A great new piece by Johah Lehrer in this weekend’s upcoming New York Times Magazine, touching on everything from Charles Darwin to David Foster Wallace and everywhere in between, looking for an answer as to why depression exists, and paradoxically, what positive functions it might serve at times.  This is one I’ll no doubt be quoting from quite a lot on here, and encouraging my own clients to read immediately. And I urge all of you to do the same: find some time this weekend and sit down with this article.

Excerpt:

For Darwin, depression was a clarifying force, focusing the mind on its most essential problems. In his autobiography, he speculated on the purpose of such misery; his evolutionary theory was shadowed by his own life story. “Pain or suffering of any kind,” he wrote, “if long continued, causes depression and lessens the power of action, yet it is well adapted to make a creature guard itself against any great or sudden evil.” And so sorrow was explained away, because pleasure was not enough. Sometimes, Darwin wrote, it is the sadness that informs as it “leads an animal to pursue that course of action which is most beneficial.” The darkness was a kind of light.

The mystery of depression is not that it exists — the mind, like the flesh, is prone to malfunction. Instead, the paradox of depression has long been its prevalence. While most mental illnesses are extremely rare — schizophrenia, for example, is seen in less than 1 percent of the population — depression is everywhere, as inescapable as the common cold. Every year, approximately 7 percent of us will be afflicted to some degree by the awful mental state that William Styron described as a “gray drizzle of horror … a storm of murk.” Obsessed with our pain, we will retreat from everything. We will stop eating, unless we start eating too much. Sex will lose its appeal; sleep will become a frustrating pursuit. We will always be tired, even though we will do less and less. We will think a lot about death.

The persistence of this affliction — and the fact that it seemed to be heritable — posed a serious challenge to Darwin’s new evolutionary theory. If depression was a disorder, then evolution had made a tragic mistake, allowing an illness that impedes reproduction — it leads people to stop having sex and consider suicide — to spread throughout the population. For some unknown reason, the modern human mind is tilted toward sadness and, as we’ve now come to think, needs drugs to rescue itself.

The alternative, of course, is that depression has a secret purpose and our medical interventions are making a bad situation even worse. Like a fever that helps the immune system fight off infection — increased body temperature sends white blood cells into overdrive — depression might be an unpleasant yet adaptive response to affliction. Maybe Darwin was right. We suffer — we suffer terribly — but we don’t suffer in vain.