Friday, December 4, 2009

Why Psychiatry May Sometimes Need “Fuzzy” Diagnoses

“Well, while I’m here, I’ll do the work—and what’s the work? To ease the pain of living . . .”
—Allen Ginsberg

"Many words . . . don't have a strict meaning. But this is not a defect. To think it is would be like saying that the light of my reading lamp is no real light at all, because it has no sharp boundary."
—Ludwig Wittgenstein, The Blue and Brown Books

As a general proposition, most scientists and physicians prefer sharpness to fuzziness, at least when it comes to defining terms. I generally share this view, as regards psychiatric diagnosis, but only up to a point. That point is defined by the well-being of my patient—and sometimes this may call for a “fuzzy” diagnosis.

To understand why this is so, consider the following thought experiment. Imagine that we have a set of psychiatric signs and symptoms, designated as A through F. Suppose that if we select “A,B,C,D,E” as constituting our identified “Syndrome X,” we can correlate it with a specific pathophysiology and even with a specific genetic anomaly. Sounds terrific, right? And all so very “scientific”! But suppose that the syndrome, so defined, corresponds poorly to our patients’ subjective experience of distress; and furthermore, that the “ABCDE” syndrome does not lend itself well to any effective treatment.

Now imagine we start with the same A through F signs and symptoms, but we decide to group them as either “A,B,C,D,E” or as “B,C,D,E, F.” We are, in other words, making our definition of Syndrome X “fuzzier.” We now find that Syndrome X no longer corresponds as well to a particular pathophysiology or genetic defect, but that it better captures our patients’ subjective experience, and also lends itself to an effective treatment. In short, the fuzzier syndrome allows us to reduce our patients’ degree of suffering and incapacity to a greater extent than did the “sharp” ABCDE category. Which syndrome is more “real”—the “sharp” or the “fuzzy” one? Which is more pragmatically useful? And which syndrome leads us to more humane medical care, consistent with our ethical responsibilities as physicians?