Biographers have long been interested in exploring the psychological issues that drove and afflicted great thinkers and achievers such as Charles Darwin and Albert Einstein. In her new book, Andy Warhol was a Hoarder: Inside the Minds of History’s Great Personalities, medical and science journalist Claudia Kalb looks at twelve famous figures and weighs the evidence suggesting that each suffered from a different kind of mental health condition. While not a business book per se, her work does have relevance as more people are becoming aware of mental illness as a workplace issue. Kalb spoke with HBR about how mental health conditions can be particularly relevant in understanding entrepreneurs. Edited excerpts: