The Evolutionary Origin of Depression

Randolph Nesse, a psychologist and researcher in evolutionary medicine at the University of Michigan, likens the relationship between mild and clinical depression to the one between normal and chronic pain. He sees both pain and low mood as warning mechanisms and thinks that, just as understanding chronic pain means first understanding normal pain, so understanding clinical depression means understanding mild depression.

Dr Nesse’s hypothesis is that, as pain stops you doing damaging physical things, so low mood stops you doing damaging mental ones—in particular, pursuing unreachable goals. Pursuing such goals is a waste of energy and resources. Therefore, he argues, there is likely to be an evolved mechanism that identifies certain goals as unattainable and inhibits their pursuit — and he believes that low mood is at least part of that mechanism.

A study published in this month’s issue of the Journal of Personality and Social Psychology, and reported in The Economist, seems to support this theory. Carsten Wrosch from Concordia University in Montreal and Gregory Miller of the University of British Columbia studied depression in teenage girls. They measured the “goal adjustment capacities” of 97 girls aged 15-19 over the course of 19 months. They found that those women who were best able to disengage from unreachable goals not only suffered milder episodes of depression but were also far less likely to sink into more serious forms of depression.

Mild depression can therefore be seen as a natural reaction to unattainable goals and a period of reflection to adjust one's aims in life. A failure of this mechanism and an inability to change one's ambitions can lead to more severe and deeper forms of depression. Persistence and determination are seen as positive qualities in societies such as America and yet such studies show us that a dogged refusal to face reality may not be such a useful quality.

“Persistence is part of the American way of life,” says Dr Nesse. “People here are often driven to pursue overly ambitious goals, which then can lead to depression.” As this article appears in The Economist - well-known for its belief that almost everything has a free-market solution - the author ends with the rather cheerless moral that "Depression may turn out to be an inevitable price of living in a dynamic society." They fail to see that it may well be a reaction to the very values that society seems to aspire to.

To see life as merely a sequence of goals and tasks is to turn humans into flow-charts and spreadsheets. The article states that the USA has the highest rate of depression in the world. This may be due to it having the highest rate of prescribed anti-depressants but that's a wider issue of medical ethics and pharmaceutical lobbying. The idea that serious clinical depression is fundamentally maladaptive actually seems to condone the goal-driven society that this study mildly criticises. That peope may have deeper desires that are not reflected in the available societal goals should be looked at. Having the psychological tools to explore one's real ambitions is more important than being prescribed medication so that one may refocus on acceptable goals. But, alas, there is little money to be made from meditation compared to medication.

One thing to take from this study is that depression is indeed a sign that something is not right in one's emotional life. It is the cue to take a long hard deep look at oneself. If the tunnel goes deeper than one expected, then so be it, but what else is there to do in life than to become one's true self?