Mind Over Manual
EARLIER this summer, the American Psychiatric Association announced that a 27-member panel will update its official diagnostic handbook, the Diagnostic and Statistical Manual of Mental Disorders. The fifth edition, which is scheduled to come out in 2012, is likely to add new mental illnesses and refine some existing ones.
High on the agenda will be the controversial diagnosis of childhood bipolar disorder. Recent data show that office visits by children and adolescents treated for the condition jumped 40-fold from 1994 to 2003. We still don’t know how much of this increase represents long-overdue care of mentally ill youth and how much comes from facile labeling of youngsters who are merely irritable and moody.
Part of the confusion stems from the lack of a discrete definition of juvenile bipolar illness in the diagnostic manual. But there is a deeper problem: despite the great progress being made in neuroscience, we still don’t have a clear picture of the brain mechanisms underlying bipolar illness — or most other mental illnesses.
For perspective, we must return to 1980, when the revolutionary third edition of the handbook, the D.S.M. III, was published. In a radical break from earlier editions, which had been based largely on psychoanalytic principles of unconscious conflict and stunted sexual development, the D.S.M. III categorized illnesses based on symptoms. A patient was said to have a condition if he or she had a certain number of the classic symptoms for a certain period of time. This approach promoted “inter-rater reliability” — the odds that two examiners would agree on what diagnosis to assign a patient.
Yet the manual remained silent on what caused the symptoms. The diagnosis of, say, schizophrenia did not reflect a known cause in the way syphilis is known to be an infection with a spirochete bacterium. The writers of the D.S.M. III were confident that science would one day fill this vacuum, yet three decades later psychiatry still lacks a firm grasp of the causal underpinnings of mental illness.
One manifestation of our limited knowledge is that many patients meet several diagnostic definitions at once. Roughly half of adults with clinical depression, for example, also have symptoms that fit the definition of an anxiety disorder. Do these patients actually suffer more than one illness, or do they just appear to?
Conversely, very diverse patients often qualify for the same diagnosis. “You can have three patients with schizophrenia, but all that really means is that their symptoms fit a particular pattern,” says Dr. Michael First, a psychiatrist who was the editor of the current handbook, the D.S.M. IV. “They may not have the same pathophysiology and, as a result, they may not require the same treatment.”
Indeed, the link between diagnosis and treatment is relatively weak. Antidepressants like Prozac help treat not only depression but also panic disorder, obsessive-compulsive disorder, bulimia and social phobia. This explains why clinicians often treat by symptom rather than diagnosis. Paranoia, for example, is treated with an antipsychotic drug whether it occurs in the context of schizophrenia, bipolar illness or methamphetamine use.
Why aren’t we closer to understanding the relationship between manifest illness and its underlying causes? One obstacle is the staggering complexity of the brain. Another may be what Dr. First calls the “unfortunate rigidity” that all-or-nothing diagnostic checklists and sharply bounded categories impose. In order for the condition of a patient to meet the definition of clinical depression, for example, he or she must have five out of nine symptoms. But does a patient with only four symptoms have a different disorder, or no disorder at all?
One way to improve the classification of mental illnesses would be to define certain pathologies along a continuum so that patients who are truly ill won’t fall short of qualifying for a diagnosis. Take major depression. The symptoms could be weighted so that suicidal preoccupation or immobilization, the most extreme and debilitating aspects, would get high scores, while loss of energy and interest for a short periods would get lower scores. Thus, a patient with few, but severe, symptoms would not be excluded.
A more nuanced approach could also make a real difference for population surveys of mental illness and clinical trials, both of which tend to rely on rigid symptom checklists.
An updated manual, however, is unlikely to transform treatment substantially — after all, revising diagnoses is still just another way to describe mental conditions we don’t fully understand. But these refinements may well stimulate valuable new inquiry, enabling swifter progress in understanding the mechanisms of disease, better deployment of treatments we have and more efficient discovery of new ones.
Sally Satel, a psychiatrist and resident scholar at the American Enterprise Institute, is a co-author of “One Nation Under Therapy.”
The Brain, the Mind and Mental Illness
To the Editor:
Sally Satel (“Mind Over Manual,” Op-Ed, Sept. 13) suggests that the diagnostic confusion within psychiatry is due to a lack of “a clear picture of the brain mechanisms underlying ... mental illnesses.” She says psychiatry “lacks a firm grasp of the causal underpinnings of mental illness,” suggesting the “staggering complexity of the brain” as one reason.
Her article suffers in its being biased by the current zeitgeist that overemphasizes brain-based mechanisms as causes. While this may, in fact, have explanatory power for some conditions, it is more likely that causal explanations will often include frames of reference that are psychological (including psychodynamic) as well as biological.
Ken Kendler, a prominent psychiatric researcher, has pointed out that straightforward causal mechanisms (like the spirochete bacterium causing syphilis) are unlikely to apply to any of the major mental disorders because of their complex nature.
If we only look at “brain” causes and neglect the mind and the social world our patients live in, we lose a balanced perspective that our patients deserve and need.
Larry S. Sandberg, M.D.
New York, Sept. 14, 2007
The writer is clinical associate professor of psychiatry at Weill Cornell Medical College and co-author of “Psychotherapy and Medication: The Challenge of Integration.”
To the Editor:
Sally Satel’s excellent review asks: “Why aren’t we closer to understanding the relationship between manifest illness and its underlying causes? One obstacle is the staggering complexity of the brain.”
The recent genomic decoding of a “full, or diploid, genome” as revealed by Dr. Craig Venter (Science Times, Sept. 4) could lead the way. Genomic discoveries will undoubtedly produce a better understanding of mental disorders and their treatment.
DSM-V is not scheduled to come out until 2012. Enhanced communication between clinical and research doctors would be helpful. Financing is essential for such promising advances to treat human suffering from mental disorders. The public needs to be made aware of the discrepancy between the funds for research available for mental disorders as compared with medical illness.
Barbara E. O’Connell, M.D.
Rye, N.Y., Sept. 13, 2007
The writer is a distinguished life fellow of the American Psychiatric Association and a past president of the Westchester Psychiatric Association.
To the Editor:
The American Psychiatric Association clearly identifies the limitations of the DSM-IV in the text’s introduction as follows:
“The specific diagnostic criteria included in DSM-IV are meant to serve as guidelines to be informed by clinical judgment and are not meant to be used in a cookbook fashion. For example, the exercise of clinical judgment may justify giving a certain diagnosis to an individual even though the clinical presentation falls just short of meeting the full criteria for the diagnosis as long as the symptoms that are present are persistent and severe.”
Thank goodness that clinical judgment trumps cookbook guidelines. Maybe this disclaimer needs to be in bigger font in the coming fifth edition.
Todd Rosen, M.D.
Bloomfield Hills, Mich., Sept. 13, 2007