An important contribution to the ongoing debate over the origins of mental illness, this book is based on the largest study ever of identical twins in which one was ill and the other not. The book provides compelling evidence that both schizophrenia and manic-depressive disorder are biologically based diseases of the brain, unrelated to psychological influences.

An important contribution to the ongoing debate over the origins of mental illness, this book is based on the largest study ever of identical twins in which one was ill and the other not. The book provides compelling evidence that both schizophrenia and manic-depressive disorder are biologically based diseases of the brain, unrelated to psychological influences.