Thursday, April 05, 2007

Taxing Taxonomy


During our last podcast we answered a question about whether or not pedophilia was a disease. Another earlier question we addressed was whether or not schizotypal personality disorder was related to schizophrenia. Our readers/listeners aren't the only ones questioning how to approach psychiatric diagnoses.

Today's American Journal of Psychiatry has a dense article on the "Conceptual Taxonomy of Psychiatric Disorders". It's an overview of philosophical approaches to the classification of mental disorders written by the folks working on DSM-V. The abstract alone is worthy of a philosophy major. I made it through the entire article but I promise never to bring it up on the podcast. The article considers whether or not psychiatric disorders are more like chemical elements (they exist naturally outside of ourselves, have common properties, and must be defined by exploration and discovery---known as essentialism) or whether at the other extreme they are created arbitrarily by mutual agreement separate from any underlying truths---known as nominalism.

And that's only one of the six "dimensions of categorization" they propose applying to current medical models. Thank goodness Dinah and I only had to consider the four perspectives. (Although I have to admit I enjoyed the part where they compared making a diagnosis across a continuum to slicing a meatloaf!)

Another diagnosis-related issue was addressed in a recent New York Times article discussing a study of depressive symptoms among the bereaved. In an article published in the Archives of General Psychiatry researchers compared bereaved depressed subjects with depressed patients suffering from other losses with regard to number and duration of symptoms, functional impairment and other measures. They found no difference between the two groups and concluded that many life losses could be used as an exclusion criteria for major depression. (My translation: "Of course you're depressed, look what you've been through.")

I think this article will serve to muddy the waters rather than clarify them. I deal with this issue frequently among my patients after a new diagnosis of major depression: "Of course I'm depressed, look where I am!" In fact the majority of prisoners are not clinically depressed. Most of the death row inmates I've seen have not been clinically depressed. All this study does is support the idea that psychosocial stress can precipitate disease---we already knew that. It supports the idea that current diagnostic criteria can define a syndrome separate from causation, which is a good thing. The one thing it doesn't address---at all---is how the disorder should be treated. And that's the main thing the New York Times article talked about.

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Maybe I Am A Therapist

Just a couple of vignettes from today that I enjoyed:

Patient: "How do you know that bipolar disorder is a disease?"

Me: I go on about genetics and chromosomes and changes in neurotransmitters and response to medication. Then I do what I should have done to begin with: I ask the patient what he thinks is the cause of his multiple hospitalizations and suicide attempts.

Patient: "I think it's a government conspiracy."

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(During intake assessment patient reveals he just had a bad phone call home. Brief crisis intervention provided.)

Patient: "Hey doc, can I come back down again and talk to you sometime?"

Me: "We have psychologists here if you'd like some counselling. I can set you up with one. I just work with medications; I don't really do counselling myself."

Patient: "Why not? You're a good one!"