Obsessive-compulsive disorder, commonly called OCD, is a complex mental illness that involves repetitive thoughts (obsessions), which cause people to perform repetitive acts (compulsions) in an effort to seek relief. Through objective overviews, primary sources, and full-color illustrations, this title examines What Is Obsessive-Compulsive Disorder? What Causes Obsessive-Compulsive Disorder? What Problems Are Associated with Obsessive-Compulsive Disorder? and Can People Overcome Obsessive-Compulsive Disorder?