So how does suicidal ideaton fit with this? Is the benefit of hibernation that much higher than the probability of killing oneself? Also why does being depressed feel miserable then, sleeping for example is a very enjoyable experience, at least for me.
Side effects: Our brains are machines that sometimes have very crude control mechanisms. Floods of certain neurotransmitters to enrage us, others to make us feel love and lust. The sort of chemical conditions necessary to encourage torpor and cautious behavior also make us "sad".
Since there are intelligent people here who follow the topic of evolutionary psychology, I'd like to hear opinions about some research from 2009. Particularly if this idea seems reasonable or not, but possibly other opinions that people might have about it.
The idea is a variation on one that's somewhat popular here: that some conditions usually regarded as mental illnesses (Asperger's for example) are beneficial, even adaptive. But the condition in question now is depression. Briefly, the argument is that depression, at least when it is a response to stimuli and not a permanent feature, can have the useful effect of encouraging more rational thought when this is particularly important, even at the cost of quality of life, and that this is adaptive.
Links: a Scientific American article, a journal article (which I haven't read, behind a $12 paywall). Here's the abstract of the journal article:
The full journal citation is Andrews, Paul W., and Thomson Jr., J. Anderson; July 2009; Psychological Review 116 (3), 620–654; doi 10.1037/a0016242.