Jonah Lehrer's thoughtful piece notes that depression has long been linked to creativity. He mentions that one survey found 80% of students at the Iowa Writers Workshop exhibited some type of depression (I do have to wonder whether the survey took place during an Iowa winter). But the throes of depression haven't been known for improving critical thinking skills — until recently. Specifically, studies have found that depressed people show increased activity in a brain area called the left ventrolateral prefrontal cortex (VLPFC), which is also associated with "intense focus." Psychiatrist Andy Thomson and psychologist Paul Andrews believe the VLPFC's involvement may point to a link between rumination — a key part of depressive thinking in which sufferers revisit painful thoughts over and over — and actually arriving at solutions to life's problems. Lehrer writes that increased VLPFC activity leads to "an extremely analytical style of thinking" in which people "tend to think in a more deliberate fashion, breaking down their complex problems into their simpler parts." He continues,
Andrews and Thomson see depression as a way of bolstering our feeble analytical skills, making it easier to pay continuous attention to a difficult dilemma. The downcast mood and activation of the VLPFC are part of a "coordinated system" that, Andrews and Thomson say, exists "for the specific purpose of effectively analyzing the complex life problem that triggered the depression." If depression didn't exist - if we didn't react to stress and trauma with endless ruminations - then we would be less likely to solve our predicaments. Wisdom isn't cheap, and we pay for it with pain.
The idea has many detractors — Peter Kramer, author of Listening to Prozac, argues that Andrews and Thomson really only consider people whose depression is a response to a specific life event, and not those who suffer from "chronic depression and the sort of self-hating, paralyzing, hopeless, circular rumination it inspires." And Andrews and Thomson themselves admit that "sometimes the symptoms can spiral out of control" — depression may help some people solve problems, but it paralyzes others, making them incapable of doing anything at all. As anyone who's struggled with depression in a variety of situations knows, sometimes the bad feelings may be trying to tell you something concrete about your life, and sometimes they're just not.
What's really interesting about Andrews and Thomson's research isn't that it proves depression is always productive — even they don't claim that. Rather, it's part of a larger drive to explain why the disorder, which seems so maladaptive, remains so common in our species. This drive recalls some of Temple Grandin's ideas about autism. Grandin doesn't argue that low-functioning autism is a blessing for children and families who deal with it. Rather, she says "autism genetics" are useful in the population as a whole. She once said that "if you got rid of all the autism genetics, you wouldn't have science or art," and it may be true that the same genes that can keep a severely autistic child from learning to talk can, in different combinations, produce great creativity and innovation. By the same token, perhaps some of the mental processes involved in depression persist because they can be adaptive in small doses. If humanity didn't have the capacity for rumination at all, perhaps we would flounder, unable to change our lives or make big decisions.
In a recent CNN interview, Grandin said,
We need to be working on using different kinds of thinking. Visual thinkers are good at one kind of thing, the pattern kind of thinkers are going to be super good at programming, word thinkers know lots of facts. We need to be developing kids' strengths [...]
In a similar vein, treating depression may require that we understand that people's brains work in different ways. For some, rumination may be a means to an end — Thomson describes a patient whose depression may have been related to family pressures, and for whom his goal was to "speed along the rumination process," not stop it dead. But for others, rumination may be a cycle of pain and self-loathing that actually prevents problem-solving. The challenge is to develop effective treatments for each — and to recognize the ways in which depression, like autism, may reveal the human brain's strengths as well as its weaknesses.
Note: The image depicts a brain stimulation device studied for the treatment of severe depression.