The Los Angeles Times recently ran a story about evolutionary psychology as it relates to depression. (Thanks to Cashew for pointing this out!) The article discusses the evolutionary approach that some researchers are taking not only to understanding depression but also to treating it. It’s still early times for this kind of work, so this is an engaging introduction to an obviously dynamic field with more questions than answers at this point.
I read somewhere once that depression might have originated as an adaptive urge to strategic withdrawal to conserve energy and regroup after a setback of some kind, but that’s only one theory. There are several possible types of evolutionary explanations for mental illness in general: that it might have been adaptive because the behaviors it causes evoke care and attention from others when we need it; conversely, that it is a measure of how badly our current lifestyles fit us due to the fact that we evolved for a different sort of physical and social environment than the one we live in today; or perhaps that it is a result of a slow accumulation of mutations.
The explanation about a mismatch between how we live now and how we used to live is familiar because something similar has been used to explain some of our current health problems—e.g., that we evolved in an environment in which fats and sugars were much rarer and signaled a rich energy source, so we developed a strong response to them that works against us now that we are surrounded by easily available sweet fatty foods. And there’s a therapeutic approach to depression in which patients are encouraged “to live more like their Paleolithic ancestors” (e.g., more aerobic exercise, more sleep, more positive social interaction). Personally I’ve found that regular exercise is one of the best ways to keep the blues at bay; in fact I’ve wondered if having fewer exercise opportunities during the winter might not contribute a bit to seasonal affective disorder (SAD) for some people. (Which reminds me that awhile back I wrote this essay, which mentions a possible evolutionary explanation for SAD.)
On the other hand, I’ve always been drawn to the idea that sometimes depression is analogous to physical pain that can alert you to something wrong that needs to be fixed, or simply to a situation where the best course of action is to withdraw. However, depression (and physical pain for that matter) is often complicated, and it’s hard to tell when the pain is something to accept and live through and learn from, and when you need some kind of intervention (behavioral, pharmaceutical, or otherwise) to set things right.
Some of the therapies described sound to me like they’re only somewhat loosely connected with evolutionary psychology. For years therapists have been guiding their clients through imaginary conversations with parents, siblings, ex-lovers, etc., to finish off or rework old emotional business, for example, and I’m not sure I see how that relates to evolutionary psychology. Robert Neimeyer of the University of Memphis was quoted in the article as saying that maybe evolutionary explanations work better at explaining average human behavior than individual problems, which makes a lot of sense to me, so I wonder how useful an evolutionary approach is going to be in the long run in developing therapies.
But treating depression or other emotional disorders is still more of an art than a science, and I’m glad to see that people are working on a better understanding. I’m guessing that any new therapies that come out of it probably will help at least some of the people some of the time. And with any luck we’ll learn something about how we got to be the way we are.
