To Bruce Goldstein-an edgy, twenty-something New Yorker trying to make his mark in advertising-just waking up in the morning was an ordeal. Underemployed and recently dumped, he was well into the downward spiral of bipolar disorder. Even with therapy, lithium, Paxil, Wellbutrin, and Prozac, he could not shake his rapid mood swings, his fear of dying, or the voice of Satan, who first visited him one sunny day in Central Park. Then came Ozzy, a black...