Psychologists think they've found the purpose of depression

At the center of Hutson’s piece is Paul Andrews, an evolutionary psychologist at McMaster University in Canada. Andrews argues that depression may be “an adaptation for analyzing complex problems.” He sees it in the condition’s bouquet of symptoms, which include “anhedonia,” or an inability to feel much pleasure; people who are depressed ruminate frequently, often in spirals; and they get more REM sleep, a phase associated with memory consolidation. This reflects an evolutionary design, the argument goes, one that’s to, as Hutson summarizes, “pull us away from the normal pursuits of life and focus us on understanding or solving the one underlying problem that triggered the depressive episode.” Like, say, a “failed” relationship. The episode, then, is a sort of altered state, one different from the hum of daily life, one that’s supposed to get you to pay attention to whatever wounding led to the upset. For example, 80 percent of subjects in a 61-person study of depression found that they perceived some benefit from rumination, mostly assessing problems and preventing future mistakes.

For now, Andrews’s “analytical rumination hypothesis” is just that, a hypothesis, a term that combines the Greek hypo (under) with -thesis (placing). It’s a concept, an observation, one that acts as a structure for further inquiry. Still, already, there is something very powerful, and even actionable, in reconceptualizing (some) depressive episodes as having a function, as presenting a quest toward understanding for the sufferer to undertake. Other research helps to refract the light being shined here: Laura King, a psychologist at the University of Missouri, has spent a couple decades studying people’s experiences of meaning in life, and she told me in an interview at this year’s Society for Personality and Social Psychology meeting that the meaning people derive from difficult experiences depends not on the amount that they’re suffered, but the extent of reflection — or meaning-making — they’ve done on what prompted a given nadir. Following this logic, if the job of a depressive episode is to figure out what’s gone awry, what emotional knots need to be untangled, what attachment patterns need to be identified and addressed, then antidepressants are an incomplete treatment, just like you wouldn’t prescribe Percocet to a heal a broken ankle without also supplying a cast.