Depression and Evolution

Posted on February 23, 2005 in Depression Evolution & Creation

For some reason, I lifted my copy of Michael Shermer’s The Science of Good and Evil : Why People Cheat, Gossip, Care, Share, and Follow the Golden Rule from the bookshelf and looked up “depression” in the index. There was a single citation, on page 129 where Shermer cites Peggy La Cerra and Roger Bingham’s The Origin of Minds : Evolution, Uniqueness, and the New Science of the Self. La Cerra and Bingham seek to understand the adaptive advantage of various features and behaviors of the brain. Shermer sums up and cites them on our lugubriousness:

The symptoms of depression — restlessness, agitation, disturbed sleeping and eating, impaired concentration, and loss of motivation — are not signs of an illness; rather they represent an adaptive response to do something different in your life. “Because behavior is so enormously expensive engetically, the best thing a person in this situation can do is to stop what he has been doing, reconfigure his life, and try to fomulate a more viable trajectory into the future.” Why would this intelligence system have evolved? “If you were an ancestral human who was being exploited by another individual or group of individuals, a complete behavior shutdown could abruptly force a renegotiation of the inequitable social relationship.” Even in the modern world, [My note: ESPECIALLY in the modern world?] depression “serves as a wake-up call, prodding people to abandon dead-end jobs and relationships.”

I have mixed feelings about this. Certainly I know people who fit this model. On the other hand, I know people who don’t. La Cerra and Bingham’s conclusions are based on a model of depression which accounts for some varieties of The Beast, but not others. For some of us, depression is a lifelong struggle: can it be that we never ever will fit in anywhere? Are we doing the species a favor by offing ourselves because we can’t find a way to fit ourselves into society?

That’s the danger of following this belief to its logical extreme. And that is why I review evolutionary psychological explanations of my disease with caution. I see here a typical failing of “adaptive response” explanations of everything. Like all clockwork universe models, they assume an “everything is for the best in this best of all possible worlds” mentality. But those of us who suffer from mood disorders know how counterproducitve they can be, how slow the return to society is — even if we do start taking steps to change our lives. Depression exists because it does not kill us off before we can breed. Seeing depression as a disease — hormonal imbalance in the brain — makes much more sense to me than this scientified “Ah, just snap out of it” model. Shermer — who I feel has many good things to say — has obviously never suffered from depression as I and countless others have. If he did, he’d see the fallacy and lack of compassion in La Cerra and Bingham’s evolutionary psychology straight off.