Nearly every depressed person is assured by doctors, well-meaning friends and family, the media, and ubiquitous advertisements that the underlying problem is a chemical imbalance. Such a simple defect should be fixable, yet despite all of the resources that have been devoted to finding a pharmacological solution, depression remains stubbornly widespread. Why are we losing this fight?

In this humane and illuminating challenge to defect models of depression, psychologist Jonathan Rottenberg argues that depression is a particularly severe outgrowth of our natural capacity for emotion. In...