Over on the BPS Research Digest, they have an article on the Line Between Artist and Madman. Apparently artists and schizophrenics share a lot of similar experiences, with a single exception. Apparently the line which separates an artist from a mad(wo)man is introvertive anhedonia—a condition where one lacks motivation and emotion.

As an aside, check out the Art of Louis Wain, an Artist who started out "normal", but developed schizophrenia as he aged. Pictured to the right is a 'stage 2' drawing of a cat. Check the link for even crazier kitties.