Few conditions are as fascinating to a psychologist as obsessive-compulsive disorder (OCD), and few generate as much controversy. Experts disagree over topics related to classification, etiology, and treatment, and differing points of view also occur along disciplinary lines between psychology and psychiatry. Because of the insularity of various scientific communities that study OCD, there is rarely a forum for examining these issues from various perspectives, and for trying to provide a more complex and multifaceted picture of the disorder. This volume creates such a forum.