"But psychiatrists still cannot meet this demand. A detailed understanding of the brain, with its hundred billion neurons and trillions of synapses, remains elusive, leaving psychiatry dependent on outward manifestations for its taxonomy of mental illnesses."
Psychiatrists develop diagnoses by observations of patients and by assessing self-reported symptoms of patients. They use the same approach in determining the efficacy of treatments.
The D.S.M. provides a cookbook approach whereby symptoms can be catalogued and compared with possible mental illnesses. Of course, a set of symptoms need not be uniquely associated with a specific illness so it is of limited precision. Its main strength is in its simplicity and its authority. It can be interpreted and used to make a diagnosis by anyone capable of reading: parents, teachers, school nurses, psychologists, and medical doctors with no training in psychiatry. Because it is produced by a medical association it is assumed to have the same authority as a similar document produced by any science-based medical profession.
Did psychiatry still feel uncomfortable with its lack of a physical basis for their actions, or had they become comfortable with the simplicity it provided? Greenberg became suspicious when he observed what transpired when a group of experts advocated adding the diagnosis of the condition known as melancholia.
"The proposal was not so much an innovation as a retrieval of an old idea. Melancholia is one of the most venerable of psychiatric disorders, noted by doctors at least as far back as Hippocrates, who attributed its characteristic dejection and unresponsiveness to external events to an excess of black bile. But melancholia lost its place in psychiatric nosology [disease classification] in 1980, when all forms of depression were consolidated under a single diagnostic label—‘major depressive disorder’—of which melancholia was only a variant. It was the D.S.M. equivalent of calling Pluto just another ice dwarf in the Kuiper Belt."
The group argued that melancholia was, in fact, a unique disease. While it had observable symptoms that might be confused with manifestations of other forms of depression:
The petitioners could provide evidence that melancholia could be detected by medical tests while other forms of depression could not.
One might have expected psychiatry to be thrilled with this request.
But one would have been wrong.
Incredibly, it was the scientific basis for the diagnosis and treatment that rendered it unacceptable to the D.S.M. committee.
As Greenberg so aptly summarized:
Science marches on, but psychiatry has found a sweet spot where it is comfortable and willing to live for the foreseeable future with diagnosis and treatment by committee revelation.