Depression and evolution

[Undesired Walrus]

Does depression have any evolutionary advantage? I was just wondering why it persists in Humans, when it really destroys your desire to do anything, including reproduction.

[Dancing David]

There are many possible reasons that depressione xists in evolutionary terms with the huge caveat:
determinsim of traits (Gould's usage) is often an error in thinking, to say something exists because of evolution misses the point. There are many reasons for this.

Possible reasons that depression exists and has not beene eliminated through natural selection through reproductive success.
1. It is a side effect of the cyclical nature of human biology. In that it is a trait which is a bug in a system that is essential to human survival.
1.a. Same except for the precense of moods.
2. It is associated with traits that in partial expression are very beneficial to reproductive success. So while it may be detrimental to those who have a full trait, it may be beneficial to those witha partial trait.
3. As a stress related disorder that often manifests on a partial basis it may not be that detrimental to reproductive success.
4. As the flip side of mania and hypomania, it may be that those traits do get selected for and that this is just a consequence of that.
5. Depression does not always involve 'vegetative' symptoms, it can involve obsession with sex.

[MG1962]

Does depression have any evolutionary advantage? I was just wondering why it persists in Humans, when it really destroys your desire to do anything, including reproduction.

Well in humans a lot of traits that would have burned out, continue to manifest themselves because of the communal nature of us as animals. We seem willing to carry other members well beyond their time as a productive part of the community

We are virtually unique in being one of the few animals that will adopt and raise off spring we did not directly produce

[plumjam]

I think it's more a case of belief in evolution providing an advantage to depression.

[Symbol]

I was just wondering why it persists in Humans

We know it exists in humans, but could incidence not in fact be decreasing, even while our describing, measuring and recording of it is increasing?

We can't exactly compare current studies with data from 2000 years ago, 6000 years ago ...

[Olowkow]

Belief in gravity is very depressing as well.:D A real downer.

[BlackCat]

Does depression have any evolutionary advantage? I was just wondering why it persists in Humans, when it really destroys your desire to do anything, including reproduction.
Like a lot of things, not because it has an advantage has it survived, but likely because it's not enough of a disadvantage to interfere with reproduction.

Not all depression sufferers have the same degree of depression, either. Mild sufferers could easily still have children, and attempt to live a normal life.

[Dr. Imago]

I'd suggest that one has to think of the clinical manifestation of depression in relation to the external stimuli that evoke it. There may be a genetic propensity towards depression in certain individuals, but usually it is environmental factor(s)/pressure(s) that cause it to rear its ugly head.

In those terms, the "selection pressures" in modern society that would manifest depression in those susceptible individuals may not have been fully present in prior times, which allowed the gene(s) responsible for it to continue to propagate throughout subsequent generations.

~Dr. Imago

[Cavemonster]

I think their is obviously a clear advantage to our brains in general, with their fantastic pattern finding and problem solving abilities.

And the flip side to having a complex and slightly delicate organ like that is that there is a possibility of specific things going wrong.

Sort of like in luxury cars, there is a great advantage to the complex, computer controlled systems which manage air conditioning, fuel usage, and the performance, breaking and safety of the car in wonderful ways. However, having this complex computer system means that your car can end up in the shop if it's delicate bits are damaged, and your car can cease to "think" properly. Whereas, I could build an amazingly sturdy car with just a motor and an on/off switch that would be only malfunction, rarely, on a very simple and easy to fix level.

Mental illness is an emergent property of having a complex and delicate organ in our noggins, but the advantages of that organ are more of an evolutionary advantage than the drawbacks of it's misfirings.

[Iconoclast08]

Does depression have any evolutionary advantage? I was just wondering why it persists in Humans, when it really destroys your desire to do anything, including reproduction.

Evolutionary psychologists have a ball making stuff up about how things like depression and schizophrenia may have been adaptive in the past. My beef is that these sorts of explanations are extraordinarily tough to verify, especially in the absence of corroborating historic data.

It mostly becomes a free-for-all in the sense of "what explanation sounds sexiest" and what can get published in the next issue of Psychology Today.

Clearly, I'm pretty anti-ev psych. Other folks on this forum likely can give you a more balanced view.

[Undesired Walrus]

Thought it may be like sickle-cell anemia, something that appears to be a disadvantage but actually allows people to reach reproduction age.

[Rrose Selavy]

Found this but haven't had a chance to read it fully yet.

http://www.staff.ncl.ac.uk/daniel.nettle/journal%20of%20affective%20disorders.pdf

[Wowbagger]

"Depession" is not one type of thing. There are many different types of depression, each one probably with a different explanation behind it.

Depression, like all emotions, is an emergent property of so many different factors, it is generally going to be difficult to sort it all out. This is true of those with specific chemical triggers associated with them, or not.

However, it is not a hopeless mess. The more progress we make, the better predictions we can develop for its occurance, and the better our treatments and preventative measures will be.

[Kaylee]

Someone who is prone to only mild depression may attempt to “self-medicate” by being physically active, eating very healthy foods, and cultivating strong friendships. All of those things can help people, including people prone to mild depression, feel better and also have an evolutionary advantage.