Obsessive-compulsive disorders in children and adolescents often involve multiple obsessive thoughts and compulsive behaviors, and can prove to be very complex. The obsessive-compulsive symptoms frequently pose an extreme burden for the affected children and adolescents, as well as for their caregivers. As a result, there can be significant despair, aggression, and impairments in academic or professional relationships, as well as in peer or romantic relationships. The guide provides a practical approach to the diagnostic and therapeutic procedures for obsessive-compulsive disorders in childhood and adolescence. Initially, the volume informs about the current state of research regarding symptoms, classification, epidemiology, differential diagnosis and comorbidity, pathogenesis, as well as the course and treatment of the disorder. Detailed guidelines for diagnosis and therapy are thoroughly discussed.