About one American in five receives a diagnosis of major depression over the course of a lifetime. That's despite the fact that many such patients have no mood disorder; they're not sad, but suffer from anxiety, fatigue, insomnia, or a tendency to obsess about the whole business. "There is a term for what they have," writes Edward Shorter, "and it's a good old-fashioned term that has gone out of use. They have nerves." In How Everyone Became...