.”

While the COVID virus might not directly lead to more cases of ADHD, this could potentially happen indirectly through environmental agents of the pandemic, offered Dr. Rohde. “We’ve clearly seen in our appointments with families and children that they can’t face the amount of schooling and working from home,” he said.

 

Novel treatments

The conference also addressed new treatments and nonpharmacologic interventions in the pipeline for ADHD. “We had a chance to discuss the possibilities about new medications that address the problems in the current market and to show the potential usefulness of nonpharma interventions such as neuromodulations in ADHD,” said Dr. Rohde. Speakers discussed strategies ranging from family-based mindfulness interventions to oligoantigenic diets in children with ADHD.

Other researchers are looking at novel digital tools to help patients manage and treat ADHD. Adherence is a major problem in chronic disorders like hypertension, diabetes, epilepsy, and ADHD, said Dr. Rohde. “Due to ADHD symptomatology including inattention, novelty-seeking, executive deficits, and difficulties in persistence, it is an even bigger problem in this disorder.”

Speakers at the “ADHD in the digital age – From pitfalls to challenges” session discussed video game strategies to reduce ADHD impairment, and a texting app to improve adherence. Dr. Rohde talked about the FOCUS app, which fosters collaboration between patients, families, and caregivers to efficiently track ADHD symptoms and help customize treatments.

Studies suggest these tools can significantly improve adherence. They’re also well accepted by patients, said Dr. Rohde. While the expectations are high, digital interventions are not a substitute for medication. “More data is needed to include them as part of the clinical interventions for ADHD.”

Dr. Sibley received book royalties from Guilford Press. Dr. Rohde has received grant or research support from, served as a consultant to, and served on the speakers’ bureau of Bial, Medice, Novartis/Sandoz, Pfizer, and Shire/Takeda in the last 3 years. The ADHD and Juvenile Bipolar Disorder Outpatient Programs chaired by Dr. Rohde have received unrestricted educational and research support from the following pharmaceutical companies in the last 3 years: Novartis/Sandoz and Shire/Takeda. Dr. Rohde has received authorship royalties from Oxford Press and ArtMed and travel grants from Shire to take part in the 2018 APA annual meeting. Dr. Swanson has two patents: (PIXA4), which uses a “time-of-flight” camera to measure growth of infants, and a provisional patent on the mechanism of tolerance to stimulant medication (PATSMTA). He has received travel support from Medice and has done legal review for NLS. Dr. Coghill worked for several pharmaceutical companies but had no disclosures relevant to the session debate on the pandemic.

Attention-deficit/hyperactivity disorder and autism spectrum disorder (ASD) often coexist in children and adults, but the range of cognitive abilities can vary widely in these patients. Researchers from around the world are leveraging symptom, cognitive assessment, and neurobiological measures to gain insights on how individuals with ADHD/ASD approach and solve problems.

Several experts discussed the progress of their research during the session, “Overlap and differences of ADHD and autism – new findings of functional imaging and cognition studies” at the World Congress on ADHD – Virtual Event.

“The overlap of these two disorders is a critical issue for our field,” said Sarah Karalunas, PhD, assistant professor of clinical psychology at Purdue University, West Lafayette, Ind., who moderated the session. Clinicians are often asked to make differential diagnoses between these two disorders. Only recently has the DSM-5 allowed their codiagnosis. “There’s increasing recognition that there may be shared cognitive and physiological features that reflect their shared risk and account for the high levels of symptom overlap,” said Dr. Karalunas.
 

Shared cognitive markers

Under the DSM’s change, “it’s now recognized that an estimated 20%-60% of children with ASD have comorbidities with ADHD, and around 20%-40% of children with ADHD have ASD symptoms,” said Beth Johnson, PhD, a research fellow with the Turner Institute for Brain and Mental Health at Monash University, Melbourne.

The shared overlap on genetic traits and comorbidities such as intellectual disability, anxiety, depression, and oppositional defiant disorder, make it difficult for clinicians to predict clinical outcomes, noted Dr. Johnson.

“We’re now understanding that they’re likely to be multiple autisms and ADHDs, that these symptoms exist on a spectrum of severity or ability,” she said. Dr. Johnson discussed a data-driven subtyping approach based on neurocognitive and symptom profiles in children with ADHD. The aim was to better understand how symptoms are managed across ADHD, ASD and comorbid ASD-ADHD.

As part of this research, her team recruited 295 controls and 117 children with ADHD who underwent clinical phenotyping and also completed working memory tasks, stop signal, and sustained attention tasks.

The researchers divided the children into four stable clusters based on the ADHD rating scale and autism questionnaire data: high ASD/ADHD traits, high ADHD/low ASD, low ADHD/moderate ASD, and low ADHD/ASD. Approximately half of the children with ADHD showed moderate to high ASD symptoms. Looking at neurocognition across the tasks, unsurprisingly, performance was lowest among the high-ASD/ADHD children, with performance on the stop signal being the most pronounced. “Notably, performance on the working memory task worsened with increasing ADHD symptoms,” she reported.
 

Drift model identifies information processing

Dr. Karalunas has also compared subgroups of ADHD and ASD children. “Our analysis examined whether cognitive impairments in ASD reflect a shared risk mechanism or co-occurring ADHD symptoms and why we see an overlap in these types of impairments,” she said.

Her study included 509 children with ADHD, 97 with ASD, and 301 controls (typical development). All three groups underwent a full cognitive assessment battery that measured attention arousal, basic processing speed, and working memory. Those tasks were collapsed into a series of variables as well as a set of tasks measuring response inhibition, switching, interference control, reward discounting, and measure of reaction time variability.

Four cognitive profiles emerged: a typically developing group, an ADHD group, an ASD group with low levels of ADHD symptoms and an ASD group with high levels of ADHD symptoms.

The ADHD group did worse on many of the tasks than the control group, and the ASD group with low ADHD levels also did poorly relative to the typically developing sample. This shows that autism – even in absence of co-occurring ADHD – demonstrates more cognitive impairment than typically developing kids. The ADHD group with high levels of autism did the most poorly across all of the tasks.

The findings also revealed a symptom severity pattern: the group with fewer symptoms did the best and the group with the most symptoms did the worst. “Overall, this reflects severity of impairment,” said Dr. Karalunas.

To identify measures more specific to either ADHD or autism, Dr. Karalunas and colleagues did a follow-up analysis to characterize cognitive performance. To accomplish this, they applied a drift-diffusion model to the same four cognitive profiles. The model assessed three parameters: drift rate, which relates to the speed or efficiency of information processing, boundary separation or speed accuracy trade-offs (impulsivity), and nondecision time such as motor preparation.

Using the same four cognitive profiles, they found that the ADHD group had slower drift rate relative to the control, although the two groups did not differ on boundary separation, which meant there were no differences on waiting to need to respond. The ADHD group had faster nondecision times. “This is a classic pattern, shown in the literature,” said Dr. Karalunas.
 

In other results, an interesting pattern began to evolve

Both ASD groups, for example, had much wider boundary separations, which meant they were waiting to be sure before they responded than the ADHD or typically developing groups. In contrast, the two ADHD groups had much faster non-decision times, whereas the two non-ADHD groups had similar nondecisions times.

Unlike the previous analysis, which saw a symptom severity pattern develop, “we’re getting two parameters that seem to track much more specifically to specific symptom domains,” observed Dr. Karalunas.

The results suggest there’s a substantial overlap in cognitive impairments in ADHD/ASD. “But we have pretty strong evidence at this point that these similarities are not accounted for by symptom overlap, especially for things like response and inhibition, working memory and processing speed. These seem to be independently related to ADHD and autism, regardless of the level of comorbid ADHD symptoms in the autism group,” said Dr. Karalunas.

The hope is to expand on these types of analyses to address the interaction of cognition-emotion and social cognition, and empirically define groups based on cognitive performance, she said.
 

Neurocognitive studies

Researchers have also been studying neural networks to assess ASD and ADHD. Roselyne Chauvin, PhD, a postdoctoral associate at Washington University, St. Louis, discussed the concept of “a task generic connectome,” in which researchers look for a common network between targeted task paradigms to get closer to a common alteration across impairments.

In her research, Dr. Chauvin and colleagues looked at connectivity modulations across three tasks: working memory, reward processing tasks, and stop signal tasks, comparing ADHD patients to siblings and controls. The ADHD group showed reduced sensitivity or a smaller number of connections modulated in the tasks compared with the other groups. Researchers wondered where those missed connections were located.

Dividing the cohorts into task generic and task specific groups, Dr. Chauvin and colleagues found that the ADHD group lacked common processing skills. They were also able to identify reproducible missing circuits in the ADHD participants. Among the cohorts, there was a higher modulation of task-specific edges in the ADHD group.

The ADHD patients seemed to be using more task-tailored alternative strategies that were more challenging and suboptimal.

She also previewed her ongoing work with the EU-AIMS Longitudinal European Autism Project (LEAP) database to study ASD-ADHD comorbidity. In this project, she and her colleagues looked at several tasks: probing emotion processing, inhibitory control, theory of mind, and reward anticipation. Comparing ASD groups with or without ADHD comorbidity or a shared connection, she and her team were able to devise a functional profile predictive of ADHD severity. As an example, “for the connection only used by the ASD with ADHD comorbidity, the more they were using those connections of higher amplitude in the modulation, inside this subset of connection, the higher they would have ADHD severity,” said Dr. Chauvin.

Neural correlates of different behavioral and cognitive profiles haven’t been widely studied, according to Charlotte Tye, PhD, who’s based at the Institute of Psychiatry, Psychology & Neuroscience, King’s College, London. Electroencephalography is a useful technique for understanding the neural correlates of cognitive impairments and teasing apart different models of co-occurrence in ASD and ADHD. 

Dr. Tye and colleagues tested this approach in a cohort of boys aged 8-13 years diagnosed with ASD and/or ADHD, measuring EEG while the children did various continuous performance tasks to assess changes in brain activity. Examining P3 amplitude (event-related potential components) they found that children with ADHD or ADHD+ASD showed an attenuated amplitude of the P3, compared with typically developing children and those with ASD.

“This suggests children with an ADHD diagnosis exhibited reduced inhibitory control,” said Dr. Tye. In contrast, children with ASD showed reduced conflict monitoring as indexed by altered N2 amplitude across task conditions.

These, and other studies conducted by Dr. Tye and colleagues indicate that children with ADHD show reduced neural responses during attentional processing, whereas autistic children show typical neural responses, supporting specific profiles.

“Autistic children with a diagnosis of ADHD appear to show the unique patterns of neural responses of autism and ADHD, supporting an additive co-occurrence rather than a distinct condition. This contributes to identification of transdiagnostic subgroups within neurodevelopmental conditions for targeting of personalized intervention, and suggests that children with co-occurring autism and ADHD require support for both conditions,” said Dr. Tye.

An important takeaway from all of these findings is “we can’t look just at how someone does overall on a single test,” said Dr. Karalunas in an interview. “There is a tremendous amount of variability between people who have the same diagnosis, and our research really needs to account for this.”

Attention-deficit/hyperactivity disorder and autism spectrum disorder (ASD) often coexist in children and adults, but the range of cognitive abilities can vary widely in these patients. Researchers from around the world are leveraging symptom, cognitive assessment, and neurobiological measures to gain insights on how individuals with ADHD/ASD approach and solve problems.

Several experts discussed the progress of their research during the session, “Overlap and differences of ADHD and autism – new findings of functional imaging and cognition studies” at the World Congress on ADHD – Virtual Event.

“The overlap of these two disorders is a critical issue for our field,” said Sarah Karalunas, PhD, assistant professor of clinical psychology at Purdue University, West Lafayette, Ind., who moderated the session. Clinicians are often asked to make differential diagnoses between these two disorders. Only recently has the DSM-5 allowed their codiagnosis. “There’s increasing recognition that there may be shared cognitive and physiological features that reflect their shared risk and account for the high levels of symptom overlap,” said Dr. Karalunas.
 

Shared cognitive markers

Under the DSM’s change, “it’s now recognized that an estimated 20%-60% of children with ASD have comorbidities with ADHD, and around 20%-40% of children with ADHD have ASD symptoms,” said Beth Johnson, PhD, a research fellow with the Turner Institute for Brain and Mental Health at Monash University, Melbourne.

The shared overlap on genetic traits and comorbidities such as intellectual disability, anxiety, depression, and oppositional defiant disorder, make it difficult for clinicians to predict clinical outcomes, noted Dr. Johnson.

“We’re now understanding that they’re likely to be multiple autisms and ADHDs, that these symptoms exist on a spectrum of severity or ability,” she said. Dr. Johnson discussed a data-driven subtyping approach based on neurocognitive and symptom profiles in children with ADHD. The aim was to better understand how symptoms are managed across ADHD, ASD and comorbid ASD-ADHD.

As part of this research, her team recruited 295 controls and 117 children with ADHD who underwent clinical phenotyping and also completed working memory tasks, stop signal, and sustained attention tasks.

The researchers divided the children into four stable clusters based on the ADHD rating scale and autism questionnaire data: high ASD/ADHD traits, high ADHD/low ASD, low ADHD/moderate ASD, and low ADHD/ASD. Approximately half of the children with ADHD showed moderate to high ASD symptoms. Looking at neurocognition across the tasks, unsurprisingly, performance was lowest among the high-ASD/ADHD children, with performance on the stop signal being the most pronounced. “Notably, performance on the working memory task worsened with increasing ADHD symptoms,” she reported.
 

Drift model identifies information processing

Dr. Karalunas has also compared subgroups of ADHD and ASD children. “Our analysis examined whether cognitive impairments in ASD reflect a shared risk mechanism or co-occurring ADHD symptoms and why we see an overlap in these types of impairments,” she said.

Her study included 509 children with ADHD, 97 with ASD, and 301 controls (typical development). All three groups underwent a full cognitive assessment battery that measured attention arousal, basic processing speed, and working memory. Those tasks were collapsed into a series of variables as well as a set of tasks measuring response inhibition, switching, interference control, reward discounting, and measure of reaction time variability.

Four cognitive profiles emerged: a typically developing group, an ADHD group, an ASD group with low levels of ADHD symptoms and an ASD group with high levels of ADHD symptoms.

The ADHD group did worse on many of the tasks than the control group, and the ASD group with low ADHD levels also did poorly relative to the typically developing sample. This shows that autism – even in absence of co-occurring ADHD – demonstrates more cognitive impairment than typically developing kids. The ADHD group with high levels of autism did the most poorly across all of the tasks.

The findings also revealed a symptom severity pattern: the group with fewer symptoms did the best and the group with the most symptoms did the worst. “Overall, this reflects severity of impairment,” said Dr. Karalunas.

To identify measures more specific to either ADHD or autism, Dr. Karalunas and colleagues did a follow-up analysis to characterize cognitive performance. To accomplish this, they applied a drift-diffusion model to the same four cognitive profiles. The model assessed three parameters: drift rate, which relates to the speed or efficiency of information processing, boundary separation or speed accuracy trade-offs (impulsivity), and nondecision time such as motor preparation.

Using the same four cognitive profiles, they found that the ADHD group had slower drift rate relative to the control, although the two groups did not differ on boundary separation, which meant there were no differences on waiting to need to respond. The ADHD group had faster nondecision times. “This is a classic pattern, shown in the literature,” said Dr. Karalunas.
 

In other results, an interesting pattern began to evolve

Both ASD groups, for example, had much wider boundary separations, which meant they were waiting to be sure before they responded than the ADHD or typically developing groups. In contrast, the two ADHD groups had much faster non-decision times, whereas the two non-ADHD groups had similar nondecisions times.

Unlike the previous analysis, which saw a symptom severity pattern develop, “we’re getting two parameters that seem to track much more specifically to specific symptom domains,” observed Dr. Karalunas.

The results suggest there’s a substantial overlap in cognitive impairments in ADHD/ASD. “But we have pretty strong evidence at this point that these similarities are not accounted for by symptom overlap, especially for things like response and inhibition, working memory and processing speed. These seem to be independently related to ADHD and autism, regardless of the level of comorbid ADHD symptoms in the autism group,” said Dr. Karalunas.

The hope is to expand on these types of analyses to address the interaction of cognition-emotion and social cognition, and empirically define groups based on cognitive performance, she said.
 

Neurocognitive studies

Researchers have also been studying neural networks to assess ASD and ADHD. Roselyne Chauvin, PhD, a postdoctoral associate at Washington University, St. Louis, discussed the concept of “a task generic connectome,” in which researchers look for a common network between targeted task paradigms to get closer to a common alteration across impairments.

In her research, Dr. Chauvin and colleagues looked at connectivity modulations across three tasks: working memory, reward processing tasks, and stop signal tasks, comparing ADHD patients to siblings and controls. The ADHD group showed reduced sensitivity or a smaller number of connections modulated in the tasks compared with the other groups. Researchers wondered where those missed connections were located.

Dividing the cohorts into task generic and task specific groups, Dr. Chauvin and colleagues found that the ADHD group lacked common processing skills. They were also able to identify reproducible missing circuits in the ADHD participants. Among the cohorts, there was a higher modulation of task-specific edges in the ADHD group.

The ADHD patients seemed to be using more task-tailored alternative strategies that were more challenging and suboptimal.

She also previewed her ongoing work with the EU-AIMS Longitudinal European Autism Project (LEAP) database to study ASD-ADHD comorbidity. In this project, she and her colleagues looked at several tasks: probing emotion processing, inhibitory control, theory of mind, and reward anticipation. Comparing ASD groups with or without ADHD comorbidity or a shared connection, she and her team were able to devise a functional profile predictive of ADHD severity. As an example, “for the connection only used by the ASD with ADHD comorbidity, the more they were using those connections of higher amplitude in the modulation, inside this subset of connection, the higher they would have ADHD severity,” said Dr. Chauvin.

Neural correlates of different behavioral and cognitive profiles haven’t been widely studied, according to Charlotte Tye, PhD, who’s based at the Institute of Psychiatry, Psychology & Neuroscience, King’s College, London. Electroencephalography is a useful technique for understanding the neural correlates of cognitive impairments and teasing apart different models of co-occurrence in ASD and ADHD. 

Dr. Tye and colleagues tested this approach in a cohort of boys aged 8-13 years diagnosed with ASD and/or ADHD, measuring EEG while the children did various continuous performance tasks to assess changes in brain activity. Examining P3 amplitude (event-related potential components) they found that children with ADHD or ADHD+ASD showed an attenuated amplitude of the P3, compared with typically developing children and those with ASD.

“This suggests children with an ADHD diagnosis exhibited reduced inhibitory control,” said Dr. Tye. In contrast, children with ASD showed reduced conflict monitoring as indexed by altered N2 amplitude across task conditions.

These, and other studies conducted by Dr. Tye and colleagues indicate that children with ADHD show reduced neural responses during attentional processing, whereas autistic children show typical neural responses, supporting specific profiles.

“Autistic children with a diagnosis of ADHD appear to show the unique patterns of neural responses of autism and ADHD, supporting an additive co-occurrence rather than a distinct condition. This contributes to identification of transdiagnostic subgroups within neurodevelopmental conditions for targeting of personalized intervention, and suggests that children with co-occurring autism and ADHD require support for both conditions,” said Dr. Tye.

An important takeaway from all of these findings is “we can’t look just at how someone does overall on a single test,” said Dr. Karalunas in an interview. “There is a tremendous amount of variability between people who have the same diagnosis, and our research really needs to account for this.”

Attention-deficit/hyperactivity disorder and autism spectrum disorder (ASD) often coexist in children and adults, but the range of cognitive abilities can vary widely in these patients. Researchers from around the world are leveraging symptom, cognitive assessment, and neurobiological measures to gain insights on how individuals with ADHD/ASD approach and solve problems.

Several experts discussed the progress of their research during the session, “Overlap and differences of ADHD and autism – new findings of functional imaging and cognition studies” at the World Congress on ADHD – Virtual Event.

“The overlap of these two disorders is a critical issue for our field,” said Sarah Karalunas, PhD, assistant professor of clinical psychology at Purdue University, West Lafayette, Ind., who moderated the session. Clinicians are often asked to make differential diagnoses between these two disorders. Only recently has the DSM-5 allowed their codiagnosis. “There’s increasing recognition that there may be shared cognitive and physiological features that reflect their shared risk and account for the high levels of symptom overlap,” said Dr. Karalunas.
 

Shared cognitive markers

Under the DSM’s change, “it’s now recognized that an estimated 20%-60% of children with ASD have comorbidities with ADHD, and around 20%-40% of children with ADHD have ASD symptoms,” said Beth Johnson, PhD, a research fellow with the Turner Institute for Brain and Mental Health at Monash University, Melbourne.

The shared overlap on genetic traits and comorbidities such as intellectual disability, anxiety, depression, and oppositional defiant disorder, make it difficult for clinicians to predict clinical outcomes, noted Dr. Johnson.

“We’re now understanding that they’re likely to be multiple autisms and ADHDs, that these symptoms exist on a spectrum of severity or ability,” she said. Dr. Johnson discussed a data-driven subtyping approach based on neurocognitive and symptom profiles in children with ADHD. The aim was to better understand how symptoms are managed across ADHD, ASD and comorbid ASD-ADHD.

As part of this research, her team recruited 295 controls and 117 children with ADHD who underwent clinical phenotyping and also completed working memory tasks, stop signal, and sustained attention tasks.

The researchers divided the children into four stable clusters based on the ADHD rating scale and autism questionnaire data: high ASD/ADHD traits, high ADHD/low ASD, low ADHD/moderate ASD, and low ADHD/ASD. Approximately half of the children with ADHD showed moderate to high ASD symptoms. Looking at neurocognition across the tasks, unsurprisingly, performance was lowest among the high-ASD/ADHD children, with performance on the stop signal being the most pronounced. “Notably, performance on the working memory task worsened with increasing ADHD symptoms,” she reported.
 

Drift model identifies information processing

Dr. Karalunas has also compared subgroups of ADHD and ASD children. “Our analysis examined whether cognitive impairments in ASD reflect a shared risk mechanism or co-occurring ADHD symptoms and why we see an overlap in these types of impairments,” she said.

Her study included 509 children with ADHD, 97 with ASD, and 301 controls (typical development). All three groups underwent a full cognitive assessment battery that measured attention arousal, basic processing speed, and working memory. Those tasks were collapsed into a series of variables as well as a set of tasks measuring response inhibition, switching, interference control, reward discounting, and measure of reaction time variability.

Four cognitive profiles emerged: a typically developing group, an ADHD group, an ASD group with low levels of ADHD symptoms and an ASD group with high levels of ADHD symptoms.

The ADHD group did worse on many of the tasks than the control group, and the ASD group with low ADHD levels also did poorly relative to the typically developing sample. This shows that autism – even in absence of co-occurring ADHD – demonstrates more cognitive impairment than typically developing kids. The ADHD group with high levels of autism did the most poorly across all of the tasks.

The findings also revealed a symptom severity pattern: the group with fewer symptoms did the best and the group with the most symptoms did the worst. “Overall, this reflects severity of impairment,” said Dr. Karalunas.

To identify measures more specific to either ADHD or autism, Dr. Karalunas and colleagues did a follow-up analysis to characterize cognitive performance. To accomplish this, they applied a drift-diffusion model to the same four cognitive profiles. The model assessed three parameters: drift rate, which relates to the speed or efficiency of information processing, boundary separation or speed accuracy trade-offs (impulsivity), and nondecision time such as motor preparation.

Using the same four cognitive profiles, they found that the ADHD group had slower drift rate relative to the control, although the two groups did not differ on boundary separation, which meant there were no differences on waiting to need to respond. The ADHD group had faster nondecision times. “This is a classic pattern, shown in the literature,” said Dr. Karalunas.
 

In other results, an interesting pattern began to evolve

Both ASD groups, for example, had much wider boundary separations, which meant they were waiting to be sure before they responded than the ADHD or typically developing groups. In contrast, the two ADHD groups had much faster non-decision times, whereas the two non-ADHD groups had similar nondecisions times.

Unlike the previous analysis, which saw a symptom severity pattern develop, “we’re getting two parameters that seem to track much more specifically to specific symptom domains,” observed Dr. Karalunas.

The results suggest there’s a substantial overlap in cognitive impairments in ADHD/ASD. “But we have pretty strong evidence at this point that these similarities are not accounted for by symptom overlap, especially for things like response and inhibition, working memory and processing speed. These seem to be independently related to ADHD and autism, regardless of the level of comorbid ADHD symptoms in the autism group,” said Dr. Karalunas.

The hope is to expand on these types of analyses to address the interaction of cognition-emotion and social cognition, and empirically define groups based on cognitive performance, she said.
 

Neurocognitive studies

Researchers have also been studying neural networks to assess ASD and ADHD. Roselyne Chauvin, PhD, a postdoctoral associate at Washington University, St. Louis, discussed the concept of “a task generic connectome,” in which researchers look for a common network between targeted task paradigms to get closer to a common alteration across impairments.

In her research, Dr. Chauvin and colleagues looked at connectivity modulations across three tasks: working memory, reward processing tasks, and stop signal tasks, comparing ADHD patients to siblings and controls. The ADHD group showed reduced sensitivity or a smaller number of connections modulated in the tasks compared with the other groups. Researchers wondered where those missed connections were located.

Dividing the cohorts into task generic and task specific groups, Dr. Chauvin and colleagues found that the ADHD group lacked common processing skills. They were also able to identify reproducible missing circuits in the ADHD participants. Among the cohorts, there was a higher modulation of task-specific edges in the ADHD group.

The ADHD patients seemed to be using more task-tailored alternative strategies that were more challenging and suboptimal.

She also previewed her ongoing work with the EU-AIMS Longitudinal European Autism Project (LEAP) database to study ASD-ADHD comorbidity. In this project, she and her colleagues looked at several tasks: probing emotion processing, inhibitory control, theory of mind, and reward anticipation. Comparing ASD groups with or without ADHD comorbidity or a shared connection, she and her team were able to devise a functional profile predictive of ADHD severity. As an example, “for the connection only used by the ASD with ADHD comorbidity, the more they were using those connections of higher amplitude in the modulation, inside this subset of connection, the higher they would have ADHD severity,” said Dr. Chauvin.

Neural correlates of different behavioral and cognitive profiles haven’t been widely studied, according to Charlotte Tye, PhD, who’s based at the Institute of Psychiatry, Psychology & Neuroscience, King’s College, London. Electroencephalography is a useful technique for understanding the neural correlates of cognitive impairments and teasing apart different models of co-occurrence in ASD and ADHD. 

Dr. Tye and colleagues tested this approach in a cohort of boys aged 8-13 years diagnosed with ASD and/or ADHD, measuring EEG while the children did various continuous performance tasks to assess changes in brain activity. Examining P3 amplitude (event-related potential components) they found that children with ADHD or ADHD+ASD showed an attenuated amplitude of the P3, compared with typically developing children and those with ASD.

“This suggests children with an ADHD diagnosis exhibited reduced inhibitory control,” said Dr. Tye. In contrast, children with ASD showed reduced conflict monitoring as indexed by altered N2 amplitude across task conditions.

These, and other studies conducted by Dr. Tye and colleagues indicate that children with ADHD show reduced neural responses during attentional processing, whereas autistic children show typical neural responses, supporting specific profiles.

“Autistic children with a diagnosis of ADHD appear to show the unique patterns of neural responses of autism and ADHD, supporting an additive co-occurrence rather than a distinct condition. This contributes to identification of transdiagnostic subgroups within neurodevelopmental conditions for targeting of personalized intervention, and suggests that children with co-occurring autism and ADHD require support for both conditions,” said Dr. Tye.

An important takeaway from all of these findings is “we can’t look just at how someone does overall on a single test,” said Dr. Karalunas in an interview. “There is a tremendous amount of variability between people who have the same diagnosis, and our research really needs to account for this.”

While it’s possible that residual effects of SARS-CoV-2 could lead to an eruption of attention-deficit/hyperactivity disorder (ADHD) cases, a debate at the World Congress on ADHD – Virtual Event underscored the fact that this is still a hypothesis. The bottom line is there needs to be more data, said Luis Augusto Rohde, MD, PhD, cochair of the congress’ scientific program committee and moderator of the session, “Residual effects of the 2019 pandemic will mirror the 1918 pandemic: Will we have lots of new ADHD cases?”

Considering the current pattern of the pandemic, there is not enough evidence for this to be a concern, Dr. Rohde said in an interview.

James Swanson, PhD, professor of pediatrics at the University of California, Irvine, opined that biological co-effects of COVID-19 are likely to have selective effects in children that may produce symptoms representative of ADHD. Using the 1918 Spanish flu pandemic as a historical reference, he estimated that COVID-19 would produce 5 million individuals with new-onset symptoms related to ADHD. “If these cases meet DSM-5 or ICD-11 criteria, there will be lots of new ADHD cases,” he predicted.

David Coghill, MD, a professor of child adolescent mental health at the University of Melbourne, observed that the sums Dr. Swanson presented “are based on maxing out the potential rather than looking at the sums more realistically.”
 

Could the 1918 pandemic offer clues?

In a commentary, Dr. Swanson and Nora D. Volkow, MD, wrote about “lessons learned” from the 1918 pandemic, and how residual sequelae in that era led to a condition labeled hyperkinetic syndrome in children. “It may be worthwhile to consider the hypothesis that the COVID-19 pandemic may result in a novel etiologic subtype of ADHD that clinicians may recognize in patients in the future,” wrote the commentators. 

In survivors of the 1918 pandemic, brain inflammation or encephalitis sometimes emerged as residual sequelae, said Dr. Swanson. In some adult cases, these symptoms were diagnosed as “encephalitis lethargica” (EL) and were associated with Parkinson’s disease. In 1930, based on patients evaluated after 1918, researchers Franz Kramer and Hans Pollnow at Charité Hospital in Berlin described the behavioral manifestation of EL in children as hyperkinetic syndrome, a condition that was characterized by symptoms similar to the properties of ADHD: lack of concentration, insufficient goal orientation, and increased distractibility. “They even reported on autopsy cases that described brain regions that we now know are associated with ADHD from decades of brain imaging studies,” said Dr. Swanson.

COVID-19 rarely results in severe respiratory problems in children but the absolute number requiring hospitalization has accumulated and is now relatively large, said Dr. Swanson. One study of 1,695 severe COVID-19 cases in children and adolescents used MRI and detected neural effects in specific brain regions such as basal ganglia and frontal lobes that previous research had associated with ADHD. Approximately 22% of these rare but severe cases had documented neurologic involvement, and studies of affected children with mild or none of the initial respiratory symptoms of COVID-19 also detected similar selective effects in these brain regions.

A recent survey of medical records of 80 million people that identified 240,000 COVID cases (mostly adults) revealed that a third had neurological and psychiatric sequelae. Dr. Swanson also mentioned an article he wrote more than a decade ago on environmental as well as genetic factors that resulted in etiologic subtypes of ADHD, which provided a model for the impact of COVID-19 on specific brain regions that are associated with ADHD.

So far, the COVID-19 pandemic has produced 150 million cases worldwide and there are about 100 million survivors, setting an estimate of a maximum number of cases with residual sequelae. “I think that severe COVID-19 will probably be related to severe residual sequelae, and that mild or asymptomatic COVID-19 may be associated with less severe residual sequelae, which may resemble ADHD” said Dr. Swanson. If one-third of the cases manifest in some neurologic or psychiatric systems, this means 27 million would have residual sequelae. If 20% have impaired concentration or brain fog, this could result in about 5 million ADHD cases, he said. 
 

Estimates aren’t evidence

The Swanson/Volkow commentary contains a lot of references to “might, could, and may,” said Dr. Coghill. While it’s true that COVID-19 could produce a novel etiologic subtype of ADHD, “the point here is at the moment, all of this is based on hypotheses,” he said.

The Spanish flu did produce mental health consequences – survivors reported depression, sleep disturbances, mental distraction, dizziness, and difficulties coping at work. In the United States, flu death rates from 1918 to 1920 were directly attributed to suicide rates. Unfortunately, these impacts weren’t widely researched, said Dr. Coghill.

It also seems clear that the 1918 Spanish flu outbreak was associated with significant neurological consequences, said Dr. Coghill. By 1919 and 1920, physicians and researchers in the United Kingdom were reporting increases in a variety of symptoms among some patients recovering from flu, such as neuropathy, neurasthenia, meningitis, degenerative changes in nerve cells, and a decline in visual acuity.

The EL cases Dr. Swanson mentioned did coincide with and reach epidemic proportions alongside the Spanish flu. “But still, a causal relationship is far from proven,” said Dr. Coghill.

Sol Levy, MD, described a “disease of criminals” following the 1918 pandemic, in which patients exhibited a high degree of general hyperkinesis, a difficulty in maintaining quiet attitudes, abruptness and clumsiness, and “explosive motor release of all voluntarily inhibited activities.”

However, these impairments suggest a much broader presentation typically seen in ADHD, noted Dr. Coghill.

Neurological complications occur more commonly than initially thought in severe COVID-19, with estimates ranging from 36% to 84%. But in a systematic review of neuropsychiatric complications of severe coronavirus infection, researchers found few psychiatric sequelae of these infections. While they did mention impaired concentration and difficulties with emotional ability, it’s very important to remember that these conditions “are cardinal symptoms of a wide range of psychiatric disorders,” said Dr. Coghill.

Overall, more neurological and neuropsychiatric symptoms largely confine to those with severe COVID-19, meaning they’re much less likely to occur in children and young adults, he said.

If there are severe effects of COVID-19, Dr. Swanson countered that “they might have more ADHD than the complex residual effects [Dr. Coghill] described. I hope that he’s right, but I do think there will be biological co-effects of COVID-19 that will produce symptoms that are more ADHD than other neurological disorders.”
 

Epigenetic effects

Researchers are now seeing transgenerational and intergenerational effects of potential infection. “So I certainly back high-quality studies looking at the effects of maternal and paternal infection on offspring,” said Dr. Coghill. Establishing clinical cohort studies to follow up on this population would be essential in understanding the risks of SARS-CoV-2. “That might be one way we’ll see an increase in ADHD,” said Dr. Coghill.

The reality is COVID-19 hasn’t been around for that long, and current knowledge about it is limited, he said. Rapid publications, cross-sectional or retrospective data, and poor methodological quality and rigor make generalizability difficult. In addition, limited testing and detection probably underestimate prevalence of neurological and neuropsychiatric complications.

“If history teaches us anything, it is that we should always be measured in how we glean lessons from the past. So let’s not get ahead of ourselves,” he cautioned.

An informal, post-discussion survey of session participants revealed that a slight majority – 55%-60% – expected residual effects of COVID-19 to lead to more ADHD, compared to 40%-45% who didn’t think this would happen.

Dr. Swanson has two patents: (PIXA4), which uses a “time-of-flight” camera to measure growth on infants, and a provisional patent on the mechanism of tolerance to stimulant medication (PATSMTA). Dr. Coghill worked for several pharmaceutical companies but had no disclosures relevant to this debate.

While it’s possible that residual effects of SARS-CoV-2 could lead to an eruption of attention-deficit/hyperactivity disorder (ADHD) cases, a debate at the World Congress on ADHD – Virtual Event underscored the fact that this is still a hypothesis. The bottom line is there needs to be more data, said Luis Augusto Rohde, MD, PhD, cochair of the congress’ scientific program committee and moderator of the session, “Residual effects of the 2019 pandemic will mirror the 1918 pandemic: Will we have lots of new ADHD cases?”

Considering the current pattern of the pandemic, there is not enough evidence for this to be a concern, Dr. Rohde said in an interview.

James Swanson, PhD, professor of pediatrics at the University of California, Irvine, opined that biological co-effects of COVID-19 are likely to have selective effects in children that may produce symptoms representative of ADHD. Using the 1918 Spanish flu pandemic as a historical reference, he estimated that COVID-19 would produce 5 million individuals with new-onset symptoms related to ADHD. “If these cases meet DSM-5 or ICD-11 criteria, there will be lots of new ADHD cases,” he predicted.

David Coghill, MD, a professor of child adolescent mental health at the University of Melbourne, observed that the sums Dr. Swanson presented “are based on maxing out the potential rather than looking at the sums more realistically.”
 

Could the 1918 pandemic offer clues?

In a commentary, Dr. Swanson and Nora D. Volkow, MD, wrote about “lessons learned” from the 1918 pandemic, and how residual sequelae in that era led to a condition labeled hyperkinetic syndrome in children. “It may be worthwhile to consider the hypothesis that the COVID-19 pandemic may result in a novel etiologic subtype of ADHD that clinicians may recognize in patients in the future,” wrote the commentators. 

In survivors of the 1918 pandemic, brain inflammation or encephalitis sometimes emerged as residual sequelae, said Dr. Swanson. In some adult cases, these symptoms were diagnosed as “encephalitis lethargica” (EL) and were associated with Parkinson’s disease. In 1930, based on patients evaluated after 1918, researchers Franz Kramer and Hans Pollnow at Charité Hospital in Berlin described the behavioral manifestation of EL in children as hyperkinetic syndrome, a condition that was characterized by symptoms similar to the properties of ADHD: lack of concentration, insufficient goal orientation, and increased distractibility. “They even reported on autopsy cases that described brain regions that we now know are associated with ADHD from decades of brain imaging studies,” said Dr. Swanson.

COVID-19 rarely results in severe respiratory problems in children but the absolute number requiring hospitalization has accumulated and is now relatively large, said Dr. Swanson. One study of 1,695 severe COVID-19 cases in children and adolescents used MRI and detected neural effects in specific brain regions such as basal ganglia and frontal lobes that previous research had associated with ADHD. Approximately 22% of these rare but severe cases had documented neurologic involvement, and studies of affected children with mild or none of the initial respiratory symptoms of COVID-19 also detected similar selective effects in these brain regions.

A recent survey of medical records of 80 million people that identified 240,000 COVID cases (mostly adults) revealed that a third had neurological and psychiatric sequelae. Dr. Swanson also mentioned an article he wrote more than a decade ago on environmental as well as genetic factors that resulted in etiologic subtypes of ADHD, which provided a model for the impact of COVID-19 on specific brain regions that are associated with ADHD.

So far, the COVID-19 pandemic has produced 150 million cases worldwide and there are about 100 million survivors, setting an estimate of a maximum number of cases with residual sequelae. “I think that severe COVID-19 will probably be related to severe residual sequelae, and that mild or asymptomatic COVID-19 may be associated with less severe residual sequelae, which may resemble ADHD” said Dr. Swanson. If one-third of the cases manifest in some neurologic or psychiatric systems, this means 27 million would have residual sequelae. If 20% have impaired concentration or brain fog, this could result in about 5 million ADHD cases, he said. 
 

Estimates aren’t evidence

The Swanson/Volkow commentary contains a lot of references to “might, could, and may,” said Dr. Coghill. While it’s true that COVID-19 could produce a novel etiologic subtype of ADHD, “the point here is at the moment, all of this is based on hypotheses,” he said.

The Spanish flu did produce mental health consequences – survivors reported depression, sleep disturbances, mental distraction, dizziness, and difficulties coping at work. In the United States, flu death rates from 1918 to 1920 were directly attributed to suicide rates. Unfortunately, these impacts weren’t widely researched, said Dr. Coghill.

It also seems clear that the 1918 Spanish flu outbreak was associated with significant neurological consequences, said Dr. Coghill. By 1919 and 1920, physicians and researchers in the United Kingdom were reporting increases in a variety of symptoms among some patients recovering from flu, such as neuropathy, neurasthenia, meningitis, degenerative changes in nerve cells, and a decline in visual acuity.

The EL cases Dr. Swanson mentioned did coincide with and reach epidemic proportions alongside the Spanish flu. “But still, a causal relationship is far from proven,” said Dr. Coghill.

Sol Levy, MD, described a “disease of criminals” following the 1918 pandemic, in which patients exhibited a high degree of general hyperkinesis, a difficulty in maintaining quiet attitudes, abruptness and clumsiness, and “explosive motor release of all voluntarily inhibited activities.”

However, these impairments suggest a much broader presentation typically seen in ADHD, noted Dr. Coghill.

Neurological complications occur more commonly than initially thought in severe COVID-19, with estimates ranging from 36% to 84%. But in a systematic review of neuropsychiatric complications of severe coronavirus infection, researchers found few psychiatric sequelae of these infections. While they did mention impaired concentration and difficulties with emotional ability, it’s very important to remember that these conditions “are cardinal symptoms of a wide range of psychiatric disorders,” said Dr. Coghill.

Overall, more neurological and neuropsychiatric symptoms largely confine to those with severe COVID-19, meaning they’re much less likely to occur in children and young adults, he said.

If there are severe effects of COVID-19, Dr. Swanson countered that “they might have more ADHD than the complex residual effects [Dr. Coghill] described. I hope that he’s right, but I do think there will be biological co-effects of COVID-19 that will produce symptoms that are more ADHD than other neurological disorders.”
 

Epigenetic effects

Researchers are now seeing transgenerational and intergenerational effects of potential infection. “So I certainly back high-quality studies looking at the effects of maternal and paternal infection on offspring,” said Dr. Coghill. Establishing clinical cohort studies to follow up on this population would be essential in understanding the risks of SARS-CoV-2. “That might be one way we’ll see an increase in ADHD,” said Dr. Coghill.

The reality is COVID-19 hasn’t been around for that long, and current knowledge about it is limited, he said. Rapid publications, cross-sectional or retrospective data, and poor methodological quality and rigor make generalizability difficult. In addition, limited testing and detection probably underestimate prevalence of neurological and neuropsychiatric complications.

“If history teaches us anything, it is that we should always be measured in how we glean lessons from the past. So let’s not get ahead of ourselves,” he cautioned.

An informal, post-discussion survey of session participants revealed that a slight majority – 55%-60% – expected residual effects of COVID-19 to lead to more ADHD, compared to 40%-45% who didn’t think this would happen.

Dr. Swanson has two patents: (PIXA4), which uses a “time-of-flight” camera to measure growth on infants, and a provisional patent on the mechanism of tolerance to stimulant medication (PATSMTA). Dr. Coghill worked for several pharmaceutical companies but had no disclosures relevant to this debate.

While it’s possible that residual effects of SARS-CoV-2 could lead to an eruption of attention-deficit/hyperactivity disorder (ADHD) cases, a debate at the World Congress on ADHD – Virtual Event underscored the fact that this is still a hypothesis. The bottom line is there needs to be more data, said Luis Augusto Rohde, MD, PhD, cochair of the congress’ scientific program committee and moderator of the session, “Residual effects of the 2019 pandemic will mirror the 1918 pandemic: Will we have lots of new ADHD cases?”

Considering the current pattern of the pandemic, there is not enough evidence for this to be a concern, Dr. Rohde said in an interview.

James Swanson, PhD, professor of pediatrics at the University of California, Irvine, opined that biological co-effects of COVID-19 are likely to have selective effects in children that may produce symptoms representative of ADHD. Using the 1918 Spanish flu pandemic as a historical reference, he estimated that COVID-19 would produce 5 million individuals with new-onset symptoms related to ADHD. “If these cases meet DSM-5 or ICD-11 criteria, there will be lots of new ADHD cases,” he predicted.

David Coghill, MD, a professor of child adolescent mental health at the University of Melbourne, observed that the sums Dr. Swanson presented “are based on maxing out the potential rather than looking at the sums more realistically.”
 

Could the 1918 pandemic offer clues?

In a commentary, Dr. Swanson and Nora D. Volkow, MD, wrote about “lessons learned” from the 1918 pandemic, and how residual sequelae in that era led to a condition labeled hyperkinetic syndrome in children. “It may be worthwhile to consider the hypothesis that the COVID-19 pandemic may result in a novel etiologic subtype of ADHD that clinicians may recognize in patients in the future,” wrote the commentators. 

In survivors of the 1918 pandemic, brain inflammation or encephalitis sometimes emerged as residual sequelae, said Dr. Swanson. In some adult cases, these symptoms were diagnosed as “encephalitis lethargica” (EL) and were associated with Parkinson’s disease. In 1930, based on patients evaluated after 1918, researchers Franz Kramer and Hans Pollnow at Charité Hospital in Berlin described the behavioral manifestation of EL in children as hyperkinetic syndrome, a condition that was characterized by symptoms similar to the properties of ADHD: lack of concentration, insufficient goal orientation, and increased distractibility. “They even reported on autopsy cases that described brain regions that we now know are associated with ADHD from decades of brain imaging studies,” said Dr. Swanson.

COVID-19 rarely results in severe respiratory problems in children but the absolute number requiring hospitalization has accumulated and is now relatively large, said Dr. Swanson. One study of 1,695 severe COVID-19 cases in children and adolescents used MRI and detected neural effects in specific brain regions such as basal ganglia and frontal lobes that previous research had associated with ADHD. Approximately 22% of these rare but severe cases had documented neurologic involvement, and studies of affected children with mild or none of the initial respiratory symptoms of COVID-19 also detected similar selective effects in these brain regions.

A recent survey of medical records of 80 million people that identified 240,000 COVID cases (mostly adults) revealed that a third had neurological and psychiatric sequelae. Dr. Swanson also mentioned an article he wrote more than a decade ago on environmental as well as genetic factors that resulted in etiologic subtypes of ADHD, which provided a model for the impact of COVID-19 on specific brain regions that are associated with ADHD.

So far, the COVID-19 pandemic has produced 150 million cases worldwide and there are about 100 million survivors, setting an estimate of a maximum number of cases with residual sequelae. “I think that severe COVID-19 will probably be related to severe residual sequelae, and that mild or asymptomatic COVID-19 may be associated with less severe residual sequelae, which may resemble ADHD” said Dr. Swanson. If one-third of the cases manifest in some neurologic or psychiatric systems, this means 27 million would have residual sequelae. If 20% have impaired concentration or brain fog, this could result in about 5 million ADHD cases, he said. 
 

Estimates aren’t evidence

The Swanson/Volkow commentary contains a lot of references to “might, could, and may,” said Dr. Coghill. While it’s true that COVID-19 could produce a novel etiologic subtype of ADHD, “the point here is at the moment, all of this is based on hypotheses,” he said.

The Spanish flu did produce mental health consequences – survivors reported depression, sleep disturbances, mental distraction, dizziness, and difficulties coping at work. In the United States, flu death rates from 1918 to 1920 were directly attributed to suicide rates. Unfortunately, these impacts weren’t widely researched, said Dr. Coghill.

It also seems clear that the 1918 Spanish flu outbreak was associated with significant neurological consequences, said Dr. Coghill. By 1919 and 1920, physicians and researchers in the United Kingdom were reporting increases in a variety of symptoms among some patients recovering from flu, such as neuropathy, neurasthenia, meningitis, degenerative changes in nerve cells, and a decline in visual acuity.

The EL cases Dr. Swanson mentioned did coincide with and reach epidemic proportions alongside the Spanish flu. “But still, a causal relationship is far from proven,” said Dr. Coghill.

Sol Levy, MD, described a “disease of criminals” following the 1918 pandemic, in which patients exhibited a high degree of general hyperkinesis, a difficulty in maintaining quiet attitudes, abruptness and clumsiness, and “explosive motor release of all voluntarily inhibited activities.”

However, these impairments suggest a much broader presentation typically seen in ADHD, noted Dr. Coghill.

Neurological complications occur more commonly than initially thought in severe COVID-19, with estimates ranging from 36% to 84%. But in a systematic review of neuropsychiatric complications of severe coronavirus infection, researchers found few psychiatric sequelae of these infections. While they did mention impaired concentration and difficulties with emotional ability, it’s very important to remember that these conditions “are cardinal symptoms of a wide range of psychiatric disorders,” said Dr. Coghill.

Overall, more neurological and neuropsychiatric symptoms largely confine to those with severe COVID-19, meaning they’re much less likely to occur in children and young adults, he said.

If there are severe effects of COVID-19, Dr. Swanson countered that “they might have more ADHD than the complex residual effects [Dr. Coghill] described. I hope that he’s right, but I do think there will be biological co-effects of COVID-19 that will produce symptoms that are more ADHD than other neurological disorders.”
 

Epigenetic effects

Researchers are now seeing transgenerational and intergenerational effects of potential infection. “So I certainly back high-quality studies looking at the effects of maternal and paternal infection on offspring,” said Dr. Coghill. Establishing clinical cohort studies to follow up on this population would be essential in understanding the risks of SARS-CoV-2. “That might be one way we’ll see an increase in ADHD,” said Dr. Coghill.

The reality is COVID-19 hasn’t been around for that long, and current knowledge about it is limited, he said. Rapid publications, cross-sectional or retrospective data, and poor methodological quality and rigor make generalizability difficult. In addition, limited testing and detection probably underestimate prevalence of neurological and neuropsychiatric complications.

“If history teaches us anything, it is that we should always be measured in how we glean lessons from the past. So let’s not get ahead of ourselves,” he cautioned.

An informal, post-discussion survey of session participants revealed that a slight majority – 55%-60% – expected residual effects of COVID-19 to lead to more ADHD, compared to 40%-45% who didn’t think this would happen.

Dr. Swanson has two patents: (PIXA4), which uses a “time-of-flight” camera to measure growth on infants, and a provisional patent on the mechanism of tolerance to stimulant medication (PATSMTA). Dr. Coghill worked for several pharmaceutical companies but had no disclosures relevant to this debate.

For children with attention-deficit/hyperactivity disorder, taking a weekend or summer break from methylphenidate may have some benefits. A drug “holiday” can help assess whether a drug is still useful and possibly help with drug tolerance, weight gain, and growth suppression. But drug holidays are not without their problems, Lily Hechtman, MD, FRCP, professor at the department of psychiatry, McGill University, Montreal, said during a session at the World Congress on ADHD – Virtual Event.

Ceasing a medication can have repercussions from a health and social standpoint, cautioned Dr. Hechtman, a presenter and moderator of the session, “Unsolved mysteries in the treatment of ADHD with psychostimulants.”

The rate of drug holidays is somewhere between 30% and 40% in ADHD patients. Patients have multiple reasons for taking them, said Dr. Hechtman. The American Academy of Child & Adolescent Psychology as well as the National Institute for Health and Clinical Excellence recommend this method to assess whether a medication is still necessary. Parents may opt for a drug holiday because most would prefer their children to take less medication.

A drug holiday can counteract some of the key side effects of stimulant medication such as decreased appetite and weight loss, and the moodiness and irritability that accompanies the medication, as well as sleep problems.

It may also be used to avoid drug tolerance, the need to increase dosage as medication continues. A 2002 study of 166 children and adolescents treated with methylphenidate revealed that 60% had developed drug tolerance. Drug tolerance increases with duration. “So, the longer the child is on medication, the more likely he or she will develop some drug tolerance,” said Dr. Hechtman.

It is hypothesized that a drug holiday results in the resensitization of the neurons in the brain because they aren’t exposed to the stimulation of dopamine release and dopamine exposure.

The minimum time a patient needs a drug holiday to deal with some drug tolerance is about a month. “Even if you have a drug holiday and your drug tolerance has been decreased, it can reoccur with increasing dosages, once medication resumes” after the holiday, said Dr. Hechtman.
 

The growth factor

A drug holiday can also address concerns about growth suppression. “Some studies show that drug holidays help with growth suppression and others do not,” said Dr. Hechtman.

The Multimodal Treatment of ADHD (MTA) study, which followed children with ADHD from childhood to adolescence into adulthood, offers some key insights on the effects of treatment on growth.

Over a 10-year period, “you could see that the rate of medication use decreased significantly with time” among participants, said Dr. Hechtman, a coauthor of the MTA research. Only 10% who began the study aged 7-9 years were still using stimulants 10 years later. Looking at short-term effects on growth among these children, those who never went on stimulants to begin with had no growth suppression at all, whereas those who underwent early and consistent treatment experienced the greatest growth suppression.

Comparatively, inconsistently medicated participants had less growth suppression than those who remained on medication. “They were pretty close to the controls,” said Dr. Hechtman.

These patterns continued in a 16-year follow-up, as these patients became adults. Based on the results in the inconsistently treated group, this suggests that drug holidays can limit the effects of growth suppression, at least to a certain extent, said Dr. Hechtman.

Other studies have yielded varying results on the impact of drug holidays on height and weight. “The evidence for the utility of drug holidays for medication side effects is there for decreased appetite and weight, but not so much for decreased height,” summarized Dr. Hechtman.

One recent study of 230 children by James Waxmonsky and colleagues that examined drug holidays on weekends and summers showed that drug holidays did increase weight but interestingly, not height. Older studies Dr. Hechtman cited had inconsistent results on height and weight gain and loss. A 2012 study suggested that drug holidays resulted in a slight improvement in appetite for both weekend and school holidays. But only 9% of the children in the sample (n = 51) saw their appetite return to normal levels.
 

‘Negative things can happen’

The downside of drug holidays is parents may rationalize that their child is doing fine without the medication, and discontinue it. The process of stopping and starting medication can lead to other problems. “Negative things can happen during drug holidays,” said Dr. Hechtman.

The large variability of doses over the weekend can result in rebound and side effects.

A child may go from a full dose, which could be 50-60 mg of stimulant to zero from Friday to Saturday. As a result they have a lot of rebound on that Saturday. Similarly, they go from zero on Sunday to full dose on the Monday, causing lots of side effects. “Also, they will never have a stable effective dose because of the roller-coaster effect of being on and off the drugs,” she noted.

The lack of consistency and accommodation to the side effects can lead to discontinuation of the medication.

Off medication, the child may be more accident prone or have more injuries. “Their behavior off the medication may be such that it leads to social problems,” Dr. Hechtman continued. Weekend activities that require medication such as homework or school projects, family or religious gatherings, or sports and social activities with family and peers may be affected. If the child is behaving poorly off the medication, they may be expelled from such activities. If it’s a summer drug holiday, they may get kicked out of camp or the swimming pool.

If the child’s condition is already worsening, and a drug holiday takes place on top of this, the child may experience a rebound or relapse, in which the condition looks a lot worse than it did with the drugs.
 

Do drug holidays matter?

Another session speaker, James Swanson, PhD, who noted that the “emergence of tolerance may limit and eventually undermine initial relative benefit” of stimulants, said there may be instances in which drug holidays may be impractical.

Given the poor adherence to ADHD medication, “most treated ADHD cases stop medication anyway and these patients do not have an opportunity for drug holidays,” he said in an interview.

“If tolerance does emerge, then for long-term treatment the concept of drug holiday seems difficult to evaluate to me,” said Dr. Swanson, director of the Child Development Center at the University of California, Irvine.

Planned medication breaks may not be a good way to evaluate efficacy unless it is performed under “double-blind” conditions, he offered. The MTA used an approach of switching between short periods of time, with and without medication. “We did this to compare medication to placebo and to compare doses of medication to optimize the short-term benefit,” said Dr. Swanson, a coauthor of the MTA study.

Dr. Hechtman receives funding from The Canadian Institutes of Health Research. Dr. Swanson has two patents: (PIXA4), which uses a “time-of-flight” camera to measure growth on infants, and a provisional patent on the mechanism of tolerance to stimulant medication (PATSMTA).

For children with attention-deficit/hyperactivity disorder, taking a weekend or summer break from methylphenidate may have some benefits. A drug “holiday” can help assess whether a drug is still useful and possibly help with drug tolerance, weight gain, and growth suppression. But drug holidays are not without their problems, Lily Hechtman, MD, FRCP, professor at the department of psychiatry, McGill University, Montreal, said during a session at the World Congress on ADHD – Virtual Event.

Ceasing a medication can have repercussions from a health and social standpoint, cautioned Dr. Hechtman, a presenter and moderator of the session, “Unsolved mysteries in the treatment of ADHD with psychostimulants.”

The rate of drug holidays is somewhere between 30% and 40% in ADHD patients. Patients have multiple reasons for taking them, said Dr. Hechtman. The American Academy of Child & Adolescent Psychology as well as the National Institute for Health and Clinical Excellence recommend this method to assess whether a medication is still necessary. Parents may opt for a drug holiday because most would prefer their children to take less medication.

A drug holiday can counteract some of the key side effects of stimulant medication such as decreased appetite and weight loss, and the moodiness and irritability that accompanies the medication, as well as sleep problems.

It may also be used to avoid drug tolerance, the need to increase dosage as medication continues. A 2002 study of 166 children and adolescents treated with methylphenidate revealed that 60% had developed drug tolerance. Drug tolerance increases with duration. “So, the longer the child is on medication, the more likely he or she will develop some drug tolerance,” said Dr. Hechtman.

It is hypothesized that a drug holiday results in the resensitization of the neurons in the brain because they aren’t exposed to the stimulation of dopamine release and dopamine exposure.

The minimum time a patient needs a drug holiday to deal with some drug tolerance is about a month. “Even if you have a drug holiday and your drug tolerance has been decreased, it can reoccur with increasing dosages, once medication resumes” after the holiday, said Dr. Hechtman.
 

The growth factor

A drug holiday can also address concerns about growth suppression. “Some studies show that drug holidays help with growth suppression and others do not,” said Dr. Hechtman.

The Multimodal Treatment of ADHD (MTA) study, which followed children with ADHD from childhood to adolescence into adulthood, offers some key insights on the effects of treatment on growth.

Over a 10-year period, “you could see that the rate of medication use decreased significantly with time” among participants, said Dr. Hechtman, a coauthor of the MTA research. Only 10% who began the study aged 7-9 years were still using stimulants 10 years later. Looking at short-term effects on growth among these children, those who never went on stimulants to begin with had no growth suppression at all, whereas those who underwent early and consistent treatment experienced the greatest growth suppression.

Comparatively, inconsistently medicated participants had less growth suppression than those who remained on medication. “They were pretty close to the controls,” said Dr. Hechtman.

These patterns continued in a 16-year follow-up, as these patients became adults. Based on the results in the inconsistently treated group, this suggests that drug holidays can limit the effects of growth suppression, at least to a certain extent, said Dr. Hechtman.

Other studies have yielded varying results on the impact of drug holidays on height and weight. “The evidence for the utility of drug holidays for medication side effects is there for decreased appetite and weight, but not so much for decreased height,” summarized Dr. Hechtman.

One recent study of 230 children by James Waxmonsky and colleagues that examined drug holidays on weekends and summers showed that drug holidays did increase weight but interestingly, not height. Older studies Dr. Hechtman cited had inconsistent results on height and weight gain and loss. A 2012 study suggested that drug holidays resulted in a slight improvement in appetite for both weekend and school holidays. But only 9% of the children in the sample (n = 51) saw their appetite return to normal levels.
 

‘Negative things can happen’

The downside of drug holidays is parents may rationalize that their child is doing fine without the medication, and discontinue it. The process of stopping and starting medication can lead to other problems. “Negative things can happen during drug holidays,” said Dr. Hechtman.

The large variability of doses over the weekend can result in rebound and side effects.

A child may go from a full dose, which could be 50-60 mg of stimulant to zero from Friday to Saturday. As a result they have a lot of rebound on that Saturday. Similarly, they go from zero on Sunday to full dose on the Monday, causing lots of side effects. “Also, they will never have a stable effective dose because of the roller-coaster effect of being on and off the drugs,” she noted.

The lack of consistency and accommodation to the side effects can lead to discontinuation of the medication.

Off medication, the child may be more accident prone or have more injuries. “Their behavior off the medication may be such that it leads to social problems,” Dr. Hechtman continued. Weekend activities that require medication such as homework or school projects, family or religious gatherings, or sports and social activities with family and peers may be affected. If the child is behaving poorly off the medication, they may be expelled from such activities. If it’s a summer drug holiday, they may get kicked out of camp or the swimming pool.

If the child’s condition is already worsening, and a drug holiday takes place on top of this, the child may experience a rebound or relapse, in which the condition looks a lot worse than it did with the drugs.
 

Do drug holidays matter?

Another session speaker, James Swanson, PhD, who noted that the “emergence of tolerance may limit and eventually undermine initial relative benefit” of stimulants, said there may be instances in which drug holidays may be impractical.

Given the poor adherence to ADHD medication, “most treated ADHD cases stop medication anyway and these patients do not have an opportunity for drug holidays,” he said in an interview.

“If tolerance does emerge, then for long-term treatment the concept of drug holiday seems difficult to evaluate to me,” said Dr. Swanson, director of the Child Development Center at the University of California, Irvine.

Planned medication breaks may not be a good way to evaluate efficacy unless it is performed under “double-blind” conditions, he offered. The MTA used an approach of switching between short periods of time, with and without medication. “We did this to compare medication to placebo and to compare doses of medication to optimize the short-term benefit,” said Dr. Swanson, a coauthor of the MTA study.

Dr. Hechtman receives funding from The Canadian Institutes of Health Research. Dr. Swanson has two patents: (PIXA4), which uses a “time-of-flight” camera to measure growth on infants, and a provisional patent on the mechanism of tolerance to stimulant medication (PATSMTA).

For children with attention-deficit/hyperactivity disorder, taking a weekend or summer break from methylphenidate may have some benefits. A drug “holiday” can help assess whether a drug is still useful and possibly help with drug tolerance, weight gain, and growth suppression. But drug holidays are not without their problems, Lily Hechtman, MD, FRCP, professor at the department of psychiatry, McGill University, Montreal, said during a session at the World Congress on ADHD – Virtual Event.

Ceasing a medication can have repercussions from a health and social standpoint, cautioned Dr. Hechtman, a presenter and moderator of the session, “Unsolved mysteries in the treatment of ADHD with psychostimulants.”

The rate of drug holidays is somewhere between 30% and 40% in ADHD patients. Patients have multiple reasons for taking them, said Dr. Hechtman. The American Academy of Child & Adolescent Psychology as well as the National Institute for Health and Clinical Excellence recommend this method to assess whether a medication is still necessary. Parents may opt for a drug holiday because most would prefer their children to take less medication.

A drug holiday can counteract some of the key side effects of stimulant medication such as decreased appetite and weight loss, and the moodiness and irritability that accompanies the medication, as well as sleep problems.

It may also be used to avoid drug tolerance, the need to increase dosage as medication continues. A 2002 study of 166 children and adolescents treated with methylphenidate revealed that 60% had developed drug tolerance. Drug tolerance increases with duration. “So, the longer the child is on medication, the more likely he or she will develop some drug tolerance,” said Dr. Hechtman.

It is hypothesized that a drug holiday results in the resensitization of the neurons in the brain because they aren’t exposed to the stimulation of dopamine release and dopamine exposure.

The minimum time a patient needs a drug holiday to deal with some drug tolerance is about a month. “Even if you have a drug holiday and your drug tolerance has been decreased, it can reoccur with increasing dosages, once medication resumes” after the holiday, said Dr. Hechtman.
 

The growth factor

A drug holiday can also address concerns about growth suppression. “Some studies show that drug holidays help with growth suppression and others do not,” said Dr. Hechtman.

The Multimodal Treatment of ADHD (MTA) study, which followed children with ADHD from childhood to adolescence into adulthood, offers some key insights on the effects of treatment on growth.

Over a 10-year period, “you could see that the rate of medication use decreased significantly with time” among participants, said Dr. Hechtman, a coauthor of the MTA research. Only 10% who began the study aged 7-9 years were still using stimulants 10 years later. Looking at short-term effects on growth among these children, those who never went on stimulants to begin with had no growth suppression at all, whereas those who underwent early and consistent treatment experienced the greatest growth suppression.

Comparatively, inconsistently medicated participants had less growth suppression than those who remained on medication. “They were pretty close to the controls,” said Dr. Hechtman.

These patterns continued in a 16-year follow-up, as these patients became adults. Based on the results in the inconsistently treated group, this suggests that drug holidays can limit the effects of growth suppression, at least to a certain extent, said Dr. Hechtman.

Other studies have yielded varying results on the impact of drug holidays on height and weight. “The evidence for the utility of drug holidays for medication side effects is there for decreased appetite and weight, but not so much for decreased height,” summarized Dr. Hechtman.

One recent study of 230 children by James Waxmonsky and colleagues that examined drug holidays on weekends and summers showed that drug holidays did increase weight but interestingly, not height. Older studies Dr. Hechtman cited had inconsistent results on height and weight gain and loss. A 2012 study suggested that drug holidays resulted in a slight improvement in appetite for both weekend and school holidays. But only 9% of the children in the sample (n = 51) saw their appetite return to normal levels.
 

‘Negative things can happen’

The downside of drug holidays is parents may rationalize that their child is doing fine without the medication, and discontinue it. The process of stopping and starting medication can lead to other problems. “Negative things can happen during drug holidays,” said Dr. Hechtman.

The large variability of doses over the weekend can result in rebound and side effects.

A child may go from a full dose, which could be 50-60 mg of stimulant to zero from Friday to Saturday. As a result they have a lot of rebound on that Saturday. Similarly, they go from zero on Sunday to full dose on the Monday, causing lots of side effects. “Also, they will never have a stable effective dose because of the roller-coaster effect of being on and off the drugs,” she noted.

The lack of consistency and accommodation to the side effects can lead to discontinuation of the medication.

Off medication, the child may be more accident prone or have more injuries. “Their behavior off the medication may be such that it leads to social problems,” Dr. Hechtman continued. Weekend activities that require medication such as homework or school projects, family or religious gatherings, or sports and social activities with family and peers may be affected. If the child is behaving poorly off the medication, they may be expelled from such activities. If it’s a summer drug holiday, they may get kicked out of camp or the swimming pool.

If the child’s condition is already worsening, and a drug holiday takes place on top of this, the child may experience a rebound or relapse, in which the condition looks a lot worse than it did with the drugs.
 

Do drug holidays matter?

Another session speaker, James Swanson, PhD, who noted that the “emergence of tolerance may limit and eventually undermine initial relative benefit” of stimulants, said there may be instances in which drug holidays may be impractical.

Given the poor adherence to ADHD medication, “most treated ADHD cases stop medication anyway and these patients do not have an opportunity for drug holidays,” he said in an interview.

“If tolerance does emerge, then for long-term treatment the concept of drug holiday seems difficult to evaluate to me,” said Dr. Swanson, director of the Child Development Center at the University of California, Irvine.

Planned medication breaks may not be a good way to evaluate efficacy unless it is performed under “double-blind” conditions, he offered. The MTA used an approach of switching between short periods of time, with and without medication. “We did this to compare medication to placebo and to compare doses of medication to optimize the short-term benefit,” said Dr. Swanson, a coauthor of the MTA study.

Dr. Hechtman receives funding from The Canadian Institutes of Health Research. Dr. Swanson has two patents: (PIXA4), which uses a “time-of-flight” camera to measure growth on infants, and a provisional patent on the mechanism of tolerance to stimulant medication (PATSMTA).

New digital tools are on the horizon to help patients with attention-deficit/hyperactivity disorder (ADHD) manage the condition.

Rostislav_Sedlacek/Thinkstock

Speakers at the World Congress on ADHD – Virtual Event described innovations aimed at improving medication compliance or reducing symptoms through the use of smartphone technology such as apps and text messaging, and video games. Some of these technologies have shown promising results in clinical trials, but the experts called for additional studies to further vet their efficacy.

An explosion in technology

ADHD, the most common neurodevelopmental disorder, has global prevalence rates ranging from 5% to 7%, said Dr. Kirk. Digital technology and digital health “have been heralded as having enormous potential to improve early access and to improve the increasing demand in child support services,” she said.

The world has seen an explosion of digital technology innovation in the last decade, spurred on most recently by the COVID-19 pandemic. New demand exists for tools in educational and health care settings to provide information and support through websites, apps, SMS, video conferencing, and wearable devices, Dr. Kirk said.

Looking at the landscape of ADHD digital therapeutics, “there are probably tens of thousands of apps and other digital products to treat and manage conditions across the spectrum,” said Scott H. Kollins, PhD, MS, a clinical psychologist at Duke Health’s ADHD Clinic in Durham, N.C.

Video game interventions

AKL-T01, a tool that pairs continuous fine motor tasks and perceptual reaction time tasks, went through several rounds of clinical trials to achieve federal approval as a digital therapeutic.

“This not just another video game,” said Dr. Kollins, who helped developed it. The tool’s adaptive algorithms adjust and monitor task difficulty based on performance, using a video game format and rewards to engage users.

Two phase 3 trials provided the basis for the Food and Drug Administration’s approval of AKL-T01, also known as EndeavorRx, in 2020. The first trial, published in The Lancet, randomized 348 children 1:1 to receive either the AKL-T01 treatment or a controlled intervention, which was a word game. Participating children aged 8-12 with a confirmed ADHD diagnosis were asked to play the game for about 25 minutes a day, 5 days a week over 4 weeks. The study excluded children who were taking medicine.

The researchers reported statistically significant improvements in attentional functioning in the AKL-T01 group as rated by test of variables of attention. The trial reported no serious adverse events, although one child in the AKL-T01 group withdrew from the study.

“As kids go through this treatment, it’s challenging and the difficulty levels increase, so it’s not surprising that kids get frustrated with that, or have emotional outbursts,” Dr. Kollins said. Those reactions suggest that the intervention was working, he added.

A follow-up study, published in npj Digital Medicine, broadened the scope. That study included children who had taken medication and extended the study period. Overall, 206 children aged 8-14 (130 on stimulants and 76 on no medication) played the game for 28 days, taking a pause for another 28 days, then reinitiating the treatment.

As in the first trial, AKL-T01 significantly improved ADHD-related impairment, a metric that continued to improve in the second round of treatment. Looking at secondary outcomes, the proportion of children deemed as clinical responders on the Impairment Rating Scale, 68.3% of all of the participants were responders by the end of the study on the ADHD ratings scale, meaning there was a greater than 30% improvement in symptoms. Upward of 50% of participants at the end of the second round of treatment showed substantial improvement in their ADHD ratings scale scores.

“This was really a substantial move ... the first-ever app-based video game approved by the FDA,” noted Dr. Kollins, who is affiliated with the Duke Clinical Research Institute. Some skeptics have called this a marketing ploy or have questioned the integrity of the FDA approval process.

“I would submit and argue that the rigor of the trial speaks for itself,” he said. “But it’s not surprising that there’s skepticism in the clinical community about something like this – a brand new treatment modality.”

In her own research, Dr. Kirk has studied game-based interventions aimed at assessing ADHD and improving cognitive training. In 2018, her team developed a touch screen game–based intervention for early evaluation of attention skills, using six activities. In a visual search task, children were asked to locate red lobsters on a screen that showed a variety of underwater creatures. In another selection attention task, children were asked to scan the screen for a particular target, such as a yellow star, and to indicate whether that target was absent or present on the screen. Other tasks assessed for sustained attention abilities and information processing speed.

She and her colleagues recruited 340 children aged 4-7 years to evaluate whether the tool produced consistent results over time, and compared favorably to existing measures of attention. None of the participants had been diagnosed with ADHD. To assess reliability, a subset of children completed another assessment 2 weeks after the first one. The study showed varying results according to activity. The visual search task had high test-retest reliability and the strongest validity, compared with the other tasks. The sustained attention tasks exhibited the weakest validity.

The next steps are to assess whether this tool is sensitive enough to detect differences between children with or without clinical attention difficulties such as ADHD, Dr. Kirk said.

Apps improve adherence

As some technologies focus on reducing symptoms through games, others seek to improve medication compliance through SMS and smartphone apps.

Studies have shown that medication can decrease incidence of smoking, mood disorders, traumatic brain injuries, car crashes, and educational outcomes. However, risk decreases only if compliance is good, said Joseph Biederman, MD. Right now, “there’s extremely poor adherence to stimulant medications in ADHD” across the world, said Dr. Biederman, chief of clinical and research programs in pediatric psychopharmacology and adult ADHD at Massachusetts General Hospital in Boston.

“This is a problem that’s driven by ADHD itself,” he continued. Prescribers don’t always have the time to educate the patient on medications, deal with misconceptions, or provide support for management of daily activities.

Text reminders may offer a solution. Partnering with a Canadian technology company, MEMOTEXT, Dr. Biederman and colleagues at Massachusetts General Hospital developed an SMS-based disease management intervention for ADHD.

The tool aims to manage work, home life, and social relationships by supporting the timely renewal of medications. It doesn’t just remind people to take their ADHD medication, it reminds them to take any other medication they need, and provides the reasons why it’s important to take these drugs. Through interactive questions, it also assesses the progress and knowledge of patients and families about ADHD.

Testing this app in pediatric settings, Dr. Biederman and colleagues published a study in the Journal of Psychopharmacology showing a dramatic increase in compliance – from 60% to 90%.

In another study, this one published in the Journal of Clinical Psychopharmacology, Dr. Biederman and colleagues found that compliance improved, from 35% to 70% in adults. The SMS program in these settings not only improved adherence, but it also reduced costs of ADHD-associated complications while adding beneficial support and value to patients, families, and prescribers, Dr. Biederman said.

Promising findings about the power of apps to increase ADHD medication adherence led Luis Augusto Rohde, MD, PhD, and colleagues to develop the FOCUS app in 2016, for use in his home country of Brazil. The app objectively monitors symptoms of ADHD and establishes cooperative relationships between the patient, their families, and caregivers, said Dr. Rohde, professor of child and adolescent psychiatry at the Federal University of Rio Grande do Sul’s department of psychiatry, Porto Alegre, Brazil.

Digital tech pros and cons

The accessibility of digital technology to children living in remote areas is one of its biggest assets, Dr. Kirk said.

Digital technologies capture real time data, are easy to use, are suitable for young children with developmental disorders, have few adverse effects, and can be easily updated. However, there are some limitations, she added. Attitudes toward technology, time required to supervise their use, and funding to facilitate the use of such technology can hinder implementation. Given that digital technology is increasingly being used to collect sensitive medical data and assess clinical conditions, it’s crucial for these new technologies to be compliant with HIPAA requirements, Dr. Kirk said.

“We are at the front end of a revolution, and much more of this is coming down the pike,” Dr. Kollins predicted. Developers need to be thoughtful and deliberate in how they design clinical evidence strategies for digital therapeutics for ADHD.

“There’s much work that needs to be done from a clinical, statistical, regulatory, and policy perspective, but this journey illustrates this can be done with ADHD and other mental health conditions.”

Dr. Kirk disclosed working previously for a small technology company in Melbourne that developed medical technologies for children. Dr. Kollins’ work has been supported by numerous U.S. agencies, including the National Institute of Mental Health. He has served as a consultant to numerous pharmaceutical companies tied to ADHD clinical psychopharmacology. Dr. Biederman has provided research support to Genentech, Headspace, Pfizer, Roche Translational & Clinical Research Center, and other pharmaceutical companies. Also, Dr. Biederman has a partnership with MEMOTEXT through Partners Healthcare Innovation. Dr. Rohde has received grant or research support from, and served as a consultant to, several companies, including Bial, Novartis, Pfizer, and Shire/Takeda. He has received authorship royalties from Oxford University Press and ArtMed, and travel grants from Shire.

New digital tools are on the horizon to help patients with attention-deficit/hyperactivity disorder (ADHD) manage the condition.

Rostislav_Sedlacek/Thinkstock

Speakers at the World Congress on ADHD – Virtual Event described innovations aimed at improving medication compliance or reducing symptoms through the use of smartphone technology such as apps and text messaging, and video games. Some of these technologies have shown promising results in clinical trials, but the experts called for additional studies to further vet their efficacy.

An explosion in technology

ADHD, the most common neurodevelopmental disorder, has global prevalence rates ranging from 5% to 7%, said Dr. Kirk. Digital technology and digital health “have been heralded as having enormous potential to improve early access and to improve the increasing demand in child support services,” she said.

The world has seen an explosion of digital technology innovation in the last decade, spurred on most recently by the COVID-19 pandemic. New demand exists for tools in educational and health care settings to provide information and support through websites, apps, SMS, video conferencing, and wearable devices, Dr. Kirk said.

Looking at the landscape of ADHD digital therapeutics, “there are probably tens of thousands of apps and other digital products to treat and manage conditions across the spectrum,” said Scott H. Kollins, PhD, MS, a clinical psychologist at Duke Health’s ADHD Clinic in Durham, N.C.

Video game interventions

AKL-T01, a tool that pairs continuous fine motor tasks and perceptual reaction time tasks, went through several rounds of clinical trials to achieve federal approval as a digital therapeutic.

“This not just another video game,” said Dr. Kollins, who helped developed it. The tool’s adaptive algorithms adjust and monitor task difficulty based on performance, using a video game format and rewards to engage users.

Two phase 3 trials provided the basis for the Food and Drug Administration’s approval of AKL-T01, also known as EndeavorRx, in 2020. The first trial, published in The Lancet, randomized 348 children 1:1 to receive either the AKL-T01 treatment or a controlled intervention, which was a word game. Participating children aged 8-12 with a confirmed ADHD diagnosis were asked to play the game for about 25 minutes a day, 5 days a week over 4 weeks. The study excluded children who were taking medicine.

The researchers reported statistically significant improvements in attentional functioning in the AKL-T01 group as rated by test of variables of attention. The trial reported no serious adverse events, although one child in the AKL-T01 group withdrew from the study.

“As kids go through this treatment, it’s challenging and the difficulty levels increase, so it’s not surprising that kids get frustrated with that, or have emotional outbursts,” Dr. Kollins said. Those reactions suggest that the intervention was working, he added.

A follow-up study, published in npj Digital Medicine, broadened the scope. That study included children who had taken medication and extended the study period. Overall, 206 children aged 8-14 (130 on stimulants and 76 on no medication) played the game for 28 days, taking a pause for another 28 days, then reinitiating the treatment.

As in the first trial, AKL-T01 significantly improved ADHD-related impairment, a metric that continued to improve in the second round of treatment. Looking at secondary outcomes, the proportion of children deemed as clinical responders on the Impairment Rating Scale, 68.3% of all of the participants were responders by the end of the study on the ADHD ratings scale, meaning there was a greater than 30% improvement in symptoms. Upward of 50% of participants at the end of the second round of treatment showed substantial improvement in their ADHD ratings scale scores.

“This was really a substantial move ... the first-ever app-based video game approved by the FDA,” noted Dr. Kollins, who is affiliated with the Duke Clinical Research Institute. Some skeptics have called this a marketing ploy or have questioned the integrity of the FDA approval process.

“I would submit and argue that the rigor of the trial speaks for itself,” he said. “But it’s not surprising that there’s skepticism in the clinical community about something like this – a brand new treatment modality.”

In her own research, Dr. Kirk has studied game-based interventions aimed at assessing ADHD and improving cognitive training. In 2018, her team developed a touch screen game–based intervention for early evaluation of attention skills, using six activities. In a visual search task, children were asked to locate red lobsters on a screen that showed a variety of underwater creatures. In another selection attention task, children were asked to scan the screen for a particular target, such as a yellow star, and to indicate whether that target was absent or present on the screen. Other tasks assessed for sustained attention abilities and information processing speed.

She and her colleagues recruited 340 children aged 4-7 years to evaluate whether the tool produced consistent results over time, and compared favorably to existing measures of attention. None of the participants had been diagnosed with ADHD. To assess reliability, a subset of children completed another assessment 2 weeks after the first one. The study showed varying results according to activity. The visual search task had high test-retest reliability and the strongest validity, compared with the other tasks. The sustained attention tasks exhibited the weakest validity.

The next steps are to assess whether this tool is sensitive enough to detect differences between children with or without clinical attention difficulties such as ADHD, Dr. Kirk said.

Apps improve adherence

As some technologies focus on reducing symptoms through games, others seek to improve medication compliance through SMS and smartphone apps.

Studies have shown that medication can decrease incidence of smoking, mood disorders, traumatic brain injuries, car crashes, and educational outcomes. However, risk decreases only if compliance is good, said Joseph Biederman, MD. Right now, “there’s extremely poor adherence to stimulant medications in ADHD” across the world, said Dr. Biederman, chief of clinical and research programs in pediatric psychopharmacology and adult ADHD at Massachusetts General Hospital in Boston.

“This is a problem that’s driven by ADHD itself,” he continued. Prescribers don’t always have the time to educate the patient on medications, deal with misconceptions, or provide support for management of daily activities.

Text reminders may offer a solution. Partnering with a Canadian technology company, MEMOTEXT, Dr. Biederman and colleagues at Massachusetts General Hospital developed an SMS-based disease management intervention for ADHD.

The tool aims to manage work, home life, and social relationships by supporting the timely renewal of medications. It doesn’t just remind people to take their ADHD medication, it reminds them to take any other medication they need, and provides the reasons why it’s important to take these drugs. Through interactive questions, it also assesses the progress and knowledge of patients and families about ADHD.

Testing this app in pediatric settings, Dr. Biederman and colleagues published a study in the Journal of Psychopharmacology showing a dramatic increase in compliance – from 60% to 90%.

In another study, this one published in the Journal of Clinical Psychopharmacology, Dr. Biederman and colleagues found that compliance improved, from 35% to 70% in adults. The SMS program in these settings not only improved adherence, but it also reduced costs of ADHD-associated complications while adding beneficial support and value to patients, families, and prescribers, Dr. Biederman said.

Promising findings about the power of apps to increase ADHD medication adherence led Luis Augusto Rohde, MD, PhD, and colleagues to develop the FOCUS app in 2016, for use in his home country of Brazil. The app objectively monitors symptoms of ADHD and establishes cooperative relationships between the patient, their families, and caregivers, said Dr. Rohde, professor of child and adolescent psychiatry at the Federal University of Rio Grande do Sul’s department of psychiatry, Porto Alegre, Brazil.

Digital tech pros and cons

The accessibility of digital technology to children living in remote areas is one of its biggest assets, Dr. Kirk said.

Digital technologies capture real time data, are easy to use, are suitable for young children with developmental disorders, have few adverse effects, and can be easily updated. However, there are some limitations, she added. Attitudes toward technology, time required to supervise their use, and funding to facilitate the use of such technology can hinder implementation. Given that digital technology is increasingly being used to collect sensitive medical data and assess clinical conditions, it’s crucial for these new technologies to be compliant with HIPAA requirements, Dr. Kirk said.

“We are at the front end of a revolution, and much more of this is coming down the pike,” Dr. Kollins predicted. Developers need to be thoughtful and deliberate in how they design clinical evidence strategies for digital therapeutics for ADHD.

“There’s much work that needs to be done from a clinical, statistical, regulatory, and policy perspective, but this journey illustrates this can be done with ADHD and other mental health conditions.”

Dr. Kirk disclosed working previously for a small technology company in Melbourne that developed medical technologies for children. Dr. Kollins’ work has been supported by numerous U.S. agencies, including the National Institute of Mental Health. He has served as a consultant to numerous pharmaceutical companies tied to ADHD clinical psychopharmacology. Dr. Biederman has provided research support to Genentech, Headspace, Pfizer, Roche Translational & Clinical Research Center, and other pharmaceutical companies. Also, Dr. Biederman has a partnership with MEMOTEXT through Partners Healthcare Innovation. Dr. Rohde has received grant or research support from, and served as a consultant to, several companies, including Bial, Novartis, Pfizer, and Shire/Takeda. He has received authorship royalties from Oxford University Press and ArtMed, and travel grants from Shire.

New digital tools are on the horizon to help patients with attention-deficit/hyperactivity disorder (ADHD) manage the condition.

Rostislav_Sedlacek/Thinkstock

Speakers at the World Congress on ADHD – Virtual Event described innovations aimed at improving medication compliance or reducing symptoms through the use of smartphone technology such as apps and text messaging, and video games. Some of these technologies have shown promising results in clinical trials, but the experts called for additional studies to further vet their efficacy.

An explosion in technology

ADHD, the most common neurodevelopmental disorder, has global prevalence rates ranging from 5% to 7%, said Dr. Kirk. Digital technology and digital health “have been heralded as having enormous potential to improve early access and to improve the increasing demand in child support services,” she said.

The world has seen an explosion of digital technology innovation in the last decade, spurred on most recently by the COVID-19 pandemic. New demand exists for tools in educational and health care settings to provide information and support through websites, apps, SMS, video conferencing, and wearable devices, Dr. Kirk said.

Looking at the landscape of ADHD digital therapeutics, “there are probably tens of thousands of apps and other digital products to treat and manage conditions across the spectrum,” said Scott H. Kollins, PhD, MS, a clinical psychologist at Duke Health’s ADHD Clinic in Durham, N.C.

Video game interventions

AKL-T01, a tool that pairs continuous fine motor tasks and perceptual reaction time tasks, went through several rounds of clinical trials to achieve federal approval as a digital therapeutic.

“This not just another video game,” said Dr. Kollins, who helped developed it. The tool’s adaptive algorithms adjust and monitor task difficulty based on performance, using a video game format and rewards to engage users.

Two phase 3 trials provided the basis for the Food and Drug Administration’s approval of AKL-T01, also known as EndeavorRx, in 2020. The first trial, published in The Lancet, randomized 348 children 1:1 to receive either the AKL-T01 treatment or a controlled intervention, which was a word game. Participating children aged 8-12 with a confirmed ADHD diagnosis were asked to play the game for about 25 minutes a day, 5 days a week over 4 weeks. The study excluded children who were taking medicine.

The researchers reported statistically significant improvements in attentional functioning in the AKL-T01 group as rated by test of variables of attention. The trial reported no serious adverse events, although one child in the AKL-T01 group withdrew from the study.

“As kids go through this treatment, it’s challenging and the difficulty levels increase, so it’s not surprising that kids get frustrated with that, or have emotional outbursts,” Dr. Kollins said. Those reactions suggest that the intervention was working, he added.

A follow-up study, published in npj Digital Medicine, broadened the scope. That study included children who had taken medication and extended the study period. Overall, 206 children aged 8-14 (130 on stimulants and 76 on no medication) played the game for 28 days, taking a pause for another 28 days, then reinitiating the treatment.

As in the first trial, AKL-T01 significantly improved ADHD-related impairment, a metric that continued to improve in the second round of treatment. Looking at secondary outcomes, the proportion of children deemed as clinical responders on the Impairment Rating Scale, 68.3% of all of the participants were responders by the end of the study on the ADHD ratings scale, meaning there was a greater than 30% improvement in symptoms. Upward of 50% of participants at the end of the second round of treatment showed substantial improvement in their ADHD ratings scale scores.

“This was really a substantial move ... the first-ever app-based video game approved by the FDA,” noted Dr. Kollins, who is affiliated with the Duke Clinical Research Institute. Some skeptics have called this a marketing ploy or have questioned the integrity of the FDA approval process.

“I would submit and argue that the rigor of the trial speaks for itself,” he said. “But it’s not surprising that there’s skepticism in the clinical community about something like this – a brand new treatment modality.”

In her own research, Dr. Kirk has studied game-based interventions aimed at assessing ADHD and improving cognitive training. In 2018, her team developed a touch screen game–based intervention for early evaluation of attention skills, using six activities. In a visual search task, children were asked to locate red lobsters on a screen that showed a variety of underwater creatures. In another selection attention task, children were asked to scan the screen for a particular target, such as a yellow star, and to indicate whether that target was absent or present on the screen. Other tasks assessed for sustained attention abilities and information processing speed.

She and her colleagues recruited 340 children aged 4-7 years to evaluate whether the tool produced consistent results over time, and compared favorably to existing measures of attention. None of the participants had been diagnosed with ADHD. To assess reliability, a subset of children completed another assessment 2 weeks after the first one. The study showed varying results according to activity. The visual search task had high test-retest reliability and the strongest validity, compared with the other tasks. The sustained attention tasks exhibited the weakest validity.

The next steps are to assess whether this tool is sensitive enough to detect differences between children with or without clinical attention difficulties such as ADHD, Dr. Kirk said.

Apps improve adherence

As some technologies focus on reducing symptoms through games, others seek to improve medication compliance through SMS and smartphone apps.

Studies have shown that medication can decrease incidence of smoking, mood disorders, traumatic brain injuries, car crashes, and educational outcomes. However, risk decreases only if compliance is good, said Joseph Biederman, MD. Right now, “there’s extremely poor adherence to stimulant medications in ADHD” across the world, said Dr. Biederman, chief of clinical and research programs in pediatric psychopharmacology and adult ADHD at Massachusetts General Hospital in Boston.

“This is a problem that’s driven by ADHD itself,” he continued. Prescribers don’t always have the time to educate the patient on medications, deal with misconceptions, or provide support for management of daily activities.

Text reminders may offer a solution. Partnering with a Canadian technology company, MEMOTEXT, Dr. Biederman and colleagues at Massachusetts General Hospital developed an SMS-based disease management intervention for ADHD.

The tool aims to manage work, home life, and social relationships by supporting the timely renewal of medications. It doesn’t just remind people to take their ADHD medication, it reminds them to take any other medication they need, and provides the reasons why it’s important to take these drugs. Through interactive questions, it also assesses the progress and knowledge of patients and families about ADHD.

Testing this app in pediatric settings, Dr. Biederman and colleagues published a study in the Journal of Psychopharmacology showing a dramatic increase in compliance – from 60% to 90%.

In another study, this one published in the Journal of Clinical Psychopharmacology, Dr. Biederman and colleagues found that compliance improved, from 35% to 70% in adults. The SMS program in these settings not only improved adherence, but it also reduced costs of ADHD-associated complications while adding beneficial support and value to patients, families, and prescribers, Dr. Biederman said.

Promising findings about the power of apps to increase ADHD medication adherence led Luis Augusto Rohde, MD, PhD, and colleagues to develop the FOCUS app in 2016, for use in his home country of Brazil. The app objectively monitors symptoms of ADHD and establishes cooperative relationships between the patient, their families, and caregivers, said Dr. Rohde, professor of child and adolescent psychiatry at the Federal University of Rio Grande do Sul’s department of psychiatry, Porto Alegre, Brazil.

Digital tech pros and cons

The accessibility of digital technology to children living in remote areas is one of its biggest assets, Dr. Kirk said.

Digital technologies capture real time data, are easy to use, are suitable for young children with developmental disorders, have few adverse effects, and can be easily updated. However, there are some limitations, she added. Attitudes toward technology, time required to supervise their use, and funding to facilitate the use of such technology can hinder implementation. Given that digital technology is increasingly being used to collect sensitive medical data and assess clinical conditions, it’s crucial for these new technologies to be compliant with HIPAA requirements, Dr. Kirk said.

“We are at the front end of a revolution, and much more of this is coming down the pike,” Dr. Kollins predicted. Developers need to be thoughtful and deliberate in how they design clinical evidence strategies for digital therapeutics for ADHD.

“There’s much work that needs to be done from a clinical, statistical, regulatory, and policy perspective, but this journey illustrates this can be done with ADHD and other mental health conditions.”

Dr. Kirk disclosed working previously for a small technology company in Melbourne that developed medical technologies for children. Dr. Kollins’ work has been supported by numerous U.S. agencies, including the National Institute of Mental Health. He has served as a consultant to numerous pharmaceutical companies tied to ADHD clinical psychopharmacology. Dr. Biederman has provided research support to Genentech, Headspace, Pfizer, Roche Translational & Clinical Research Center, and other pharmaceutical companies. Also, Dr. Biederman has a partnership with MEMOTEXT through Partners Healthcare Innovation. Dr. Rohde has received grant or research support from, and served as a consultant to, several companies, including Bial, Novartis, Pfizer, and Shire/Takeda. He has received authorship royalties from Oxford University Press and ArtMed, and travel grants from Shire.