The Spectral Boom in Depression

[Cross-posted to Happiness and Public Policy]

I heard on the news this morning that Aetna is planning to cover depression treatments in some of their health plans. The New York Times reports:

Under the plan, Aetna will pay primary care doctors additional fees to screen patients for depression and to provide follow-up consultations for patients who are either put on antidepressants or, in more severe cases, referred to psychiatrists or psychologists. Aetna plans eventually to offer the program nationwide.

The additional costs of identifying and treating depression, Aetna said, can in many cases be more than offset in avoiding the larger financial costs associated with the disease – and the higher medical expenses that often arise when other chronic conditions, like diabetes and heart disease, are compounded by depression. Depressed patients with such diseases often stop taking their medications or fail to carry out recommended exercise and diets.

Researchers said that 33 million Americans require treatment for depression each year, and at least one in six people have the disease, with varying degrees of severity, at some point in their lives.

Now, it's certainly awful to be sad, listless, and unmotivated. (I've been there. You too, probably.) And I think it can be a very good thing to take mood-enhancing drugs when you feel low. Depression certainly makes you feel uneasy, but is it really a disease?

The “paradox” of prosperity crowd makes hay out of rising rates of depression diagnosis. Lane, in The Loss of Happiness, for example, characterizes it as an “epidemic.” However, it is at least as likely as not that the “epidemic of depression” is an artifact of, among other things, (1) an egregiously lax and ill-defined diagnostic category, (2) shifting cultural norms about the range of normal function, (3) and diagnostic zealousness driven by the interests of the mental health profession (we're like real doctors and we deserve to be paid like it!) and (4) pharmaceutical companies who want to sell huge quantitites of mood-enhancing drugs to people who inhabit a culture that doesn't think it's OK to take drugs unless you're “sick.”

This grandly evasive passage from Lane captures the thinness of the evidence and the desperation to build mansions of conjecture upon it:

Rising depression of this magnitude is a tragedy for any civilization, but the epidemological study of these tragic phenomena is dependent on measurement instruments that are being perfected, and the longitudinal data are in their infancy.

That is to say, “We can't really say with any certainty whether the incidence of depression is really rising or not, but my book will be much more exciting if I act like I know that civilization is in the throes of tragedy.”

As an antidote to depression hysterics, I strongly recommend “The Age of Depression,” by Allan Horwitz and Jerome Wakefield in the penultimate edition of the Public Interest.

After examining the epidemiological numbers, they write:

No plausible theory of depressive disorder, whether genetic, psychological, or social, can explain why rates of depression would have increased so much in such a short period of time. Instead, the explanation appears to lie in changes in the ways that physicians, mental-health professionals, and people themselves characterize and diagnose their mental states. There are, and always have been, true depressive disorders, in which the response to loss goes awry and takes on a debilitating life of its own. But in the past, such disorders were distinguished from normal sadness that arises in response to life's vicissitudes. That traditional, common-sense distinction has broken down in contemporary psychiatry, resulting in the conflation of depressive disorders with normal sadness. The sources and social implications of this breakdown are as yet largely unappreciated. [emphasis added]

Horwitz and Wakfield provide a fascinating history of depression through the ages and an extremely illuminating account of how theory wars over the DSM categories led to an overly inclusive “theory neutral” clinical conception of depression.

The basic flaw, then, is that the DSM-IV fails to exclude from the disorder category sadness reactions to events other than death of a loved one that are intense enough to meet the DSM-IV's criteria but are still normal reactions. The age of depressive disorder in which we find ourselves today is partly an artifact of a logical error.

The section on “The Constituencies for Depression” is also key to understanding the political and financial stakes surrounding medicalization of sadness. For example,

the DSM's criteria are used in virtually all of the thousands of studies done in recent years on depression, and many researchers' careers are built around these studies. Consequently, any major reconceptualization of diagnostic criteria would throw all that into doubt. Adequately distinguishing normal sadness from depressive disorder could also possibly narrow opportunities for research funding, especially if the NIMH followed suit by focusing its efforts on true disorder.

And perhaps more important:

Many private-practice clinicians will readily admit that a sizable proportion of their “depression” caseload consists of individuals who are psychiatrically normal but experiencing stressful life events. To obtain reimbursement for the treatment of such patients, the clinician must classify the individual within a DSM category of disorder, and depression is one of the more commonly used and easier ones to justify given the ubiquity of its symptoms. The result is a strange case of two “wrongs” seemingly making a “right”: The DSM provides flawed criteria that do not adequately distinguish disorder from nondisorder; the clinicians, knowingly or unknowingly, incorrectly classifies a normal individual as disordered (Why should the clinician question a diagnosis officially sanctioned by the DSM?); and the patient receives desired treatment for which the therapist is reimbursed.

The news about Aetna simply illustrates how much many people have to lose should depression be recategorized in order to become scientifically legitimate. In any case, the Horwitz and Wakefield paper is very important.

If we put the overdiagnosis of depression together with the framing effects of self-reporting discussed yesterday, we arrive at the possibility that we are happier than we think, possibly even happier than we have ever been.

Also recommended:

Stanford Encyclopedia of Philosophy entry on “mental illness” by Christian Perring.

Allan Horwitz, Creating Mental Illness

Jerome C. Wakefield,”The concept of mental disorder: On the boundary between biological facts and social value,” A merican Psychologist. 1992 Mar Vol 47(3) 373-388.

[Cross-posted to Happiness and Public Policy. Please leave your comments there.]