DSM-5 will be the last
By Edward Shorter
In assessing DSM-5, the fog of battle has covered the field. To go by media coverage, everything is wrong with the new DSM, from the way it classifies children with autism to its unremitting expansion of psychiatry into the reach of “normal.” What aspects should we really be concerned about?
Think of a bowl of spaghetti. There are the central swirls of spaghetti in the middle of the bowl and the strands of spaghetti hanging over the side. Most of the controversy has been about the strands dangling down, how we classify marginal disorders of various kinds. It’s not that people with these disorders, such as the hyperactive and the autistic, aren’t important, but they aren’t the meat and drink of psychiatry.
The problem that the DSM-5 doesn’t address lies at the center of the bowl. It concerns psychiatry’s main diagnoses, not its marginal outliers, and those main diagnoses are major depression, bipolar disorder, and schizophrenia. The new edition hasn’t really touched any of them; the way they were defined and classified, and the way they continue to be recognized, ignores major differences within each diagnosis.
Keep in mind how easy it has been to get funny-sounding new diagnoses into psychiatry. Some, such as bipolar disorder, come in as a result of fad. A German psychiatrist named Karl Leonhard created bipolar disorder in 1957 when he said that there are two kinds of depression, unipolar depression (no mania) and the depression that alternates with mania (later called, in DSM-3 in 1980, bipolar disorder). Leonhard’s European and American disciples — a small but influential band — saw to it that separating depressions by “polarity” was widely accepted. Yet there was no new science here; it was the whim of one man.
Some of the diagnoses at the heart of the bowl came in by fiat. Robert Spitzer, the architect of DSM-3, simply decided in 1980 to collapse psychiatry’s various depressions — which had been as diverse as chalk and cheese — into a single disorder: major depression. There were howls of protest, but, hey, the thing was already in print. Set in stone. Even though it makes no scientific sense to classify depressions on the basis of polarity, that’s what we have ended up doing.
Serious depression — or melancholia — remains serious depression whether an episode of mania complicates it or not. Sooner or later, many patients with serious depression will experience some manic features, without that changing their basic diagnosis.
Related to schizophrenia, psychosis (loss of contact with reality via hallucinations or delusions) certainly exists. And there are many forms of it: some come out of the blue, others begin insidiously and seem to grow out of the patient’s personality; some involve loss of brain tissue, others don’t; some end very badly, others stabilize at the ability to lead a more or less normal life: you may not become a neurosurgeon, but you get married, have kids, keep a job, the whole ball of wax. These are different diseases.
Yet we now give all these forms of psychosis a single diagnosis: schizophrenia. That’s without a plural “s.” If you’ve got chronic psychosis you’ll be called schizophrenic, even though you may not have any symptoms in common with others who have that diagnosis. You may have quite different family (genetic) backgrounds; you may not have a common response to treatment; and you may not have a common course and outcome. Those are all the ways we delineate separate diseases and “schizophrenia” demonstrates none of those hallmarks. It’s an artifact that Emil Kraepelin, the great German disease classifier, inserted into the literature in the 1890s, calling it dementia praecox. So powerful was his concept — that all the different “subtypes” of schizophrenia went remorselessly downhill — that the term has survived the relentless scientific plucking that all other diagnoses in medicine continually experience.
But conceptual power is not the same thing as verification. There is no marker telling us that everybody with “schizophrenia” has the same disease. (There are, by the way, such markers for some other major diseases; I don’t have space to go into it here, but google “dexamethasone suppression test”.)
So, are there problems with DSM-5? Yes, but they aren’t the problems most critics pick at. Criticisms of DSM-5 seem to be rising in a crescendo, as though a gaggle of high-school teachers were called to assess the work of a very naughty schoolboy. The drafters of the current edition were mightily concerned with maintaining stability; they didn’t want to hack great changes into previous editions. So there is not a chance in the world they would have looked critically at these central problems.
But out there in the real world, there are growing numbers of nosological rebels, or skeptics about the DSM version of disease classification. They have mainly stayed off the airwaves up to now. But you can feel the dubiety rising. There probably will not be a DSM-6.
Edward Shorter is Jason A. Hannah Professor in the History of Medicine and Professor of Psychiatry in the Faculty of Medicine, University of Toronto. He is an internationally-recognized historian of psychiatry and the author of numerous books, including How Everyone Became Depressed: The Rise and Fall of the Nervous Breakdown, A Historical Dictionary of Psychiatry and Before Prozac: The Troubled History of Mood Disorders in Psychiatry. Read his previous blog posts.
The OUPblog is running a series of articles on the DSM-5 in anticipation of its launch on 18 May 2013. Stay tuned for views from Daniel and Jason Freeman, Donald W. Black, Michael A. Taylor, and Joel Paris.
Image credit: By Otis Historical Archives National Museum of Health and Medicine (originally posted to Flickr as Reeve37258). Creative commons license via Wikimedia Commons.