A comprehensive introduction to one of the most common psychiatric disorders, a condition that results in intrusive, irrational thoughts and/or repetitive, illogical physical or mental actions. Titles in this Health and Psychology Sourcebooks series address psychological, physical, or environmental conditions that threaten human health and wellbeing. This book presents a comprehensive overview of OCD—one of the five most common psychiatric disorders. Obsessions range from those associated with contamination, safety, and order or symmetry to scrupulosity, or the need the do the "right" thing. Compulsions range from counting, touching, and tapping to excessive cleaning/washing, arranging, or even hoarding. Written by a therapist among the most experienced in the world in dealing with this disorder, this book covers the incidence, symptoms, diagnosis, history, development, and causes, as well as the effects and costs of OCD. It also addresses theory, research, and treatments and offers insight into and case studies illustrating how the disorder displays in society, at work, and in relationships. A glossary of terms, suggested further readings, and resource websites and organizations listing are included.