The prevalence of insanity, which was once considerably less than one case per 1,000 total population, has risen beyond five cases in 1,000. Why has insanity reached epidemic proportions? What are the causes of severe mental illness? Why do we continue to deny the rising numbers, and how does this denial affect our ability to help those who are afflicted? In The Invisible Plague, E. Fuller Torrey and Judy Miller examine the records on insanity in England, Ireland, Canada, and the United States over a 250-year period, concluding, through both qualitative and quantitative evidence, that insanity is an unrecognized, modern-day plague. This book is a unique and major contribution to medical history. Until now, insanity, and its apparent rise over the centuries, has been interpreted as a socially and economically driven phenomenon. Torrey and Miller insist upon the biological reality of insanity and examine the reasons why its contemporary prevalence has been so profoundly misunderstood.