In Brief
- The brain’s ability to enter a depressed state has been preserved throughout evolution, suggesting that depression is an adaptation.
- Depression promotes focused rumination about problems. People in this state of mind are better at solving complex social dilemmas.
- Effective therapies encourage patients to engage in rumination, allowing them to find solutions to their problems and end their depressive episode.
Why do so many people suffer from depression? Research in the U.S. and other countries estimates that between 30 to 50 percent of people have met current psychiatric diagnostic criteria for major depressive disorder sometime in their lives. This staggeringly high prevalence—compared with other mental disorders that affect only around 1 to 2 percent of the population, such as schizophrenia and obsessive-compulsive disorder—seems to pose an evolutionary paradox. The brain plays crucial roles in promoting survival and reproduction, so the pressures of evolution should have left our brains resistant to such high rates of malfunction. Mental disorders are generally rare—why isn’t depression?
This paradox could be resolved if depression were a problem of growing old or a result of our modern lifestyles. Aging cannot explain depression, however, because people are most likely to experience their first bout in adolescence and young adulthood. So perhaps depression is like obesity—a problem that arises because modern conditions are so different from those in which our ancestors lived. But this explanation is not satisfactory, either. The symptoms of depression have been found in every culture that has been carefully examined, including societies such as the Ache of Paraguay and the !Kung of southern Africa—societies in which people are thought to live in environments similar to those that prevailed in our evolutionary past.
This article was originally published with the title Depression's Evolutionary Roots.
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22 Comments
Add CommentWow, this article is totally spot on. Everything seems to make so much more sense when analyzed from an evolutionary perspective. I bet that the stronger your bonds tend to be with people and the higher you value them corresponds to more depressive episodes. (Do more intense, emotionally driven people get it more? It seems like they would because they are less likely to brush off social conflicts and are more acutely affected by them. I used to be like this but am not anymore. I also used to be deeply depressed but am not now.)
Reply | Report Abuse | Link to thisQuestion: how many engineering students compared to say, english majors tend to have depressive episodes? I ask because it seems like my whole department has emotional issues ;)
While I have not read the entire article, the engagement in rumination, mentioned, which is a natural tendency, as well, can suggest resolution through inappropriate methods.
Reply | Report Abuse | Link to thisWe have often encountered this, personally, in the news, and in the eager embrasure of prefabricated systems of belief, themselves less than appropriate for easing development.
Seeking resolution through the use of drugs (which have great effect on neurotransmission and modulation, and on our capacities to produce our own) is popular in most cultures, especially ours, with self-medication and prescription creating a vast spectrum of ways inhibiting the necessary self-discovery.
To milfy, above: I have found that engineers & students in related areas can have insufficient emotional connections with life, having a belief system rejecting relationships which we may have evolved to value.
This is not to say that emotional or existential issues are not shared by other college majors!
Consider going outside now and then, with purpose. The proper place to engage in ruminations just might be there, in sensory contact with the sky, earth, and diverse life. Ancient societies consistently taught the gentle discipline of solitude.
By the time of careful examination, the !Kung had been in transition for a couple generations, having lost their traditional freedom, habitat, and ways. Most anthropological studies in the past 40 years have mentioned their depression, loss, and change into a group of disadvantaged within the sedentary cultures now extant in their former land.
Reply | Report Abuse | Link to thisWhile not being familiar with the Ache, I do tend to suspect that the face of what is now Paraguay was heavily changed in the 20th century.
We ignore also the terrible effects of the takeover in North America of relatively environmentally-attuned cultures, of which modern descendants attempt to deal with a most severe depression and loss.
I certainly hope that this article wasn't an attempt at helping the educated moneyed class feel good about what they do through their systems to the rest of the world. Depression is often a response to the paralyzing inability to escape painful situations. Looking for a genetic code for rumination and calling rumination depression is very deceptive. I know people who are clinically depressed and I can assure you, they don't ruminate. They vegetate.
Reply | Report Abuse | Link to thisI found the article interesting, but I believe the authors might be misleading or misinterpreting to some extent. Where I agree that CBT as a whole is focused at reducing or eliminating ruminations, it leads one to believe they include Cognitive Therapy (as developed by Aaron Beck, M.D., at the University of Pennsylvania) as well. Cognitive therapy is focused at reducing the language of the ruminations surfacing so that the patient is not negatively impacted by the verbal messages that might flow from ruminations, ofter referred to as self-talk. Beck based this on common thinking errors that allow such surfacing. Research proves that this is more effective than other forms of therapy for depression and much more and more effective when other forms of therapy are combined with drugs. Since I have been there and back and studied it extensively, I can tell you it works and quickly. Am I cured? Depression is something you truly have for your life unless it is a transient sadness, but symptomatic relief is possible and likely if cognitive therapy is use correctly.
Reply | Report Abuse | Link to thisI thought the article was very interesting and am going to look for the full version in Psychological Review. I am especially interested in the last paragraph, which mentions new therapies that actually encourage exploration of depressive ruminations as a tool for healing and growth. I think many of the negative responses to the article, like many reactions to critiques of mainstream definitions of mental health in general, are driven by other, often personal, motivations, for example:
Reply | Report Abuse | Link to this1) sunk-cost consciousness: the disinclination to accept that one's efforts up to now have not been fruitful, but to change course implies accepting their uselessness
2) fear of social marginality: most people feel safer with the herd, i.e. accepting what medical doctors and/or Big Pharma say about mental illness. This vulnerability may be especially pronounced in people with psychiatric disabilities, since they are by definition more vulnerable to the stigma of "madness" (as well as formal and informal [social and otherwise] sanctions against those who don't "follow doctor's order")
I could go on but those are the main two off the top of my head. In response to some previous posters:
Deb--are these people you know on psychotropic drugs? Is it possible that the reason they seem to vegetate alone is that the "medicines" they're taking disable their ruminative capabilities? Or, is it possible that they are ruminating, but they've learned to hide the fact so well (because of how others tend to react) that they truly don't seem to be doing so, or maybe have learned even to hide it from themselves? (Semi-rhetorical questions I know.)
validjim--How can you differentiate between CBT and cognitive therapy? Cognitive therapy is just the 'C' part of CBT isn't it?
To me at least, when talking about CBT, that is the Albert Ellis school of thought. Beck's work was very different in that the underlying issues are not of a great concern. There is no reason for blame, but rather to change the way one listens to the underlying ruminations. By truncating the "automatic thoughts" or self-talk, relief follows very quickly. In fact, one of the reasons postulated for more 'professionals' not adopting cognitive therapy is the rapid relief and not enough patient time to be derived (now that is kind of a negative pattern, but we all know that some are that way). Read up on Beck or the more popularized version "Feeling Good" by David Burns, MD.
Reply | Report Abuse | Link to thisThe "depression" that these researchers seem to be referring to I think is actually a grief response to a difficult problem or disturbing event. A grief response will cause rumination and depressive symptoms; however, it is NOT the same as depression. A clinical depressive episode will consist of non-helpful rumination on paranoid ideas, self-hatred, or anger among other things. Cognitive therapy CAN be helpful in that it points out that these thoughts are not true!
Reply | Report Abuse | Link to thisHow can I state this so emphatically?
I have bipolar II disorder and have never had helpful ruminations from my depression. However, my son died in 2004, and the grief I felt was devastating, but not the same. I was able eventually to take positive steps to reduce my grief. Even on psychiatric medication, I grieved very much and came to terms with it.
Please don't start carelessly start another trend of "depression is not an illness" fad. Those of us who live in misery and are scorned by our fellow humans for being weak will not appreciate it.
You mean I'm not crazy?
Reply | Report Abuse | Link to thisYou mean I am not crazy!!??
Reply | Report Abuse | Link to thisHey this is a great article
Reply | Report Abuse | Link to thisI think the article makes sense to me. I don’t think the author is saying that depression does not
Reply | Report Abuse | Link to thisexist but that most people that are worrying about their rumination should embrace it as a positive
thing to help solve their complicated personal & social problems. The world is full of more &
more people taking anti-depressants & statistically they can’t all be sick or it would be an
epidemic & possibly contagious.
I felt relieved after reading the full article as I too have very complicated issues that I am trying to solve
& “thinking” upon them is a logical solution & well within my reach to solve.
I have been doing this for 25 years & solved some interesting problems & someday hope to publish them.
Clinical depression is a mental illness and is a biologcial disorder. It is not the same as feeling blue. It causes people severe suffering as well as memory problems, difficulty in all aspects of life and does nto go away. They need medicaiton and this medication has been shown to have scientific efficacy.
Reply | Report Abuse | Link to thisclincial depression is a biological disorder. It is not the same as feeling blue. People with clinical depression can have memory problems as well as other symptoms that severly interfere with their activites of daily living. The person with clinical depression does not have control over their depression. Medciation such as antideprressants have shown scientific efficacy in treating clinical depression.
Reply | Report Abuse | Link to thisThe person who said he or she values Cognitive Therapy, has studied it, and has seen articles saying it works is likely a victim of psychobabble, which is common in the field of psychology. If you train me to stop cogitating, you will then measure that as success (no cogitations or ruminations or depressing thoughts) and thereby conclude I am improved. This is a typical error in science. What if my SITUATION makes me cogitate? Then it is the situation not the mind that must be changed. That is where clinical psychology is a pseudoscience of no value to the suffering individual. We want less depressing situations - but of course being a psychologist, you measure my level of cogitation not whether my situation has improved. It is like the way the whole society has become this artificial environment based on the destruction of nature-based societies and species and nature itself. As long as you don't see it, you assume everything is okay. But it isn't. We are deluding ourselves. Similarly, to say CBT works because as a result of your therapy I am cogitating less is no different than saying you value my thinking less. My obsessive or depressive thinking might be an important reaction to the circumstances I find myself in. To say otherwise is to discount my experience, which is totalitarian. Can you help the tribes who have lost their land in Canada to tar sands feel less depressed by CBT? If so, what side of the fence do you end up with with your CBT? It is pseudoscience, and this article is saying depression is useful. While you are saying it is "pathological" and must be wiped out with your mind sterilization techniques.
Reply | Report Abuse | Link to thisThe main issue that I have with this article is its suggestion that depression is a built in adaption which offers some type of benefit. The article doesnt take into account that certain people and families are prone to depression. Is this article suggesting that only a certain strain of person with the depressive personality gets to benefit from this adaption whilst the rest of the population doesnt? (Depression frequency increases with episodes)
Reply | Report Abuse | Link to thisKenneth Kendler of the Virginia twin studies has found good evidence that neuroticism is a strong predictor of depression. A person that possesses this lifelong trait will be predisposed to dysfunctional behaviour which subsequently leads to depression. (If we are to believe the article, depression is an adaption which will then allow the individual to fix the problem that there personality created)
In my view it is more likely that depression in many cases is the result of a sensitive brain. The more sensitive an individual, the more pain they will feel for a given problem. Taking this into account I can see how a researcher could be fooled into thinking that depression is there for a reason and not just a by-product of a sensitive nature.
There are other issues to with depression such as evidence that has been accumulating suggesting that it is pathological to the brain. (Shrinking of the hippocampus, cell death and so on) Some adaption!
@milfy: the same is true for my chemical engineering department. people are definitely gloomier than average, certainly a lot gloomier than the arts students
Reply | Report Abuse | Link to this"Depression promotes focused rumination about problems. People in this state of mind are better at solving complex social dilemmas" I disagree. The rumination in depression, is irrational, morbid and can lead to suicidal ideation and attempts. Depression makes it almost impossible to make any decision. One is profoundly overwhelmed by catastrophie.
Reply | Report Abuse | Link to thisIt is difficult to understand why the clinical and scientific communities are still pondering the causes and effects of depression and in this absence of certainty entertain diverse opinions.
The assumption that severe, repetitive, clinical depression, is a response to environemnt, is questionable and can lead suferers into the wrong form of therapy. The the most likely cause is a bio-chemical disorder, that it is inherited, and is not likely to repond to a more uplifting environment or talking therapies. Many clinicians advise people in severe depression not to make big decisions because their judgement is impaired.
"Depression promotes focused rumination about problems. People in this state of mind are better at solving complex social dilemmas"
Reply | Report Abuse | Link to thisI cannot disagree more strongly. The rumination of depression is irrational, paranoid and morbid to the point of suicidal ideation and suicidal attempts. People with severe depression isolate and can become overwhelmed by social interaction, often to the point of becoming bed-bound. It is my experience that clinicians advise patients not to attempt making any important decisions in depression as judgement is impaired (least of all anything resembling complex social dilemmas).
It is a concern that some clinicians and researchers remain in the dark about this and look for some cause of 'severe, repetitive, clinical depression' other than a serious biochemical disorder.
Looking to make some connection with evolutionary survival/reproductive mechanisms might lead one to assume that the same could be said of diabetes etc. A person in severe clinical depression is profoundly sick and maladaptive.
It's an illness, not to be confused with those episodes of deep sadness and depression associated with loss or other calamity, previously diagnosed as 'reactive depression'. In these cases it may be some kind of natural response and one which can be treated with counselling thereapies. I doubt that such therapies are effective as the first line treatments for those with severe organic depression.
This whole thesis assumes depression is a response to an event or series of happenings that are profoundly distressing. This is probably true in certain types of depression. But it takes no account of depression that is recurrent and unrelated to life events. Endogenous depression very often manfests in late teens and early twenties. It can also be the onset of bi-polar disorder. To suggest that an illness of this gravity, that can lead to suicide at one poll and unihibited and dangerous behaviour at the other, is adaptive, is most likely to be misplaced. Such depression, whether uni-polar or bipolar, does not respond so well to psychological intervention and needs medication. This suggests that there is an organic dysfunction. Moreover, the fact that such illnesses tend to run in families, indicates that there is likely to be a genetic element.
Reply | Report Abuse | Link to thisIt is true that there is a depressive state that is triggered by a life event. This is most probably a grief state, reflective of loss, that heals in time without clinical or psycholigical intervention. But recurrent endogenous depression, that affects about 1% of the population, usually has its onset in late teens and early twenties and has little, if no connection to life events. It may also be a sympton of bi-polar disorder which is known to onset most frequently in the mid to late twenties. Rumination in this depressive state is invariably compounded by paranoia and agoraphobia and manifests itself in delusional, catastrophic thinking, distorting reality and often leading to suicidal ideation and attempts. The fact that such depression, whether on the spectrum of bi-polar or unipolar, often runs in familes, also suggests that there is a genetic factor. This is an organic dysfunction which almost always requires clinical intervention and medication, usually on a long term basis. This is a serious illness, disabling sufferers from engaging with life, relationships and holding down jobs as well as the high risk of suicide. The state of elation in bi-polar often embodies unrestrained spending, debt, inappropriate relationships and sex and delusions of grandeur and omnipotence. I am concerned that Scientific American has published an article so badly informed and seemingly based on mythology.
Reply | Report Abuse | Link to thisevolution spends hundreds of millions of centuries creating a species honed for survival, and one of the first things we learn is that death is inevitable. no wonder we're all a bit depressed ;)
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