Challenging the DSM-5
May saw the long anticipated publication of the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, the “bible” used by medical practitioners, insurance carriers, legislators and even courts when they need info on mental illness.
Along with the publication came the criticisms, but this time around, some well-respected scientists – even some in psychiatry – joined the chorus.
Behind the Scenes
Because it is used to define categories and classes of mental illnesses, the DSM-5, in a sense, creates the subject it talks about. If it says that hoarding disorder (real example) is a real mental illness instead of a symptom of obsessive compulsive disorder, then it is. It also lists the diagnostic criteria needed to make the diagnosis. This is not to say that mental illness is created out of whole cloth, mental disorders certainly exist. But how behaviors are categorized, divided up and described is the “made up” part.
An interview in the Atlantic explains how the DSM-5 was authored:
The American Psychiatric Association owns the DSM. They aren't only responsible for it: they own it, sell it, and license it. The DSM is created by a group of committees. It's a bureaucratic process. In place of scientific findings, the DSM uses expert consensus to determine what mental disorders exist and how you can recognize them. Disorders come into the book the same way a law becomes part of the book of statutes. People suggest it, discuss it, and vote on it.
That’s not to say these aren’t experts in their fields – they are. But there’s a fundamental problem with basing diagnosis on behavior.
Just before the release of the latest DSM, Dr. Thomas Insel announced a new initiative to change the way mental illness is defined and treated. Insel is no lightweight, he’s the current head of the National Institutes of Mental Health. As director of NIMH, his criticisms were heeded.
According to a press release from the NIMH, the diagnostic criteria should reflect current and future understandings about how the mind works in a more scientific manner. An analogy sometimes used is with the diagnosis of pneumonia.
A patient may present with the same set of symptoms for both pneumonia and lung cancer. Using behavior alone, a physician would have difficulty distinguishing the two diseases. It’s only by looking at the physiology (using X-ray, sputum samples and maybe a biopsy) that the proper diagnosis can be determined. And the proper diagnosis will then drive the correct treatment.
The difference between how mental illness is treated and how other conditions are treated is subtle, but comes down to whether it is enough to list behaviors and self reporting from patients to get a useful diagnosis or whether we should have clinical and laboratory findings to back this up. When similar behaviors can stem from different causes, it only makes sense to differentiate them based on measurable differences.
Along with this concern for getting more science into the mix, there is a re-hashing of some of the historical ways descriptive psychiatry has gone wrong. One is the interesting behavior (and possible diagnosis) of drapetomania. The behavior labeled as drapetomania was well known at the time of the proposed diagnosis (1851). Drapetomania was the unnatural desire for a slave to escape their proper position and status. Another, more recent example of a behavior mislabeled as a mental illness is the diagnosis of homosexuality. It was listed as recently as 1972 as a type of sociopathic abnormality that stemmed from a fear of the opposite sex.
High Specificity, Low Validity
As a communication tool, the DSM offers a very good way for one mental health professional to understand another. They can use the labels to specify, to a high degree, what they mean by major vs. minor depression. This is very useful and the DSM serves as a kind of dictionary in this way. But what is lacking, according to Dr. Insel and others, is validity. While we can clearly label someone as depressed, or addicted, or any of a hundred diagnoses, we can’t really say why they fit that pattern.
In other words, two patients with the same diagnosis could have very different etiologies. I might drink too much because I’m depressed, you might drink to stave off anxiety when trying to meet people, and a third might do it because of impulse control issues – but we’d all be labeled as alcohol abusers. The label doesn’t help when it comes to treatment.
That’s what happened above, with hoarding disorder. Enough evidence mounted that it wasn’t a type of obsessive compulsive disorder (part of the evidence being that OCD treatments didn’t help hoarders much) and needed its own category.
The discussions will continue, and psychiatrists are not averse to getting clear diagnostic criteria from neuroanatomists and neurobiologists. For now however, most conditions will continue to rely on the expert opinions and committee consensus in the DSM-5.
Homosexuality was deleted from the DSM by a referendum. A straight up vote: yes or no. It's not always that explicit, and the votes are not public. In the case of the DSM-5, committee members were forbidden to talk about it, so we'll never really know what the deliberations were. They all signed non-disclosure agreements.