Their conclusion was that those who experienced mild depressive symptoms could, indeed, disengage more easily from unreachable goals. That supports Dr Nesse’s hypothesis. But the new study also found a remarkable corollary: those women who could disengage from the unattainable proved less likely to suffer more serious depression in the long run.

Mild depressive symptoms can therefore be seen as a natural part of dealing with failure in young adulthood. They set in when a goal is identified as unreachable and lead to a decline in motivation. In this period of low motivation, energy is saved and new goals can be found. If this mechanism does not function properly, though, severe depression can be the consequence.

The importance of giving up inappropriate goals has already been demonstrated by Dr Wrosch. Two years ago he and his colleagues published a study in which they showed that those teenagers who were better at doing so had a lower concentration of C-reactive protein, a substance made in response to inflammation and associated with an elevated risk of diabetes and cardiovascular disease. Dr Wrosch thus concludes that it is healthy to give up overly ambitious goals. Persistence, though necessary for success and considered a virtue by many, can also have a negative impact on health.

Dr Nesse believes that persistence is a reason for the exceptional level of clinical depression in America — the country that has the highest depression rate in the world. “Persistence is part of the American way of life,” he says. “People here are often driven to pursue overly ambitious goals, which then can lead to depression.” He admits that this is still an unproven hypothesis, but it is one worth considering. Depression may turn out to be an inevitable price of living in a dynamic society.

... contd.