Crazy But Talented

There seems to be a slight link between insanity and creativity. Many famous writers, poets and artists were mentally ill, such as Sylvia Plath, Virginia Woolf and Vincent Van Gogh. There are not only the creative but the Mathematically minded such as John Forbes Nash who is a famous Mathematician who suffers from schizophrenia.
Is there such a link? Do the mentally ill have hidden talents or the talented have hidden illnesses?
Apparently schizophrenics are usually rather artistic and creative and people who suffer with bipolar disorder, when on a high, can be very creative and motivated.
Those with depression can scribble out a poem that informs even the happiest of minds just how bleak life can be. So it's not all cheery.
But there seems to be some kind of link between the mentally ill and the talented.
I'm not saying I am talented though.