"Does Psychiatry Need Science?"

"A group of seventeen prominent doctors;biological psychiatrists, experts in diagnostics, subspecialists in the field of depression, and even a historian; petitioned the D.S.M.-5 mood-disorders committee to add a diagnosis they named melancholia... melancholia lost its place in psychiatric nosology in 1980, when all forms of depression were consolidated under a single diagnostic label...

The group argued that this was a grievous scientific error and cited evidence that melancholia was qualitatively different from other forms of depression. Some of the evidence was derived from the same kind of clinical observation that is the backbone of the D.S.M. For instance, people who showed the characteristic clinical symptoms—an unshakeable despondency and sense of guilt that arises from nowhere, responds to nothing, and dissipates for no apparent reason—also displayed some distinctive physical signs: hand-wringing, for instance, and psychomotor retardation, an easily perceived slowing down of movement, thought, and speech. But some of the group’s proof was of precisely the kind that psychiatrists had been looking for since the nineteenth century. Thirty years of replicated studies had shown that patients with those signs and symptoms had a sleep architecture and cortisone metabolism that was distinct from that of other people, both normal and depressed. A night in a sleep lab could detect the reduced deep sleep and increased REM time characteristic of melancholics, and a dexamethasone suppression test (D.S.T.) could determine whether or not a patient’s stress hormones were in overdrive, as is generally the case among melancholic patients. And melancholia responded better than other kinds of depression to two treatments: tricyclic antidepressants (the first generation of the drugs) and electroconvulsive therapy (E.C.T., better known as shock therapy)...

“I believe you and your colleagues are fundamentally correct,” committee member William Coryell wrote to the melancholia advocates, by way of explaining his panel’s inaction. But “the inclusion of a biological measure 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.”"

http://www.newyorker.com/tech/elements/does-psychiatry-need-science

That's really fascinating - it's making me wonder about how it is that we detect disorders, and how it is that we perceive them. Some are obvious and distinct; others have no clear boundaries; and there are probably a lot that we are missing. And then it gets into the definition of disorder: if it is missable, and doesn't seem to impact daily life or can be treated just the same as another disorder, is it distinct? And is there any such thing as living an "un-disordered" life?