The Benefits of Depression: Boosting Brain Power?

Jonah Lehrer's article "Depression's Upside" explains that “The Victorians had many names for depression, and Charles Darwin used them all. Darwin attempted to explain his symptoms. There were his “fits” brought on by “excitements,” “flurries” leading to an “uncomfortable palpitation of the heart” and “air fatigues” that triggered his “head symptoms.” In one particularly pitiful letter, written to a specialist in “psychological medicine,” he confessed to “extreme spasmodic daily and nightly flatulence” and “hysterical crying” whenever Emma, his devoted wife, left him alone.”

Darwin himself was most troubled by his recurring mental problems. His depression left him “not able to do anything one day out of three,” choking on his “bitter mortification.” He despaired of the weakness of mind that ran in his family. “The ‘race is for the strong,’ ” Darwin wrote. “I shall probably do little more but be content to admire the strides others made in Science.”  Darwin actually may have used his symptoms to succeed in science, by allowing him to withdraw into his work.  Darwin stated that “Work is the only thing which makes life endurable to me,” and he later remarked that it was his “sole enjoyment in life.”

For Darwin, depression was a way of focusing his mind.  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.”

Depression:  The Common Cold of The Mind

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. The most common statistic is that 7 to 10 percent will be afflicted to some degree by depression. 

Lehrer explains that, “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.”

Could it be that there is a different reason for the commonness of depression?  Lehrer questions whether depression may have a secret purpose and if our use of medicines and medical treatment are interfering with an evolutionary adaptation.

Lehrer interviewed a psychiatrist, and he reported that “Andy Thompson is a psychiatrist at the University of Virginia. He has a scruffy gray beard and steep cheekbones. When Thomson talks, he tends to close his eyes, as if he needs to concentrate on what he’s saying. But mostly what he does is listen: For the last 32 years, Thomson has been tending to his private practice in Charlottesville. “I tend to get the real hard cases,” Thomson told me recently. “A lot of the people I see have already tried multiple treatments. They arrive without much hope.” On one of the days I spent with Thomson earlier this winter, he checked his phone constantly for e-mail updates. A patient of his on “welfare watch” who was required to check in with him regularly had not done so, and Thomson was worried. “I’ve never gotten used to treating patients in mental pain,” he said. “Maybe it’s because every story is unique. You see one case of iron-deficiency anemia, you’ve seen them all. But the people who walk into my office are all hurting for a different reason.”  

People Who Ruminate Tend to Be Depressed

In the late 1990s, Thomson became interested in evolutionary psychology and the evolution of the brain.  In 2004, Thomson met Paul Andrews, an evolutionary psychologist at Virginia Commonwealth University, who had long been interested in the depression paradox — why a disorder that’s so costly is also so common.  They began a discussion about the brain and depression and began by focusing on the thought process that defines the disorder, which is known as rumination.  In recent decades, psychiatry has come to see rumination as a dangerous mental habit, because it leads people to fixate on their flaws and problems, thus extending their negative moods.  The concept is that the brain keeps having intrusive and negative thoughts, which reinforce the depressive symptoms.  The bleakness of this thought process helps explain why, according to the Yale psychologist Susan Nolen-Hoeksema, people with “ruminative tendencies” are more likely to become depressed. 

They’re also more likely to become unnerved by stressful events: for instance, Nolen-Hoeksema found that residents of San Francisco who self-identified as ruminators showed significantly more depressive symptoms after the 1989 Loma Prieta earthquake. And then there are the cognitive deficits. Lehrer explains that, “Because rumination hijacks the stream of consciousness — we become exquisitely attentive to our pain — numerous studies have found that depressed subjects struggle to think about anything else, just like Wallace’s character. The end result is poor performance on tests for memory and executive function, especially when the task involves lots of information. (These deficits disappear when test subjects are first distracted from their depression and thus better able to focus on the exercise.) Such research has reinforced the view that rumination is a useless kind of pessimism, a perfect waste of mental energy.”

Andrew and Thompson agreed that rumination is often a response to a specific psychological blow, like the death of a loved one or the loss of a job. (Darwin was plunged into a debilitating grief after his 10-year-old daughter, Annie, died following a bout of scarlet fever).  Andrews says that “(Ruminations) it’s usually a response to something real, a real setback. It didn’t seem right that the brain would go haywire just when we need it most.”

Lehrer encourages us to use our imagination to better understand depression: “Imagine, for instance, a depression triggered by a bitter divorce. The ruminations might take the form of regret (“I should have been a better spouse”), recurring counterfactuals (“What if I hadn’t had my affair?”) and anxiety about the future (“How will the kids deal with it? Can I afford my alimony payments?”). While such thoughts reinforce the depression — that’s why therapists try to stop the ruminative cycle — Andrews and Thomson wondered if they might also help people prepare for bachelorhood or allow people to learn from their mistakes. “I started thinking about how, even if you are depressed for a few months, the depression might be worth it if it helps you better understand social relationships,” Andrews says. “Maybe you realize you need to be less rigid or more loving. Those are insights that can come out of depression, and they can be very valuable.”

Andrews and Thompson had a very different view on depression.  They suggested that maybe there was a benefit to depression.  They wanted to show how rumination might lead to improved outcomes, specifically when it comes to solving life’s most difficult dilemmas. They focused on the specific symptoms of core features of depression.  These include:  decrease in pleasure, change in eating, decrease in desire for sex and social interactions. According to Andrews and Thomson, they believed that positive in depression was that the symptoms “reduced the possibility of becoming distracted from the pressing problem.”  Andrews and Thompson  theorized that the ability for intense focus comes from a part on a brain area called the left ventrolateral prefrontal cortex (VLPFC), which is located a few inches behind the forehead. While this area has been associated with a wide variety of mental talents, like conceptual knowledge and verb conjugation, it seems to be especially important for maintaining attention. Experiments show that neurons in the VLPFC must fire continuously to keep us on task so that we don’t become sidetracked by irrelevant information. Furthermore, deficits in the VLPFC have been associated with attention-deficit disorder. 

The Benefits of Depression

They suggested that maybe there was a benefit to depression.  Andrews and Thompson wanted to show how rumination might lead to improved outcomes, specifically when it comes to solving life’s most difficult dilemmas. They focused on the specific symptoms of core features of depression, which include:  decrease in pleasure, change in eating, decrease in desire for sex and social interactions. According to Andrews and Thomson, they believed that positive in depression was that the symptoms “reduced the possibility of becoming distracted from the pressing problem.”.

Several studies found an increase in brain activity, showed a spike in “functional connectivity” between the lateral prefrontal cortex and other parts of the brain in depressed patients, with more severe depressions leading to more prefrontal activity.  The belief is that rumination occurs due to the hyperactive VLPFC.  Andrews and Thomson argue that this relentless fixation also explains the cognitive deficits of depressed subjects, as they are too busy thinking about their real-life problems to bother with an artificial lab exercise. 

The activity in the VLPFC not only may lead to the tendency to ruminate, but also leads to a particular style of thinking:  analytical. Rumination is rooted in the working memory, which allows us to work with  all the information stuck in consciousness. Lehrer explains that, “When people rely on working memory — and it doesn’t matter if they’re doing long division or contemplating a relationship gone wrong — they tend to think in a more deliberate fashion, breaking down their complex problems into their simpler parts."

Depression Used To Boost Brain Power?

Andrews and Thomson see depression as a means to boost weak analytical skills.  Andrews and Thomson say that depression may exist “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.”   

There are many that view this theory as not taking into account all the variables relating to depression. Peter Kramer, a professor of psychiatry and human behavior at Brown University, describes the paper as “a ladder with a series of weak rungs.” Kramer, author of “Listening to Prozac,” advocates the importance and effectiveness of anti-depressants.  Kramer criticized the work of Andrews and Thompson.  “This study says nothing about chronic depression and the sort of self-hating, paralyzing, hopeless, circular rumination it inspires,” Kramer wrote. And what about post-stroke depression? Late-life depression? Extreme depressive condition? Kramer argues that there’s a clear category difference between a healthy response to social stressors and the response of people with depressive disorder. “Depression is not really like sadness,” Kramer has written. “It’s more an oppressive flattening of feeling.”

Ed Hagen, an anthropologist at Washington State University who is collaborating on a book with Andrews says, “While the analytic-rumination hypothesis has persuaded him that some depressive symptoms might improve problem-solving skills, he remains unconvinced that it is a sufficient explanation for depression. “Individuals with major depression often don’t groom, bathe and sometimes don’t even use the toilet,” Hagen says. They also significantly “reduce investment in child care,” which could have detrimental effects on the survival of offspring. The steep fitness costs of these behaviors, Hagen says, would not be offset by “more uninterrupted time to think.”

Other scientists, including Randolph Nesse at the University of Michigan, believe complex psychiatric disorders, including depression rarely have simple evolutionary explanations.  Although Nesse says he admires the analytic-rumination hypothesis, he adds that it fails to capture the heterogeneity of depressive disorder.

Andrews and Thomson acknowledge that depression is a complex disorder with a wide array of symptoms. “To say that depression can be useful doesn’t mean it’s always going to be useful,” Thomson says. “Sometimes, the symptoms can spiral out of control. The problem, though, is that as a society, we’ve come to see depression as something that must always be avoided or medicated away. We’ve been so eager to remove the stigma from depression that we’ve ended up stigmatizing sadness.”  Andrews and Thompson continue to explore evolution theory as a way to understand and find treatment for depression.  With the continuing increase of people reporting depressive symptoms, it is vital to continue to explore etiology, symptoms and potential treatments. 

- Kim B.

Lehrer, J. (2010, February 27). Depression’s Upside. Retrieved January 26, 2015, from http://www.nytimes.com/2010/02/28/magazine/28depression-t.html?pagewanted=all&_r=2&