Monday, June 03, 2013
More on psychiatric diagnosis
Now that we've laid out some foundational issues, this seems a good time to go back to the DSM and finish constructing our deconstruction. Various categories of psychiatric diagnosis present quite different sets of issues. My friend Gary, in The Book of Woe, raises most of them in one way or another but he doesn't march us through them systematically -- it's not that kind of book. I'm a more boring sort of writer, however, so I'll just put the ducks in a row and knock them down.
There are indeed various things that can go wrong with our brains which have all the right stuff to be called a specific disease, and treated like one (to the extent treatment is possible). These would include Alzheimer's, Parkinson's, stroke, brain tumors, traumatic brain injuries, encephalitis of whatever cause. Here, we can find some gross abnormality in the perceptible physical appearance of the brain, and we can link these consistently and explicably to symptoms which are clearly undesirable and out of the ordinary. The bad news for the APA is that none of these are really psychiatric disorders. Neurologists, oncologists, surgeons, infectious disease specialists get the fees.
Then there's addiction, which seems to have a lot of the right stuff. A fairly well accepted theory of addiction to many commonly indicted chemicals is that they essentially hijack a specific circuitry in the brain that controls motivation, mediated by the neurotransmitter dopamine. There isn't exactly a lab test for this but the receptors involved are known. Effective chemical treatments are coming along for alcoholism and we also have designer opioids that can be titrated to satisfy craving without producing sedation or euphoria. (Other drugs which are sometimes abused or can produce dependency work in other ways, but again there is basic understanding of their mechanisms.)
The real debate here is whether the "disease" concept is the most practically useful, or perhaps morally appropriate, way to think about addiction. People who invite harm or risk by their ingestion of psychoactive chemicals have very different patterns of consumption, from a little bit all the time to occasional major binges; and as many people argue, it isn't the bad chemicals that produce addiction, it's usually other problems people have such as not having something else they want to do badly enough to motivate being sober. In this view, addiction isn't really an essential disease but rather a symptom of not having a life, as it were. More controversial, from the point of view of the neuroscience, the etiology, and the ontology, are proposed non-chemical addictions such as gambling, food, shopping and sex. If you accept that these can also be addictions, then the disease label seems even more problematic. The diagnosis is even fuzzier, especially since total abstinence from some of these activities is itself either abnormal or fatal; and the question of morality and personal responsibility becomes more vexed for many.
I don't have a right answer here. If the disease concept works for you in these instances, use it. If you'd rather think of it another way, that's also defensible.
Then we have your so-called "major" mental "disorders," which are more or less schizophrenia and what is now becoming a penumbra of variously named psychotic conditions; bipolar disorder; and major depression. That these seem to have mutual inter-heritability suggests some (completely unknown) common etiological core, which helps make the case for disease. Schizophrenia has a classic presentation with onset in late adolescence or early adulthood; and a complex of symptoms including hallucinations, disordered speech and thinking, delusions, and deficits in social interaction. There are drugs that can calm down the hallucinations and delusions, although they do leave people with flat affect and apathy, and can have terrible physical side effects. (The drugs don't tell us anything about the cause of schizophrenia however. By analogy, the pain of a broken leg is not caused by morphine deficiency.)
All this argues for the ontological status of schizophrenia as a disease. It seems to be a reasonably identifiable specific thing, and you definitely don't want it. It turns out, however -- and this came as news to me -- that the diagnostic reliability of schizophrenia is not nearly what you might think. Many people don't exactly have all the symptoms. Ted Kakzcynski, for example (the Unabomber) was given a diagnosis of schizophrenia, but he does not have disordered speech -- on the contrary, he's pretty good with words -- and he doesn't hallucinate. Arguing that he is delusional gets you onto very thin ice -- he has opinions which are unconventional and subversive, but so do I. He doesn't think they're being beamed into his brain from Aldebaran. That he has the same "disease" as Jared Loughner is highly questionable.
In fact people's diagnoses can cycle among the major mental disorders and their sub-types, and diagnosticians will come up with different answers for the same person. One strongly suspects that there is some sort of common etiological core here, and in any case that some day we may have a specific physical marker that corresponds to these presentations, or perhaps markers that can differentiate among them. The drugs we have for these entities, be they legitimate diseases or not, you would rather not take unless the alternative is even worse, which it often is. So the disease frame seems pretty defensible, but the attempt at sub-classification and naming, at the current state of knowledge, not so much. The basic problem here, then, is ignorance.
Next I'll go on to depression and other affective disorders; behavioral diagnoses; and personality disorders.