Why is there depression (I mean from an evolutionary biology perspective)?

In other words, why would depression evolve?

My guess would be that it's a result of being a species whose evolution occurred during intermittent ice ages. You learn to shut down during the long cold winters so you don't freeze to death.

'Course this is probably me just being silly and you could just as easily argue that depression has to do with evolution only inasmuch as we evolved to be active hunter-gatherers and depression results (largely) from inactivity. (See, I just did.) Also, homo sapiens evolved in Africa, presumably largely shielded from the harsher effects of ice ages. I suppose though that if Caucasians and especially Nordic peoples have higher rates of depression, as I seem to recall, it might indicate that evolution continues to act upon us in slight and mostly annoying ways.

Anyway, does depression figure into questions of survival of the most fit? Or where in hell did all of us major depressives come from?

overwhelmed and not getting much out of the situation. That is when it isn't the result of major loss & grieving.

Different people can take different amounts of shit or stress or whatever.

If you don't pay attention to your feelings.. and change something.. you get more depressed.

"free". In every sense of the word.

At times there is only one form of escape. And who would champion that?

you. That at the start it is a sign to move on or up or out or make some changes. Thankfully there are great treatments these days if it goes too far.

But - if you are not taking care of yourself - you can get depressed. Lots of teen girls (and boys) go through it a bit. (or anyone facing adolescent attacks). Cause those years are so hard.. and it is easy to get caught up in the wrong group for you. Or no group. Or whatever. Easy too to be dehumanized by bias. So too abusive relationships where the depressee is not living robustly. A cure for depression is often to get out and do something you love.. or to volunteer or seek spiritual connection.

For parents of special needs kids..they have respite care.. cause they are at risk for depression. And they have clubs now for girls in teens - that focus on girl peers only instead of the mixed groups where girls can easily be attacked for either being 1) sexually active 2) not sexually active 3) perceived as sexually attractive 4) perceived as not sexually attractive. It is pretty easy to be attacked at a teen.. for simply being who you are.

Depression is with us because most people who suffer from it don't get really bad until sometime after reproductive age. In other words, it doesn't necessarily prevent reproductive success, so it isn't weeded out.

Don't know what the numbers are overall, though. An interesting idea, but I'm not sure it holds up. Thanks at least for addressing the question.

But the average sufferer probably doesn't suffer debilitating effects until well into the 20s (sometimes even later).

If you aren't a virgin, my point is made.

diagnosed until later. I believe I was depressed as a child, but in those days, I don't think anybody ever looked for in children.

I certainly hope that has changed.

The majority of human evolution occurred living in relatively small bands. One knew everyone. The group depended on one another. Everyone was valued by other members of the group. We could see the result of all of our work. We evolved to thrive mentally in these circumstances.
At least some depression results from individuals, who are more suited living under these circumstances, feeling alone and purposeless in the modern world.

but it doesn't exactly address the question, which is why would depression as a trait survive. I guess in a sense you are saying that it pushes us back to the group, except that isn't ever what happens. Mostly we just lie around saying, "Why bother? Who cares?" It still seems to me to make most sense as a kind of survival response to enforced winter cabin (or cave, or icehouse, or mammoth-bone house) fever. But an interesting approach, certainly.

People weren't meant to live this way. :shrug:

They called it melancholia, but the symptoms were the same.

When I had depression, I was given many definitions: learned helplessness, anger turned inward, whatever. People have felt helpless against their misfortunes or angry at people they couldn't afford to be angry with since the beginning of time.

I suppose a lot of today's depression is due to people being angry and frustrated and not knowing where to direct it.

It's because of a genetic disorder known as joblessness.

Seriously though, I think our brains are very complex, and it's very difficult to break down and come up with an explanation for a lot of things we feel. For example, why do we enjoy music? From an evolutionary perspective, I don't think that can be explained.

As others have said, depression warns you when you are in a non-functional situation, either in terms of relationships or clans or even physiological situations. Certain illnesses or conditions can bring on depression. High cholesterol, high blood pressure, diabetes, impending heart attack, even obesity can physically cause depression. People with these conditions will often feel suddenly depressed either just before they take a turn for the worse, or just before or after they eat something or do something which puts them at greater risk. Someone with high cholesterol, for instance, may feel a sudden depression just before washing a pizza done with a coke. Most people chalk this up to broken promises, or feelings of worthlessness or inadequacy, believing the depression is because they can't stick to their diet, but that's not it. The depression is the body warning them not to do what they are doing. People who do not even realize they have high cholesterol, for instance, will still feel this, even if they are not dieting.

Same is true of the emotional side. Humans are basically societal animals, and survive best in a herd. When you are doing something to risk losing your herd (family, friendship, romance, clan, etc), you become depressed. Your body warns you not to continue what you are doing, to try to bring back the positive feeling by undoing what you were doing. (Think natural selection--as humans survive best as a group, those without these physiological reactions are less likely to survive, etc).

You ask why depression just shuts you down, but that isn't it's only stage. It causes you to hesitate, to want to stop what you are doing, so that you will change your behavior (eating, loving, whatever). When ignored too long, depression discouragous you from continuing what you are doing, and eventually, tries to discourage you from doing anything at all, to keep from making it worse. Just as the urge to sleep can be fatal in freezing temperatures, though it is triggered by the bodily need to rest, depression can be triggered in situations where there is no real exit, and where depression is harmful instead of helpful. But that's when it goes too far. The biological response tries to create the change before you go too far.

That's my theory. Probably wrong, as always.

the rational behavior is to conserve your energy and not to try so hard - wait until something else changes that might make effort more worthwhile.

Seasonal Affective Disorder is our body telling us to slow down during long dark winters, conserve our energy, and wait for spring to start hunting and gathering.

the other way around. :shrug: I was so depressed I didn't want to move. Then I ended up with diabetes and other chronic illnesses that made the depression worse. The whole thing tends to end up in a downward spiral. The worse I felt, the more I ate, the less I exercised, which made me feel even worse. I'm still trying to find places to attack the cycle.

was that mild depression was actually a valuable personality trait in some cases - it causes people to more intently focus on performing a task rather than socializing with the group. Someone who was mildly depressed might more easily focus on making stone implements, sewing garments, etc., for hours on end. Having a few people like that in a group helped the group overall.

I am not endorsing the focus of the book and its acclimation for pharmaceuticals - just think that like sickle cell trait, a small dose of it may produce individuals who can play a valuable role in society, despite the negative consequences. This is a role that we no longer value, as we focus more on individual accomplishment rather then on small contributions to the group.

... which is a type of depression (triggered by lack of sunlight during the winter, especially at high latitudes). At least one researcher claims that it's related to other disorders. I seem to recall the researchers theorizing that it would encourage saving energy (and encouraging our early ancestors to mate in the spring). Someone else says that it's just because we aren't used to extreme seasonality yet (even though humans have lived in polar environments for thousands of years).


A couple of sample articles:

Title: Seasonality and seasonal affective disorder (SAD): An evolutionary viewpoint tied to energy conservation and reproductive cycles
Author(s): Davis C, Levitan RD
Source: JOURNAL OF AFFECTIVE DISORDERS 87 (1): 3-10 JUL 2005
Abstract: The characteristic symptoms of SAD, including hypersomnia and weight gain, might reflect a genetically programmed attempt to conserve energy during historically predictable periods of dwindling food supply. While this basic hypothesis has obvious conceptual appeal, few authors have considered the specific positive selection pressures that might have contributed to such a process. The goal of the current paper is to further develop an evolutionary model of SAD with a focus on energy conservation in the context of seasonal reproductive cycles. To accomplish this, seasonal data on birth rates are considered from an evolutionary viewpoint. There is considerable indirect evidence that in temperate climates, the symptoms of SAD reflect a predisposition for conception to occur in late spring/early summer to ensure a peak of births in the late winter/early spring. The adaptive value of such a pattern, and its putative role in natural selection in humans, is also discussed.


Title: The role of genetic factors in the etiology of seasonality and seasonal affective disorder: an evolutionary approach
Author(s): Sher L
Source: MEDICAL HYPOTHESES 54 (5): 704-707 MAY 2000
Abstract: The degree to which seasonal changes affect mood, energy, sleep, appetite, food preference, or the wish to socialize with other people has been called seasonality. Seasonal affective disorder (SAD), a condition where depressions in fall and winter alternate with non-depressed periods in spring and summer, is the most marked form of seasonality. Several lines of evidence suggest that genetic factors play an important role in the etiology of seasonality and SAD. Millions of years of evolution and adaptation have optimized human biochemical and physiological systems for function and survival under equatorial environmental conditions. Modern humans began their migration out of Africa only about 150 000 years ago. Little change in our 'equatorial' systems might have been expected over this relatively short evolutionary time-span. The author suggests that a genetic susceptibility to seasonal changes in mood and behavior is a genetic predisposition to an insufficient adaptation to temperate and high latitudes.


Title: Evolutionary Origin of Bipolar Disorder (EOBD) - Target article by Sherman on evolution-Bipolar-Disorder
Author(s): Sherman JA
Source: PSYCOLOQUY 12 (28): 1-24 2001
Abstract: The hypothesis of the evolutionary origin of Bipolar Disorder (EOBD) attempts to make sense of ED by placing it in evolutionary perspective. The hypothesis emerges from ideas about the importance of the organism's biological clock and energy-regulating mechanism (Wehr, Goodwin, Rosenthal), and theorising that ED descends from a pyknic (compact, cold-adapted) group (Kretschmer). It suggests that ED behaviors evolved as highly derived adaptations to the selective pressures of extreme climatic conditions (long, severe winters and short summers). The EOBD hypothesis integrates existing observations, economically explains puzzling aspects of ED, yields testable predictions, and suggests new research directions.

... and one I've considered many times. I have bipolar disorder (fortunately a minor case, but bad enough that I take meds). I spent my first 20 years of adulthood hypo-manic, with the attendant pluses and minuses.

Now that I understand the manifestations of the disorder, I realize that I've known several people with this condition throughout my career. While it has its bad side it has a good side also (hypo manic people get a LOT of shit done :))

I believe that this, as well as regular old depression, are merely extremes (edges of the bell curve) of normally occuring evolved characteristics. I believe that these conditions can be exascerbated in folks with a genetic predisposition by life events.

But most of all I do believe that depression and even bipolar disorder have their roots in "normal" evolved brain function that is there for a reason. Many here have already posited good theories for depression, i.e. - your mind warning you that you are not taking care of yourself.

...namely, the ability to form beliefs. It's an amazing and purely mental evolution, and helps cement our cultures together. It has some odd by-products such as religion, and can turn directly against oneself in various forms of mental illness, depression included.

Evolution is just the mechanism by which we have biodiversity. The fact that people can get depressed is one of those things that just is. It doesn't help or harm the species as a whole so it continues to just be.

Suicidal thoughts and all.

but if not, make sure that the most drastic action that you take is to call a qualified counselor, therapist, or psychiatrist, or at the very least a help line. Any positive step tends to help, so you may find that just making the call will make you feel better. At least that was always what happened with me. Regardless, hope you're feeling better soonest, and :hug: :grouphug: :thumbsup: to you

It's in the planning stages. No hope.

Remember only this: the least, remotest hope that someday life may be better is always better than extinguishing that hope forever. Today, this minute, do ANYTHING that has ever made you feel even slightly better, be it watching a silly comedy like Monty Python or Airplane, taking a walk, or calling friends or family. Then as soon as possible call a help line. Then schedule an appointment with a counselor or psychiatrist or priest or shaman or whatever you're comfortable with. Do not do anything drastic. It's just shit in your brain; trust me on this. Please.

There is a number you can call, hearing another voice: 1-800-784-2433. Hope might grow back, slowly first, but it might. The opportunities are here. Please.

that it helped a band of primates to have a couple who were always anxious and alert. It may have been tough to be the stressed out monkey, but the band as a whole thrived because someone was always looking out for the leopard while everyone else was playing. I think depression results when the person is so hyper-aware of everything going on that he/she can't ignore all the little bad things that happen. A reprimand that one person ignores sinks into the soul of a depressive and continues to cause pain.

I do not know why it does evolve. But I do know that some are out there trying to answer these questions.

Here's a phone number: 1-800-784-2433.

Please use it.

Call Me Wesley
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