The purpose of this study is to learn more about two different types of psychotherapy to help individuals who have body dysmorphic disorder (BDD). BDD is a severe, often chronic, and common disorder consisting of distressing or impairing preoccupation with perceived defects in one's physical appearance. Individuals with BDD have very poor psychosocial functioning and high rates of hospitalization and suicidality. Because BDD differs in important ways from other disorders, psychotherapies for other disorders are not adequate for BDD. Despite BDD's severity, there is no adequately tested psychosocial treatment (psychotherapy) of any type for this disorder. This study will compare the effectiveness of Cognitive Behavioral Therapy and Supportive Psychotherapy as well as predictors of improvement.