Book excerpt: This account of multiple personality disorder (MPD) and related dissociative disorders presents the latest findings leading to a new model of MPD and a new therapeutic approach to its treatment. The book examines the large cluster of symptoms and dysfunctions associated with MPD, focusing on diagnosis, clinical features, and the relationship of MPD to other diagnoses. Data and clinical evidence are presented for a widely-accepted, but as yet unproven hypothesis that MPD arises as a dissociative strategy for coping with severe childhood trauma, usually involving physical or sexual abuse.