There is a connection between creativity/intelligence and mental illness. There's a book by Kay Redfield Jamison called Touched With Fire that examines the link between creativity and mental disorders such as depression and bipolar. Try googling the book, the link I found was too long.
(Before I begin my rant, I want to say the connection I make with readers is that I'm working under the assumption that said readers are intelligent, more so than your average human being. This is how what follows relates to the thread)
I've had this discussion with people before, and I believe the suspected connection between mental disorders and intelligence has to do with mental capacity, which I understand is what true intelligence is based on. Mental illness is genetic, but it's also something that is normally *triggered*, manifesting at some point in time. One can have the predisposition for an illness through genetics, but it may never manifest, like a genetic alcoholic who never takes a drink. The intellectual ability to see further into things, to be capable of a deeper understanding of the various aspects of the world, I believe, can lead to mental disorders.
Around the time my bipolar manifested, the Matthew Shepherd murder occurred, and it hit me very deeply. It was the first time something outside my personal bubble had, in a word, penetrated me. I didn't understand how my classmates weren't affected by the knowledge of this kind of hate and violence in the world. It's as if this kind of understanding not only breaks open new caverns of deeper, more fulfilling thought and consciousness, but also breaks open far more savage caverns in the mind, those leading to chemical imbalance. My mother called this sort of thing a balancing out of the universe.
However, I'm not a doctor. This is just my opinion, I could be wrong.
