The DSM again

The Diagnostic and Statistical Manual of the American Psychiatric Association (DSM-V) is in the news. The press has not been favorable, nor have two new books concerning it. Here are some links

l. A review of a book on it from today’s Nature (2 May ’13)–http://www.nature.com/nature/journal/v497/n7447/full/497036a.html
2. An article in the New York Times today concerning the Nature book and one other — neither favorable –http://www.nytimes.com/2013/05/02/books/greenbergs-book-of-woe-and-francess-saving-normal.html?ref=todayspaper&_r=0

Added 8 May ’13 The US National Institute of Mental Health (NIMH) will no longer use the Diagnostic and Statistical Manual of Mental Disorders (DSM) to guide psychiatric research, NIMH director Thomas Insel announced on 30 April. The manual has long been used as a gold standard for defining mental disorders. Insel described the DSM as ill-suited to scientific studies, and said the NIMH will now support studies that cut across DSM-defined disease categories.

But, as Ernst Mayr once said — nothing in biology makes sense except in the light of evolution. Keeping that thought in mind, what I wrote a few years ago is relevant today. Here’s the post. Although it starts off in Mathematics, it gives some history which helps explain why the DSM is the way it is.

Even so, psychiatric wisdom should be taken with a good deal of salt. A psychiatrist in my medical school class (1966) knew people who were thrown out of their psychiatric residencies because they were gay, and back then homosexuality was a psychiatric disease.

Here’s the post of 3 years ago

Reification in mathematics and medicine

Can you bring an object into existence just by naming and describing it? Well, no one has created a unicorn yet, but mathematicians and docs do it all the time. Let’s start with mathematicians, most of whom are Platonists. They don’t think they’re inventing anything, they’re just describing an external reality that is ‘out there’ but isn’t physical. So is any language an external reality, but when the last person who knows that language dies, so does the language. It will never reappear as people invent new languages, and invent them they do as the experience with deaf Nicaraguan children has shown [ Science vol. 293 pp. 1758 - 1759 '01 ]. Mathematics has been developed independently multiple times all over the world, and it’s always the same. The subject matter is out there, and not just a social construct as some say.

A fascinating book, “Naming Infinity” describes a Russian school of mathematicians who extended set theory beyond the work of the French and Germans. They literally believed that describing a mathematical object and its properties implied that the object existed (assuming the properties were consistent). The mathematicians involved were also very devout mystical Christians, who were called “Name Worshippers”. They thought that repeatedly invoking the name of Jesus would allow them to reach an ecstatic state. The rather contentious theory of the book is that their religious stance allowed them to imbue all names with powerful properties which could bring what they named into existence and this led to their extensions of set theory. Naturally the Communists hated them, and exterminated many (see p. 126). People possessed of all absolute truths dislike those possessed of a different set.

Docs bring diseases into existence all the time simply by naming them. This is why the new DSM-V (Diagnostic and Statistical Manual of Mental Disorders) of the American Psychiatric Association (APA) is so important. Is homosexuality a disease? Years ago the APA thought it was. If your teenager won’t do what you want, is this “Adolescent Defiant Disorder”? Is it a disease? It will be if the DSM-V says it is.

There are a lot of things wrong with what the DSM has become (297 disorders in 886 pages in DSM-IV), but the original impetus for the major shift that occurred with DSM-III in the 70s was excellent. So it’s time for a bit of history. Prior to that time, it was quite possible for the same individual to go to 3 psychiatric teaching hospitals in New York City and get 3 different diagnoses. Why? Because diagnosis was based on the reconstruction of the psychodynamics of the case. Just as there is no single way to interpret “Stopping by Woods on a Snowy Evening” (see the previous post), there isn’t one for a case history. Freud’s case studies are great literature, but someone else would write up the case differently.

The authors of the DSM-III decided to be more like medical docs than shrinks. In our usual state of ignorance, we docs define diseases by how they act — the symptoms, the physical signs, the clinical course. So the DSM-III abandoned the literary approach of psychodynamics and started asking what psychiatric patients looked like — were they hallucinating, did they take no pleasure in things, was there sleep disturbance, were they delusional etc. etc. As you can imagine, there was a huge uproar from the psychoanalysts.

Now no individual fits any disease exactly. There are always parts missing, and there are always additional symptoms and signs present to confuse matters. The net result was that psychiatric diagnosis became like choosing from a menu in a Chinese restaurant, so many symptoms and findings from column A, so many from column B. (Update 2013 — Having been to China for 3 weeks this year, restaurant menus over there aren’t like that).

This led to a rather atheoretical approach, but psychiatric diagnoses became far more consistent. Docs have always been doing this sort of thing and still do (look at the multiple confusing initial manifestations of what turned out to AIDS back in the 80s). Different infections were classified by how they acted, long before Pasteur proved that they were caused by micro-organisms. Back when I was running a muscular dystrophy clinic, we saw something called limb girdle muscular dystrophy , in which the patients were weak primarily in muscles about the shoulders and hips. Now we know that there are at least 13 different genetic causes of the disorder. So there are many distinct causes of the same clinical picture. This is similar to the many different genetic causes of Parkinson’s disease I talked about 2 and 3 posts earlier. At least with limb girdle muscular dystrophy it is much easier to see how the genetic defects cause muscle weakness — all of the known genetic causes involve proteins found in muscle.

Where DSM-IV (and probably DSM-V — it’s coming out later this month) went off the rails, IMHO, is the multiplicity of diagnoses they have reified. Do you really think there are 297 psychiatric disorders? Not only that, many of them are treated the same way — with an SSRI (Selective Serotonin Reuptake Inhibitor). You don’t treat all infections with the same antibiotic. This makes me wonder just how ‘real’ these diagnoses are. However in defense of them, you do treat classic Parkinsonism pretty much the same way regardless of the genetic defect causing it (and at this point we know of genetic causes of less than 10% of cases).

There is a fascinating series of articles in Science starting 12 Feb ’10 about the new DSM-V. The first is on pp. 770 – 771. One of the most interesting points is that 40% of academic inpatients receive a diagnosis of NOS (Not Otherwise Specified — e.g. not in the DSM-IV — clearly even 297 diagnoses are missing quite a bit).

But insurance companies and the government treat this stuff as holy writ. Would you really like your frisky adolescent labeled with “prepsychotic risk syndrome” which is proposed for DSM-V. Also, casting doubt on the whole enterprise, are the radical changes the DSM has undergone since it’s inception nearly 60 years ago. We’ve learned a lot about all sorts of medical diseases since then, but strokes and heart attacks back then are still strokes and heart attacks today and TB is still TB. Do these guys really know what they’re talking about, and should we allow them to reify things?

That being said, cut psychiatry some slack. Regardless of theory, there are plenty of mentally ill people out there who need help. They aren’t going to go away (or get better) any time soon. Psychiatrists (like all docs) are doing the best they can with what they know.

That’s why it’s nice to be retired and reading stuff that it is at least possible to understand — like math, physics, organic chemistry and molecular biology. But never forget that it is trivial compared to human suffering. That’s why the carnage in the drug discovery industry is so sad — there goes our only hope making things better (written in 2010, but still true in 2013).

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Comments

  • Bridgette Cantrell  On June 9, 2013 at 8:45 am

    Both in clinical practice and in large epidemiological studies, it is highly likely that any patient who receives a single DSM-IV diagnosis will, in addition, qualify for others, and the patient’s diagnostic mixture may shift over time. There is a high frequency of comorbidity—for example, many patients are diagnosed with multiple DSM-IV anxiety disorders and with DSM-IV dysthymia (chronic mild depression), major depression, or both. Many patients with an autism–related diagnosis are also diagnosed with, obsessive-compulsive disorder and attention-deficit/hyperactivity disorder. The frequency with which patients receive multiple diagnoses far outstrips what would be predicted if co-occurrence were happening simply by chance. Researchers who have made careful studies of comorbidity, such as Robert Krueger at the University of Minnesota, have found that co-occurring diagnoses tend to form stable clusters across patient populations, suggesting to some that the DSM system has drawn many unnatural boundaries within broader psychopathological states. 3 Kenneth Kendler of Virginia Commonwealth University, who has performed twin studies designed to discover genetic influences on disease risk, has found that the DSM-IV disorders that frequently co-occur with each other may do so as a result of shared genetic risk factors. 4 In addition, emerging technologies in genomics and molecular genetics have begun to identify shared “disease risk genes”—better described as variations in DNA sequences that correlate with illness—across multiple DSM diagnoses. For example, DSM-IV schizophrenia and bipolar disorder appear to share a large number, although not all, of their genetic risk factors. One significant divergence is that the genomes of many people with schizophrenia, but not bipolar disorder, may harbor disease-associated duplications and deletions of large DNA segments.

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