Some years ago Lewis Wolpert had a severe depressive episode: despite a happy marriage and a successful scientific career, he could think only of suicide. When he eventually recovered, he became aware of the stigma attached to depression and of how difficult it was to get reliable information. So he undertook this written investigation into what science and psychiatry - and his own personal experience - could reveal about depression. Now with an additional introduction following the associated BBC2 series, this work also recounts the author's struggle with a second bout.