A fear of contamination drives the most common manifestation of obsessive compulsive disorders(OCD), compulsive washing. OCD is a distressing anxiety disorder that affects 1-2 percent of the population and can be disabling. Intense and complex forms of the disorder benefit from advanced analyses of contamination and its treatment. This book, part of a series on modern psychological treatments published by OUP, provides a detailed account of the nature and causes of the various forms of a fear of contamination and their consequences. Methods of treatment are described and fully illustrated by case histories. The inclusion of original analyses and explanations of a newly recognised form of the fear, mental contamination, is an important feature of the book and will enable therapists to expand their ability to assess and treat the abnormal fears of contamination. Written by clinicians with extensive experience, this volume is valuable for all clinical psychologists and psychotherapists with an interest in OCD