With the new iteration in use for a few years now, I thought this might be a good time for a brief reminder about its limitations.
Most so-called ‘mental’ illnesses are still defined in terms of their symptoms, rather than a clear understanding of the physical processes that likely create those symptoms. In a sense we’re just describing disorders that we only partly understand. Science’s inability to point to a specific cause is sometimes used to argue that mental illnesses don’t exist, but that’s a weak argument given the array of evidence to the contrary. History is full of disorders that were misunderstood simply because the science of the time was inadequate to the task — tertiary syphilis, for example, which at one time packed the asylums of Europe.
Still, it’s true that the DSM is a consensus document that emerges from vigorous debate among experts about the interpretation of available research. Such debates by their nature sometimes arrive at the wrong conclusion (imagine philosophers once debating the Earth’s relationship to the Sun.) The debate is often fierce and unending, as illustrated by this article from one of the DSM’s active participants.
Without taking sides, some things I’ve learned about the DSM in its previous versions:
- There’s a tendency among clinicians to take DSM criteria too seriously. I recall one very bright young social worker insisting that ‘alcoholism’ didn’t exist because the term wasn’t in the current DSM. But the DSM describes illnesses, it doesn’t really explain them. And descriptions change as more becomes known.
- One critique of DSM criteria is that validity is often sacrificed to obtain reliability. Validity means accuracy of measurement, while reliability is the ability to consistently replicate the results. Both are important, but the ability to get the same result whenever a set of criteria is applied isn’t proof that the criteria were valid in the first place.
- And of course, there’s always the question of objectivity. Qualitative research hopes only to demonstrate impartiality; nobody pretends that a researcher can make those sorts of subjective assessments without affecting the outcome. That’s where the influence of big money comes up, or the unending pressure to publish more findings.
It’s a debate well above my pay grade — I seem to be saying that a lot lately — but one that’s a long, long way from over.