Depression, once a subfield of neurosis, has become the most diagnosed mental disorder in the world. Why and how has depression become such a topical illness and what does it tell us about changing ideas of the individual and society? Alain Ehrenberg investigates the history of depression and depressive symptoms across twentieth-century psychiatry, showing that identifying depression is far more difficult than a simple diagnostic distinction between normal and pathological sadness – the one constant in the history of depression is its changing definition. Drawing on the accumulated knowledge of a lifetime devoted to the study of the individual in modern democratic society, Ehrenberg shows that the phenomenon of modern depression is not a construction of the pharmaceutical industry but a pathology arising from inadequacy in a social context where success is attributed to, and expected of, the autonomous individual. In so doing, he provides both a novel and convincing description of the illness that clarifies the intertwining relationship between its diagnostic history and changes in social norms and values. The first book to offer both a global sociological view of contemporary depression and a detailed description of psychiatric reasoning and its transformation – from the invention of electroshock therapy to mass consumption of Prozac – The Weariness of the Self offers a compelling exploration of depression as social fact.