Obsessions with contamination, hoarding objects and exact orderliness, and compulsions involving rituals of washing, cleaning, checking, re-checking and counting, are exhibited by children with Obsessive Compulsive Disorder (OCD). This volume draws on the latest research to aid clinicians in their diagnosis and treatment of children with this problem. Special features of the book include detailed case examples, measurement scales and a manual for a cognitive-behavioural treatment of this complex, puzzling disorder. The authors provide useful descriptions of childhood and adolescent OCD in its various forms, and discuss its etiology and epidemiology. In addition, they describe assessment methods and their usefulness in research and practice, and both pharmacological and psychosocial treatments.