Depression as a pro-survival adaptation that solves hard problems

In Scientific American, Paul W. Andrews and J. Anderson Thomson, Jr. sum up a paper they've recently published in Psychological Review that argues for depression as a pro-survival adaptation that allows for a kind of intense, isolated problem-solving introspection that, when combined with analytical techniques similar to Cognitive Behavioural Therapy, resolves complex troubles:
Analysis requires a lot of uninterrupted thought, and depression coordinates many changes in the body to help people analyze their problems without getting distracted. In a region of the brain known as the ventrolateral prefrontal cortex (VLPFC), neurons must fire continuously for people to avoid being distracted. But this is very energetically demanding for VLPFC neurons, just as a car's engine eats up fuel when going up a mountain road. Moreover, continuous firing can cause neurons to break down, just as the car's engine is more likely to break down when stressed. Studies of depression in rats show that the 5HT1A receptor is involved in supplying neurons with the fuel they need to fire, as well as preventing them from breaking down. These important processes allow depressive rumination to continue uninterrupted with minimal neuronal damage, which may explain why the 5HT1A receptor is so evolutionarily important.

Many other symptoms of depression make sense in light of the idea that analysis must be uninterrupted. The desire for social isolation, for instance, helps the depressed person avoid situations that would require thinking about other things. Similarly, the inability to derive pleasure from sex or other activities prevents the depressed person from engaging in activities that could distract him or her from the problem. Even the loss of appetite often seen in depression could be viewed as promoting analysis because chewing and other oral activity interferes with the brain's ability to process information.

But is there any evidence that depression is useful in analyzing complex problems? For one thing, if depressive rumination were harmful, as most clinicians and researchers assume, then bouts of depression should be slower to resolve when people are given interventions that encourage rumination, such as having them write about their strongest thoughts and feelings. However, the opposite appears to be true. Several studies have found that expressive writing promotes quicker resolution of depression, and they suggest that this is because depressed people gain insight into their problems.

Depression's Evolutionary Roots (via Neatorama)


  1. Interesting, but I don’t agree with their last take on rumination. I doubt clinicians would think writing troubles down is a bad thing. In fact, coherently writing down fears and troubles can lead to ways to make changes. Rumination is the constant rehashing of problems without fixing them. The only way that I can think that writing down problems would be harmful is if you forced the person to write down the same things every time, whether or not they were resolved. THIS would be rumination.

  2. Unfortunately, common depression isn’t the realm of people that are introspective and write beautiful music, compose poems, or pine away for ideas for latest novels.

    Mostly they collect cats, and stink a great deal.

  3. Yeah, I’m not so sure about this whole rumination thing. I’ve had depression for nine years. Does any obsessive thinking I do result in solving of problems? Sure, sometimes. But I feel like the depressed person more often has the type of thoughts that do things like snowball into more distressing thoughts. There’s definitely an introspective part to depression, but the majority of thinking I do when I’m feeling depressed is the kind that’s more harmful, frantic, panicky, and emotion-driven than analytical.

    1. the majority of thinking I do when I’m feeling depressed is the kind that’s more harmful, frantic, panicky, and emotion-driven than analytical.

      That may have to do with the fact that we now routinely refer to anxiety as anxiety-depression or just depression. Probably because anti-depressants are easier to prescribe (albeit incorrectly) and have a higher profit margin than anxiolytics.

  4. I’ve always thought depression was an evolutionary DISadvantage.
    Its commonly known that a number of depressed individuals choose to self-terminate. They could be trying to avoid passing along faulty depression-riddled DNA.
    Low sex drive could be another way to prevent the depressed person from passing on the faulty DNA. Same could go for the desire to be alone.
    The lack of or loss of interest in activities that used to be enjoyable, well that’s just icing on the black cupcakes of depression; further pushing the depressed individual down the path of isolation and possibly self-termination.
    Having suffered from depression for the past 15 years, I feel I can safely say there is NO advantage to depression (evolutionary or otherwise)–at least not my personal flavor of depression.
    I bet subsequent comments will back me up on this at least: modern science and medicine don’t know crap about depression.

  5. the article is interesting but entirely speculative. The authors assume that depression must have some indirect or long-term benefit on the sufferer, however they do not explain why this must be so.

    Here is another equally plausible speculation, that assumes the opposite.

    “Humans have a handful of genes that control mood, personality traits, and people who inherit some combinations of these genes are predisposed to be creative intellectually, to do well, prosper, have a big family, etc. but other combinations of the same genes predispose the people who carry them to depression – the net benefit on the genes, through the people who get the right sets of genes more than compensates for those who get the ‘bad’ sets. and so the negative conditions – depression – schizophrenia – etc. – are never bred out.”

  6. I’d be more likely to visualize the various grades of Autism and Asperger’s Syndrome as survival adaptations for antisocial couples and/or small bands separating themselves from a larger, more complex society that’s, say, in the grip of an epidemic.

  7. @ #4

    That’s because depression and anxiety are comorbid – around the 80% mark. Personally I would much rather have an antidepressant than an anxiolytic prescription. Anxiolytics make good crutches, but relapse rates are very high when people stop taking them (around 75% in the first year). Cognitive-behavioural therapy is incredibly effective for the treatment of anxiety, and some studies have shown anxiolytic medications may attenuate the effects of therapy, with those receiving therapy alone having better outcomes than those with both therapy and anxiolytics. I’d love to have doctors cut back substantially on axiolytic prescriptions, and also not doling out antidepressants like candy (I know this is only some doctors, many are very good).

  8. maybe it’s simply that depression fulfilled an evolutionary role in pre-civilized times, and some disconnect in modern life has turned it into a liability rather than an asset? it’s really, really hard to believe that a personality trait as pervasive as depression would have survived for so many millennia without having some critical, important purpose to it. i also wonder if it’s a dietary, gluten-influenced thing…

  9. Thought processes during bouts of depression seem to be (to me at least) less clear and less likely to resolve problems.

    But it may be that depressive thought is better than no thought at all, but that it’s usefullness has been surpassed by a superior strategy, namely culture placing value on thought for it’s own sake and providing for people who think for a living.

  10. @MisterJuju – an interesting thought, but you’re essentially talking about group selection. i.e. there would be no evolutionary advantage to the individual in not passing on his/her DNA, only to the group, and as we all know (?) group selection is an illusion. Or at least that’s what Richard Dawkins says. I have my doubts, based on a very low level of knowledge about the topic, but boning up on this is on my “to do” list.

  11. I’m going to start out by saying that I found the article more illuminating and useful than most things I have read on the subject of depression.

    It’s important to note that there is a significant, if often overlooked difference between clinical and situational depression, and this article seems to be in reference to the latter. (It would probably help if the author made this more clear.) Obviously, the concept of rumination does not apply to depression where there is no external cause to ruminate on. Post-surgical depression is an example that springs to mind.

    If for a moment we accept what the article says as being plausible, part of the problem of depression in in modern life could be that the depressed person is not able to take the time and mental space to ruminate a problem to its resolution. So much of our work is intensely analytical, using the same mental muscles that, according to this article, might otherwise be working out the problems that spark depression. It’s not much of a stretch to see how this conflict could lead to anxiety, and in turn squirrel caging*;
    -Take two opposing and urgent needs,
    -mix in some guilt for following one above the other,
    -throw in some willpower to keep pulling you back to a task, and trying to quash the rumination
    -pepper on some (by this time, welcome) distraction like computer games, TV, or interesting blogs
    -and allow to stew with a few healthy failures resulting from an inability to focus on one’s work, a lack of confidence, etc, etc
    … and you’ve got a nice recipe for making a much bigger problem than you started out with.

    I’ll give this one a “plausible.”

    It occurred to me, after reading this article, that my ongoing battle with what seems to be situational depression made habit began not long after I gave up writing (as I thought at the time) stupid stories for my own pleasure. There were other factors that would have kicked it off as well, but I’m beginning to wonder if the “made habit” part of my problem could have come from not having my old release valve.

    Will have to investigate this idea further.

    *squirrel caging refers to thoughts that rattle around in one’s head without going anywhere, much like a squirrel trapped in a hamster wheel. Stolen from an article on Douglas Repetto.

  12. The article seems interesting.

    I think the idea is not that depression itself is useful, but that depression is a side effect of a useful brain-adaptation for introspection. A bit like how autism is possibly a side effect of our ability to think abstractly.

    Being able to shut the world out and concentrate is obviously very useful for some problems. Perhaps depression is a result of super-expression of this ability. Depressives may get stuck in a negative feedback loop as their brain tryies to ‘solve’ the problem by getting progressively more introspective and withdrawn. The ‘introspection’ adaptation can start getting harmful, because extreme introspection stops helping analytical problem solving.

    For me, the best way to get out of a depression is to try and get distracted by the real world – or to force myself (or get forced by ‘events’) to do something practical about my problems rather than just introspectively thinking about them in the hope that a theoretical solution will present itself. Usually, I soon realise that my depressive thoughts were a pessimistic parody of reality and that ‘breaks the cycle’ of my depression.

    Obviously, different types of depression are different (I don’t suffer from severe depression and don’t take/require any medication) so this won’t be some silver bullet theory that explains all depression. It’s an interesting hypothesis though.

  13. I disagree: depression is a debilitating condition that drives one to self destruction. When its merely mild, it stunts creativity. When it is severe, you just want to die.

  14. Even if the hypothesis is true, the fact that depression conveyed an evolutionary advantage to some people some of the time (or even just a few people) does not necessarily mean it is useful to all (or even most) of people who have it.

  15. I thought there was a clearly demonstrated genetic component to depression. The Pennsylvania Dutch f’rinstance.

  16. Depression may have had an evolutionary advantage early on, but now it’s like an autoimmune disease. It makes you weak, it sickens you, then, if uncontrolled, it kills you.

    I’ve been struggling with it for over thirty years (cognitive-behavioral therapy, no meds). I have to fight it every damn day. Rumination is not my friend, it’s my #1 enemy–the feedback loop from hell.

  17. modern society prefers frictionless psychologies, depressions ‘effects’ are heavily influenced by it being seen as abnormal: abnormal by what standard? schizophrenia, depression, bipolar are all states on mind that have no comfortable place in within society; the medication used to treat are primarily for removing objective symptons, those symptoms that cause friction with the societal norm. subjectively the medication just replaces one set of symptoms with another, they do not cure. rationally a cure can only come from within and includes acceptance of ones state as such and each instance will only be understandable to the subject: there are no external correlations.
    cognitive therapy helps.

  18. I was continually depressed from around 10 years old (perhaps earlier) all the way through my teens and into much of my twenties. The issue in my life that depressed me the most is still something I haven’t dealt with. I’ve merely come to terms with it.

  19. i believe it does help you solve things, i wouldnt be nearly as good at solving problems and or seeing things as they really are had i not looked at them through the eyes of depression i think it makes you more in touch with reality and helps you know who you really are.

  20. I have to wonder if the author has ever actually BEEN depressed—the heavy-duty, clinical depression that makes it an effort to eat, to stand up, to breathe…I have, and I can say definitively that my problem-solving was not improved; it pretty much took a hike for the duration. It took all my brainpower just to stay alive and keep functioning in a rudimentary way, while my thoughts scurried around in circles like a rat with it’s tail in a trap. After a time, I completely overlooked possible ways of coming out of it—didn’t even think about going to the doctor any more. Fortunately, it eventually dissipated on it’s own, about 8 months after the triggering stimuli were no longer there.

    Might work with very mild depression, for people who normally are not introspective in the first place, just by forcing them to slow down…but in general, I don’t think this is a silver lining that could be relied upon.

  21. It’s very easy to construct an evolutionary argument for just about anything when you use a shallow understanding of the phenomenon, coupled with a careful choice of words. For instance “rumination” sounds pleasant enough, something that deep thinkers do, possibly even something particularly *good*, while “obsession”, which isn’t much different from rumination, really, carries a negative connotation, implying a less good, or less healthy behavior. It’s much harder to argue the evolutionary benefits of obsession (though I’m sure it could be argued).

    But placing that aside, the assumption that depression primarily involves rumination, and not a complex suite of fluctuating symptoms, reduces the object of study down to a single feature that — as anyone who’s suffered depression knows — doesn’t really represent the experience and effects of depression. It’s as if the authors watched a bunch of Cymbalta commercial and felt compeled to provide an evolutionary explanation for why that lady won’t get out of bed.

    Finally, there’s a lot of research in education, psychology, and and anthropology (including evolutionary anthropology) that shows problem solving is vastly enhanced by *collaboration*, not isolation. Maybe depression as problem solving mechanism evolved pre-language, however if that’s the case it’s survived past its usefulness, since talking things through, in the vast majority of cases, is more useful than the Hollywood-propagated lonely genius style of problem solving, which most of us are terrible at.

    A lot of faulty logic and uncheckd assumption goes into many evolutionary arguments.


  22. This is a very interesting topic for me. I don’t mean this to sound bad or anything but I can’t for the life of me comprehend what having depression is like. I mean, don’t get me wrong: I’ve been depressed, everyone has, life is like that. But it’s always been centered around an issue – all I have to do is resolve that issue and it goes away.

    Is having depression not like that? I kindof don’t quite understand why so many people are depressed. It seems to be almost a “common” condition – we all know at least one or more people who are depressed, right?

    And lastly, I’ve also noticed another interesting thing (this is purely an unscientific opinion so please don’t get mad) – I have a lot of friends and family scattered around the world (Europe and Asia mostly) who I stay in touch with frequently – I have observed that depression doesn’t come up at all when I talk to them but it certainly is a topic of conversation with my American friends. I’ve often wondered why this is: is it because American culture encourages talking about it more openly or is it because there is less depression in other cultures?

    Sorry, for the long post, as I said, this topic is fascinating to me. Hope I haven’t offended anyone.

  23. A number of people seem to think (including the author) that because depression is not a highly effective way to deal with problems that it could not have developed for this purpose.

    Since evolution is based on the proliferation of the highest RELATIVE effectiveness, an adaptation need not be HIGHLY effective to be favored. Only MORE effective.

    It’s not at all surprising that we can come up with more effective problem solving techniques using some understanding of human psychology and experimental data. This does not in any way refute the hypothesis that depression is a natural adaptation used for solving problems.

  24. I agree with the premise of the article, but recognize that my experience is anecdote, not data.

    But yeah, 10 years of depression –> figuring it out, and it was worth every single miserable lonely second.

  25. Wait, so this is the argument: being in a state of depression is an adaptive tool we use to understand our problems and self-actualize? And then we can not be depressed?

    I think what the researchers are talking about is a kind of “sadness,” or even “extended sadness” or “intense sadness.” I would agree that sadness helps us to understand in a similar manner in which the research describes depression.

  26. I suffered from depression for 20 years (and still do in a manageable-ish form). The important word there is ‘suffer'(ed). In this time I’ve met and talked to dozens of other people in similar situations. Some have been unable to cope and killed themselves. One jumped in front of a bus and is now severely mentally and physically disabled – a vegetable. The idea that depression is an ‘advantage’ in any way at all is frankly laughable. As for deep rumination, yes it happens, and most of it consists of reinforcing self-loathing. Also, most poets, comedians, writers and other creative types are bipolar and create during the ‘up’ stage of their conditions.

  27. Having struggled with major unipolar depression for more than 25 years now, I disagree with their contention based on personal experience. When deeply depressed, you’re not able to engage in “uninterrupted thought” — your thoughts are uninterrupted, but they’re uninterrupted as they go in a tight circle of “I’m a failure, I suck, I can’t do anything right, I’m a waste of oxygen, the people who love me would be better off if I were dead, I’m a failure…”

    Also, other research has shown that depressed people’s cognitive ability is decreased, not increased. Studies cited in Peter Kramer’s book Against Depression showed that depressed patients were significantly worse than non-depressed people at simple exercises “like a child’s dot-to-dot game”:

    The task is not one that depressed patients do well. Even worse than the initial error rate is depressives’ response to correction. In the test, if a subject makes an error, the administrator gently points out the problem and suggests how to proceed. After correction, virtually no control subjects make a subsequent (“perseverative”) error. But depressed patients do—many more than controls even when the baseline error rate is taken into account. Some depressives have catastrophic reactions; after a correction, they go on to connect dot to dot in random fashion, as if they had lost all hope of succeeding at the task.…
    This result—perseverative errors—is interesting in light of the common claim that depressives are realists. It is true that the adaptive state for human beings involves a degree of unrealistic optimism. In gambling experiments, where subjects are asked to evaluate the odds of winning at a given level of risk, the nondepressed tend to give optimistic estimates, even in the face of mounting losses. The depressed are more accurate—well, what else would they be? But in these same trials, depressives continue to make bad bets. Even when depressives perceive accurately, they lack the motivation to heed their own judgment and alter their behavior.
    In interviews with depressives, including those in remission, Krishnan found that a similar problem explained the performance on the trail-making test. The depressives understood the correction but paid more attention to self-fulfilling prophecies—that they were fated to fail anyway, that they were screwups.

    I would be interested in knowing what, if any, personal experience with depression the authors of the original article have. (My guess: none.)

  28. The article is not about Clinical Depression. It’s about plain old, garden variety non-lethal depression. You know that funk you went into for 3-6 months after the first person you ever really loved dumped you? Or for a couple of weeks when you didn’t get that scholarship, or job or book deal? It’s _THAT_ kind of depression.

    Little d – depression is normal, big D Depression is not. It is a pathology with no evolutionary advantage. However, some believe that it may survive by following other traits with tremendous advantages in modern and even tribal societies ( Intellect, charisma, artistic ability ).

    Little d depression could easily have some evolutionary advantage in any social animal. Increased self awareness through increased introspection can easily seen as tremendously valuable in any complex social order. To see another clearly, you must first know your self.

    Like almost every other trait, excessive expression becomes destructive. That does not mean that the premise is without merit. Appropriate expression can offer insights that allow the sufferer to avoid the causes of pain in the future, and perhaps help head off other more directly destructive traits and tendencies.

    You could, of course paint it another way. That big or little d depression is simply the over-expression of the evolutionarily advantageous traits of intellect, empathy and critical thinking.

    The article doesn’t necessarily rule that out, it simply points out that this is one possible explanation for a trait that many see as having no value to the species.

  29. I get that the summary doesn’t do the article justice, but I can’t resist this: “depression as a pro-survival adaptation that allows for … introspection that, when combined with analytical techniques similar to Cognitive Behavioural Therapy, resolves complex troubles.”

    Sorry what? Depression was adaptive back when cavemen had CBT?

    I have to say I was inclined to introspection, ruminating, and social isolation years before I ever *felt* depressed.

    Nidsquid & others who haven’t been long- depressed: thanks for your puzzlement. It’s interestingly strange from the opposite POV. At least none of you repeated the classics: “Why don’t you A) lighten up B) go have some fun C) get off your butt and make something of your life!?” Yes, it’s different from being laid low by a problem and then working your way out of it. Roughly: deeper problems, failed safety- valves, & self-perpetuating reactions.

    Btw I don’t wish anyone would fall into such a pit just so they would understand what it’s like. And if you do fall in, I testify you did not invent it and there are step- by- step ways out, ask someone to help you find a couple: SSRIs (cheap now), CBT (doesn’t take long to learn), mutual- support groups.

    Not to beat a by-now dead horse, but there is such a thing as uninterrupted thought that consists of end- to- end unfinished, inconclusive, unhelpful thoughts, sort of like the paragraphs of this comment of my own here.

  30. Okay I read the Scientific American article (not the one in Psychological Review) and it’s pretty bad in parts.

    The good part: it’s plausible that there are adaptations to help us focus on problems, that sometimes that state amounts to depression, that often depression is useful problem solving, that the same adaptations lead into pathological depression, that changed behaviors adapted to promote concentration match up with symptoms of depression, and that VLPFC neurons and 5HT1A receptors have interesting roles in depression.

    Bad things about the article:

    It doesn’t distinguish short-term from long-term depression; it’s written as if long-term depression weren’t common.

    “…If depressive rumination were harmful, as most clinicians and researchers assume.” Assuming is not necessary when faced with a chronically depressed person.

    It talks about “interventions that encourage rumination, such as having them write about their strongest thoughts and feelings,” when more likely these interventions have the effect of resolving and stopping ruminations, and so the fact that they relieve depression counts against the authors’ thesis.

    Finally it recommends therapists encourage their depressed clients to ruminate, which is incredibly reckless, and hopefully any therapist who can open his eyelids far enough to read their recommendation realizes it.

    I think they make the “every trait is an adaptation” mistake, and also label the trait “depression” instead of something like “sustained thought about problem situations.”

  31. I think it is awesome to read this thread and see how many people are adamantly rejecting the ideas in the article. Why the awesome? Any paradigm shift is often met with criticism, and as progressive as your BoingBoing reader may be, this phenomena holds true. Awesome: you people aren’t robots from the future, just normal people with hang-ups. Folks, don’t be attached to your desire for a clinical malady. People will label you for something besides depressed if the idea of depression as a bad thing goes away; don’t worry, you will still find a way to be socially side-lined.

    I am a programmer/scientist/artist and often find myself in a long arc of productivity that separates me from friends and loved ones while I carve out the next opus. The reaction to this behavior is to label me as depressed… thing is, I’m not. I live a life filled with joy. The concept of the pro-evolutionary nature of depression fits. Its that right kind of “well… duh” psychology that makes you think it will stick. Great theory. Love it.

    Maybe emotional happiness is a bad choice for a personal teleology, eh? Now,

    quit your happy and get something done.

  32. Anonymous @37:
    “Folks, don’t be attached to your desire for a clinical malady.”…”don’t worry, you will still find a way to be socially side-lined.”

    Right. Nice troll. Because people with long-term clinical depression oh-so desire to have a malady. This isn’t a case of rejecting a new concept. People are criticizing a theory (with no real root in fact) that makes no distinction between ‘sadness’ and true depression. Read up on clinical depression. Hell, even read wikipedia. Shouldn’t you be too busy working on your next ‘opus’ to comment here anyway? Maybe you are just kidding and all of it went over my head.

    @26 Nidsquid: Appreciate the sensitivity in the questions, and well-asked. Often little distinction is made between the colloquial depression and clinical depression. The clinical variety is caused by chemical imbalances in the brain and is an illness. Medication is used to treat the chemical imbalance. This article seems to be talking about the universal experience being sad or in a funk, like after a breakup or job loss, like another poster commented. As for the cultural angle: interesting, and I’m sure there’s been a lot of research. Often in N. America physicians overprescribe antidepressants, specifically in non-clinical depressive cases. Perhaps there is a disparity in treatment and social acceptance, but I have no idea.

  33. @sworm: Yeeeah, what with all the extra energy it gives you, depression is clearly an adaptation designed to make people gravitate toward giving birth to and then taking care of children for eighteen years. Or, huh, I wonder, could you just mean that you like to take advantage of women whose defenses against douches are low? If that’s what you mean, I wish you’d just say so. To our faces. So we can walk away and hide in our houses contemplating the disgustingness of human nature some more, which frankly sounds like a lot more fun than talking to you (much less anything else).

Comments are closed.