This article (via ALDaily) might explain the correlation there seems to be between mental-illness/depression and creativity:
[T]he brain’s dopamine (D2) receptor genes [...] experts believe govern divergent thought.
[Associate Professor Fredrik Ullen] found highly creative people who did well on tests of divergent thought had a lower than expected density of D2 receptors in the thalamus – as do people with schizophrenia.
The thalamus serves as a relay centre, filtering information before it reaches areas of the cortex, which is responsible, amongst other things, for cognition and reasoning.
“Fewer D2 receptors in the thalamus probably means a lower degree of signal filtering, and thus a higher flow of information from the thalamus,” said Professor Ullen.
And then:
“Creativity is uncomfortable. It is their dissatisfaction with the present that drives them on to make changes.
“Creative people, like those with psychotic illnesses, tend to see the world differently to most. It’s like looking at a shattered mirror. They see the world in a fractured way.
I’ve always wondered if depressed people (well, some/certain depressed people, some of the time) are dissatisfied with the present precisely because they’re not seeing the world in a fractured way; they’re seeing it raw. Ostensibly this makes sense; “functional” minds are filtering out certain information and thus not seeing as much.
It would make sense from an evolutionary perspective that we would normally filter out certain information: an individual that sees everything is going to see the futility of everything and thus not care about much. The most productive individual most likely to successfully propagate genes will be one which can be lied to; one with functional “D2 receptors.”
Happiness is a very contingent adaptation.
