(Note: This program first aired last year.) We're now undergoing a worldwide mental health crisis; across the board, mental illnesses are clearly on the rise. But what causes mental illness? And why are mental health problems so hard to treat? On this episode of STMM, we discuss a book that might well change how the medical establishment understands, defines, and treats mental health. Our guest is Dr. Christopher M. Palmer, a Harvard psychiatrist and researcher working at the crossroads of metabolism and mental health. His book is "Brain Energy."