Science

'There Is No Definition of a Mental Disorder'

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Gary Greenberg's recent Wired article about the anxiously anticipated and repeatedly delayed fifth edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DMS-5) begins with a revealing admission. "There is no definition of a mental disorder," Allen Frances tells him. "It's bullshit. I mean, you just can't define it….These concepts are virtually impossible to define precisely with bright lines at the boundaries." Frances should know. As the lead editor of the current DSM, Greenberg writes, he is literally "the guy who wrote the book on mental illness."

But the fact that there is no precise, workable, meaningful definition of mental disorders will not stop the APA from trying once again to catalog them. As Greenberg observes, too much is at stake to stop now, including psychiatry's legitimacy, drug companies' profits, and the ability of mental health professionals to get paid for their work by picking a code out of the APA's bible. Frances himself is not suggesting that the APA stop the "bullshit"—only that it proceed a little more carefully. He regrets that DSM-IV, the revision he oversaw, preciptated a 40-fold explosion in diagnoses of bipolar disorder in children, who ended up taking powerful psychotropic drugs with uncertain long-term effects "even if they had never had a manic episode and were too young to have shown the pattern of mood change associated with the disease." He worries that something similar might happen if DSM-5 includes a "pre-psychotic" disorder that psychiatrists will be keen to treat preventively with drugs. In a 2009 Psychiatric Times essay, Frances warned that an emphasis on early intervention would encourage the "wholesale imperial medicalization of normality," producing "a bonanza for the pharmaceutical industry" while imposing on patients the "high price [of] adverse effects, dollars, and stigma." Robert Spitzer, the lead editor of DSM-III, seems to have similar concerns about reckless definitions, complaining that the revision process has been excessively secretive.

For his part, Greenberg, a psychotherapist and the author of Manufacturing Depression: The Secret History of a Modern Disease, walks to the precipice of calling psychiatry a pseudoscience before turning back:

The authority of any doctor depends on their ability to name a patient's suffering. For patients to accept a diagnosis, they must believe that doctors know—in the same way that physicists know about gravity or biologists about mitosis—that their disease exists and that they have it. But this kind of certainty has eluded psychiatry, and every fight over nomenclature threatens to undermine the legitimacy of the profession by revealing its dirty secret: that for all their confident pronouncements, psychiatrists can't rigorously differentiate illness from everyday suffering. This is why, as one psychiatrist wrote after the APA voted homosexuality out of the DSM, "there is a terrible sense of shame among psychiatrists, always wanting to show that our diagnoses are as good as the scientific ones used in real medicine."

Since 1980, when the DSM-III was published, psychiatrists have tried to solve this problem by using what is called descriptive diagnosis: a checklist approach, whereby illnesses are defined wholly by the symptoms patients present. The main virtue of descriptive psychiatry is that it doesn't rely on unprovable notions about the nature and causes of mental illness, as the Freudian theories behind all those "neuroses" had done. Two doctors who observe a patient carefully and consult the DSM's criteria lists usually won't disagree on the diagnosis—something that was embarrassingly common before 1980. But descriptive psychiatry also has a major problem: Its diagnoses are nothing more than groupings of symptoms. If, during a two-week period, you have five of the nine symptoms of depression listed in the DSM, then you have "major depression," no matter your circumstances or your own perception of your troubles. "No one should be proud that we have a descriptive system," Frances tells me. "The fact that we do only reveals our limitations." Instead of curing the profession's own malady, descriptive psychiatry has just covered it up.

The descriptive approach says nothing about etiology, and Greenberg suggests it is not necessarily helpful in determining treatment. He describes a conversation with a former APA president who had recently diagnosed a patient with "obsessive compulsive disorder" after seeing her for a couple of months. He did so purely for insurance purposes (something Greenberg himself admits doing in Manufacturing Depression). The psychiatrist tells Greenberg that the label did not change the way he treated the patient, but "I got paid."

Yet Greenberg is not hopeful about the National Institute of Mental Health's efforts to identify the brain abnormalities underlying "mental disorders," thereby transforming psychiatry into "clinical neuroscience" (which is what Thomas Szasz, a much more radical critic of psychiatry, says the field would be if it were a legitimate branch of medicine). In the end, Greenberg concludes that the "provisional" judgments embodied in the DSM are the best that can be accomplished for the foreseeable future. He notes that more rigorous branches of medicine also have evolving disease definitions. For example, "diabetes is defined by a blood-glucose threshold, one that has changed over time."

True enough, but the indicator for diabetes can be measured objectively with a biological test. While the causes of diabetes, whether Type 1 or Type 2, are not completely understood, there are clear risk factors and plausible theories that can be investigated further. The disease has a predictable course, and it can be reliably treated. How many of the "mental disorders" listed in the DSM satisfy these criteria? The "imperial medicalization of normality" that worries Frances (and Greenberg) is possible precisely because DSM descriptions are unmoored from the sort of evidence on which standard medical diagnoses are based. And while psychiatrists and other mental health practitioners concede among themselves the "provisional" nature of the DSM, that is certainly not the impression they give to the people they label.

I considered some of these issues in a 2005 review of Szasz Under Fire: The Psychiatric Abolitionist Faces His Critics.