It is a conundrum that has puzzled mankind since at least Plato and Aristotle.
Why do so many creative people throughout history — so many great artists and geniuses such as Robin Williams — seem to be touched by what the ancient Greek thinkers called "divine madness"?
And which came first for those graced by this "gift from the gods" — the genius or the madness?
Twenty-four centuries later, we are still puzzling, reminded once again of the seeming link between creativity and mental illnesses by the shocking suicide of Williams this week in his California home. He was 63, had long battled substance abuse and had recently sought treatment for depression.
Instantly, we recalled other artists who followed the same tragic path, a lengthy list that includes painters, poets, writers, musicians and designers: Vincent van Gogh, Ernest Hemingway, Virginia Woolf, Sylvia Plath, Kurt Cobain, Alexander McQueen to name just a few of the famous creatives who suffered from depression and committed suicide.
But is there a proven link between creativity and mental illness (which, strictly speaking, is not the same as being mad)? This is still a matter of hot debate.
A leading researcher in this field is Kay Redfield Jamison, a professor at Johns Hopkins University School of Medicine (who herself has bipolar disorder) whose studies seem to back up the popular idea of the "tortured genius." When, for example, she examined nearly 50 writers and artists in Britain, she found that more than 38% had been treated for a mood disorder.
On the other hand, some experts find this discussion absurd, such as psychologist Judith Schlesinger, author of 2012's The Insanity Hoax: Exposing the Myth of the Mad Genius.
She blames "misinterpretation" of what Plato meant, plus the fact that no one even agrees on what constitutes creativity or madness.
"There is no evidence...that a poet or comedian is any more disturbed than the mail carrier," she says. "People (are) asserting creative people (are) more prone to mental illness without a shred of proof. But the myth is so beloved and so ancient that people figure it must be true and there must be evidence."
Still, it's hard to argue with people's instincts.
"I don't think a couple of thousand years of human observation that there's something going on, is off," says Constance Scharff, director of addiction research at Cliffside Malibu, the celebrity rehab center in California that treats patients with addiction and psychiatric issues. "It's only in the last 10 years that we've had the scientific knowledge to prove the link, through neuroscience and brain imaging, but there's no doubt there's a connection."
But its exact nature is still unclear. Science and medicine are only now beginning to study what's going on — chemical, neurological, organic — in the brain, and also deal with the old and vexing problem of a cure: How to treat creatives successfully in a way that does not rob them of their creativity?
Call it the Hemingway problem: "They think, 'If I stop drinking I won't be able to write,' " says Scharff.
Psychotherapist Deb Serani, author of Living With Depression (and who nearly killed herself while in a depressed state at age 19), says people with bipolar disorders find ways to cope when they're in a manic stage.