The DSM-IV is the standard for diagnosing psychiatric disorders. It lists the disorders and what symptoms a patient needs to have to 'meet criteria' for that disorder. It reads a little like a Chinese Menu-- if you have one/two/however many symptoms from column A and a certain number of symptoms from column B...you get the idea. What's interesting is that it's the Diagnostic and Statistical Manual of Mental Disorders, but there's nothing Statistical about it. The criteria are decided by committees, not by experiments or long-term studies that follow prognosis, not by response to medications, not by the presence or absence of a gene or chemical or abnormal brain structure. Yes, we talk about the genetic predisposition to illnesses and chemical imbalances, but they're all assumed (sometimes by rather strong evidence). We treat brain disorders, but we don't know the precise biological etiology of any psychiatric disorder. (Okay, Huntington's Disease, but that's considered a neurologic disorder that has associated psychiatric manifestations).
So the committees that define the disorders (not statistically) are faced with all kinds of issues, particularly around the inclusion or not of many the things we talk about here at Shrink Rap. Is criminal behavior a psychiatric disorder? Binge eating? Homosexuality (-- homosexuality was removed as a psychiatric disorder some time ago).
So what's a disorder (there are apparently 283 ways to be mentally disordered) and how do we arrive at these decisions? There's the politics of it all, there's insurance reimbursement implications, and I imagine the pharmaceutical companies care how the cards fall. The committee members have to limit their income from pharmaceutical companies during the process of DSM work. To further the controversies of it all, the process has been questioned in terms of how transparent it is and who has access to what goes on in the meetings.
In yesterday's New York Times, Benedict Carey address some of these issues in "Psychiatrists Revise the Book of Human Troubles:"
The scientists updating the manual have been meeting in small groups focusing on categories like mood disorders and substance abuse — poring over the latest scientific studies to clarify what qualifies as a disorder and what might distinguish one disorder from another. They have much more work to do, members say, before providing recommendations to a 28-member panel that will gather in closed meetings to make the final editorial changes.
Experts say that some of the most crucial debates are likely to include gender identity, diagnoses of illness involving children, and addictions like shopping and eating.“Many of these are going to involve huge fights, I expect,” said Dr. Michael First, a professor of psychiatry at Columbia who edited the fourth edition of the manual but is not involved in the fifth.