• (this is a theory of mine. it's not very deep, but it's interesting.)

i think depression is an evolutionary adaptation and a necessary mechanism to help good genes survive; it's so common, so specific, and has such consistent logic that it must be programmed into us.

i saw an interesting talk recently about the current developments in neuroscience, and the speaker mentioned a study which revealed the fact that the activity patterns that represent the feelings of being excluded from social groups are the same as those of experiencing actual pain.

now, this is an odd way for the brain to function. why would you want excluded people to feel actual pain?

well, i thought about it, and since this pain signal comes from deep within the early recesses of our animal brain, it seems that this is probably an adaptation to keep the genes of people who are socially maladapted or who cause trouble out of the gene pool.

so, the reason depression can completely sieze somebody and make them want to commit suicide is because it's a feedback loop. a depressed person is unhappy, which makes them no fun in social situations, which leads to them being ostracised, which leads to them being more depressed, until they actually kill themselves.

when i'm depressed, i don't want to eat, life seems pointless, i'm incapable of doing simple tasks, i stop caring about my appearance, no interest in sex... i'm basically completely unfit-to-survive. it's like sabotage!

when a person is in a doomed situation, like when you just got partially mauled by a bear and you're lying there bleeding and in great pain, this kind of acceptance of death comes over you. i'd imagine that mechanism is also being used in the depressed person, which is why you don't want to eat or take care of yourself. you're just trying to speed up the inevitable and minimize pain. by having social rejection directly tied into the same pain centres causes the same series of things to happen, which basically results in you giving up on life and ending it quickly without a fight.

it makes sense though when you imagine back to ancient human societies where the community had to work together to survive. you had to depend on others for everything -- farming and getting food, clothing yourself or getting logs, etc. it was a completely different experience. if you were ostracised in this kind of a community, it was either because you were a total burden, or a witch!

it's also interesting that anything that makes you less capable of survival makes you depressed... i.e. not being productive, failing at something you wanted to do, etc.

the only thing that could keep someone alive after being ostracised is some delusion that they're actually great and the world just doesn't understand them. if they're lucky, they're right, and they go down in history as the greatest person who's ever lived. if they're unlucky, they just end up being a person with a lot of cats. either way, they manage to stick around.

of course, that delusion can be the truth nowadays. people can feel ostracised for no reason. our world is becoming less communal and more isolated, and someone who's perfectly normal and just happens, through some bad turn of luck, to have no real friends, could be artificially induced to get this kind of depression.

i mean, the statistics say it all -- 1 out of 4 americans has some form of a mental illness.