While the Diagnostic and Statistical Manual of Mental Disorders, or D.S.M., is the best tool now available for clinicians treating patients and should not be tossed out, he said, it does not reflect the complexity of many disorders, and its way of categorizing mental illnesses should not guide research.
“As long as the research community takes the D.S.M. to be a bible, we’ll never make progress,” Dr. Insel said, adding, “People think that everything has to match D.S.M. criteria, but you know what? Biology never read that book.”
Insel describes the problem of all psychiatric diagnoses:
“Unlike our definitions of ischemic heart disease, lymphoma, or AIDS, the DSM diagnoses are based on a consensus about clusters of clinical symptoms, not any objective laboratory measure. In the rest of medicine, this would be equivalent to creating diagnostic systems based on the nature of chest pain or the quality of fever.”
It's interesting, a lot of people will come on here and baldly assert, "sociopaths don't do this" or "that's not what borderline personality disorder is." And that's fine. I understand the flaws and ambiguities in my own working definitions of psychiatric disorders. And I also understand that despite the fuzziness of the definitions, it's still useful to acknowledge that there seems to be commonalities between certain categories of people that deserve further explanation. But I do believe that people have used the DSM unquestioningly for far too long, taking it to the level of being DSM apologists rather than accepting new information with an open-mind, and I'm glad that there is now more pressure to provide actual science behind the various assertions.
For more on the DSM-5's explicit rejection in one instance of actual scientific proof of a separate psychiatric disorder, see this New Yorker article's discussion of melancholia:
[T]he inclusion of a biological measure [for melancholia] would be very hard to sell to the mood group." Coryell explained that the problem wasn’t the test’s reliability, which he thought was better than anything else in psychiatry. Rather, it was that the D.S.T. would be "the only biological test for any diagnosis being considered." A single disorder that met the scientific demands of the day, in other words, would only make the failure to meet them in the rest of the D.S.M. that much more glaring.
This notion—that the apparent mental condition is all that can matter—underlies not only the depression diagnosis but all of the D.S.M.’s categories. It may have been conceived as a stopgap, a way to bide time until the brain’s role in psychological suffering has been elucidated, but in the meantime, expert consensus about appearances has become the cornerstone of the profession, one that psychiatrists are reluctant to yank out, lest the entire edifice collapse.
"What can be asserted without evidence can be dismissed without evidence."