Wonderful behavioral science writer Jonah Lehrer (Proust Was a Neuroscientist) writes for the New York Times Magazine on the idea that depression may be adaptive. It is not a new idea; I have followed the intriguing literature about possible evolutionary reasons for the persistence of depression ever since I was a psychiatric resident troubled by how readily we in the field want to obliterate any signs of the condition whenever our patients present with it. Some theories have focused on the advantages of resource preservation, given the social isolation, decreased motivation and lessened self-indulgence the depressed person displays. It has also been suggested that the depressive alteration in cognition, in the direction of impaired self-esteem, decreased sense of efficacy and control over one’s circumstances, and pessimism , may actually be more realistic, at least in some circulstances, than the rose-colored glasses with which we usually walk around.
But recent research adds neuropsychological evidence of increased brain activity in depressed patient in regions of the prefrontal cortex associated with problem-solving, proportional to the degree of depression. It is certainly not the whole explanation, as critics counter, because some of the maladaptive impact of depression, including poor self-care, impairment in childrearing, increased susceptibility to other illness, and last but not least suicide, will outweigh the problem-solving advantages it might confer. Furthermore, there are many different kids of depression both in terms of precipitant and symptomatology. At one extreme, a person may become depressed in response to an acute recent loss (or even a future anticipated one); on the other hand, some people can develop either a dense acute depression or a smouldering chronic one without substantial stresses or losses. The imprecisions in both the lay person’s use of the term depression and its more technical clincal utilization muddy the waters in this regard.
Still, it is worth asking why a condition that is so painful and takes such a heavy toll would persist if it were not at least some of the time of some use… and whether, at least some of the time, we do more harm than good in leaping to treat it. Except, of course, the unequivocal good done to the pockets of the shareholders and executives of the pharmaceutical companies, reaping the profits from the explosive growth in antidepressant sales of the last few decades. (New York Times Magazine)