The Director of the National Institute of Mental Health (NIMH) recently announced that the institute will no longer rely on the Diagnostic and Statistical Manual of Mental Disorders (DSM) in studying and researching mental disorders. Four versions of the DSM have been published by the American Psychiatric Association (APA) since 1952, and a new version–the DSM-5–is expected to come out this month. Practitioners rely on the DSM to diagnose illnesses. According to NIMH Director Thomas Insel, however, “While DSM has been described as a “Bible” for the field, it is, at best, a dictionary, creating a set of labels and defining each . . . Patients with mental disorders deserve better.” Instead, the NIMH will pursue the Research Domain Criteria (RDoC) project, a decade-long undertaking that will gather data to develop a new classification system.
NIMH Criticism and the RDoC
Insel concedes that the DSM has served to provide practitioners with terminology to use in diagnosing patients. However, he faults the manual for its lack of validity, noting that it bases diagnoses on symptoms-only, rather than including objecting laboratory measures in the process. Insel describes this as the equivalent of basing a diagnosis on the “nature of chest pain or the quality of fever.” It has been particularly difficult to meaningfully apply the results of clinical studies, since the results might not be clearly applicable to current diagnostic categories. For example, some risk genes for psychotic disorders are associated with both schizophrenia and bipolar disorder; a particular prefrontal region of the brain has been implicated in both depression and post-traumatic stress disorder (PTSD). The RDoC hopes to collect enough information to allow scientists to begin classifying mental disorders based on physical criteria, rather than lists of symptoms alone. It will incorporate various forms of measurement, including imaging and physiological activity, which will run the range from normal to abnormal. The NIMH hopes that this type of precision medicine will eventually lead to a way to subdivide syndromes into groups that are responsive to particular medicines and treatments–although a medicine or treatment may not be effective for everyone, it may be very effective for a particular group of people.
Other critics of the DSM have been more outspoken, arguing that the manual is expanding its definitions of mental illness to include relatively normal behaviors. The DSM-5, for example, is expected to include a diagnosis of Disruptive Mood Dysregulation Disorder, which includes children ages 6-18 who have temper tantrums “grossly out of proportion in intensity or duration to the situation.” Critics contend that this will lead to overmedication of children who do not require that type of intervention. The APA, however, maintains that the diagnosis is limited to children already under the care of mental health practitioners and will discourage practitioners from incorrectly diagnosing certain patients with bipolar disorder. Dr. Bernard Carroll, a former chairman of Duke University’s psychiatry department, is appalled at the 40-fold increase in diagnoses of bipolar disorder that have occurred over the past two decades. “You’ve got all these young kids running around with this diagnosis, yet many of them have never, ever had a manic episode, which is the hallmark of bipolar disorder.” According to Carroll, misdiagnosis can lead to unnecessary medications, the side effects of which can include permanent disfigurement. One psychotherapist, Gary Greenberg, claims that improperly diagnosing someone with a mental illness is worse than missing a diagnosis, because the false diagnosis can change a person’s identity. Greenberg also reminds readers that homosexuality was listed as a disease until 1973.
In Defense of DSM-5
Despite recent criticisms, the DSM-V retains a number of supporters. Indeed, despite the negative press that the manual has been receiving lately, it is still relied on by the FDA for drug trial requirements and by insurance companies for deciding whether or not to cover certain types of treatment. It is also the basis for many awards of research grants. Practitioners acknowledge problems with the manual, but it remains the most comprehensive in the field. Dr. David Kupfer, chair of the DSM-5 Task Force, notes, “the current manual’s shortcomings, particularly in the area of childhood disorders, compel us to move forward now, with changes supported by the most credible research available and the practical experiences provided by our field trials. We then need to maintain vigilance, understanding that improvement will be an ongoing process. Science will advance and we will learn more about the intersection of brain, genes, environment, and behavior. DSM must reflect that knowledge. Our patients will be better off for it.”