SAN FRANCISCO – Changes to the psychosis section of the long-awaited fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) are hardly dramatic, but they are still likely to advance the field and make the classification system more clinically relevant and easier to use, according to the authors.
Representatives of the 12-member Work Group on Psychotic Disorders detailed some of the revised elements of this section of the new manual, which was released with the start of the annual meeting of the American Psychiatric Association.
Key changes are outlined
Dr. Rajiv Tandon
"When we were approaching the DSM-5, we thought we learned so much in the last 20 years about the nature of all these psychotic disorders – such incredible advances in imaging and genetics and all these different areas of neurobiology – that, somehow, we were going to revolutionize diagnosis with an etiopathophysiological classification, if you will," commented Dr. Rajiv Tandon of the University of Florida, Gainesville. "And relatively early in the process, we recognized that that was impossible to accomplish, because although we learned a lot, we didn’t know enough yet to be able to do that."
Still, the new edition differs from its predecessor, the DSM-IV, released nearly a decade ago, in a variety of key respects, he said.
For example, gone are the subtypes of schizophrenia, along with shared psychotic disorder. Newly added is catatonia not elsewhere classified, referring to a fully defined catatonic syndrome in the absence of an identifiable medical disorder.
The DSM-5 also sees the debut of assessment of the dimensions of psychosis, which captures the presence and severity of various symptoms. In addition, the criteria for diagnosing schizoaffective disorder have been modified, and catatonia is now treated more uniformly across the manual.
"What we have come up with regard to psychotic disorders are iterative changes, modest improvements, improved clinical utility, simplicity – we have actually reduced the number of disorders in our section by about 20%," Dr. Tandon said. "Very importantly, in addition to improved clinical utility and incorporating the new information we have learned to the extent possible, the DSM-5 look at psychotic disorders provides a much better platform to a future etiopathophysiological classification."
DSM, RDoC called complementary
Dr. Dolores Malaspina
The DSM-5’s new dimensional approach to assessing psychotic disorders will not only help advance the study of these disorders, but will also help to track their course in patients over time and ensure appropriate treatment, said Dr. Dolores Malaspina of the NYU Langone Medical Center in New York.
Clinicians will rate the presence and severity of eight symptoms – hallucinations, delusions, disorganized speech, psychomotor behavior, negative symptoms, impaired cognition, depression, and mania – on a scale from 0 to 4.
In particular, this approach will promote patient-centered care, she maintained. "We want our treatments to be person specific. For a treatment to be person specific, it’s not simply based on a diagnosis."
Dr. Malaspina further noted that dimensional assessment addresses some of the National Institute of Mental Health’s reservations about the DSM classification system.
"The NIMH has come to see the categories of the DSM as getting in the way of progress forward," she explained. The NIMH, therefore, developed its own classification system, called Research Domain Criteria (RDoC).
"Their goal is to do studies where symptoms have been assessed along a continuum. This approach is not antagonistic to the DSM – there is actually no dueling that will take place in the Moscone Center," she quipped, referring to the location of the APA meeting in San Francisco. "There actually is a great amount of agreement. The future of psychiatric assessment should see that the DSM-5 and the RDoC are complementary, not competing frameworks."
Cognitive impairment left out
Patients with schizophrenia commonly have impaired cognition, so clinicians might be surprised to find that this feature is still not listed as a core feature in the DSM-5, noted Dr. Raquel E. Gur of the University of Pennsylvania, Philadelphia.
"To meet the core features of hallucinations, delusions, and disorganized thinking, you must have impaired cognition, otherwise you will not perceive events around you differently than other people. There is something that happens in the brains of these people that make them distort reality, and those things are measurable," she commented.
Moreover, cognitive status is important when assessing the ability of patients to engage in treatment and when it comes to setting realistic goals of care.
To be sure, the DSM-5 describes assessment of cognitive status as vital to the differential diagnosis when distinguishing entities on the schizophrenia spectrum from other psychotic disorders.