/lit/ - Literature

I'm interested in the psychology that drives those of us who write. Most writers I meet don't even "like" writing, it's a compulsive need. Where as others might be gluttons, or enjoy some sport or hobby, writers seem to write because it's innate to them and they have to do it.
They almost always, without fail, seem miserable on top of this. It's true of your average no name writer, and all the greats; the most treasured writers seem to increase in quality in direct proportion to their misery or bleakness. Dostoevsky was better than Tolstoy, and it's because he was "le sad."
What makes us like this? Why does this strange mix of self awareness and melancholy, even patheticness, seem to produce such generative, beautiful lines of work coming out of a person?
Maybe you don't agree, I'd like to hear that too. What is behind the psychology of the "writer?"