Book excerpt: Providing clinicians and patients with the latest developments in research, this new edition is a succinct and practical introduction to the diagnosis, evaluation and management of OCD and other related disorders. Part of the Oxford Psychiatry Library series, this pocketbook includes individual chapters on the phenomenology, pathogenesis, pharmacotherapy and psychotherapy of OCD and other related disorders, and features fully updated content and research. The book also includes a helpful resources chapter, and an Appendix with summaries of the major rating scales used to assess patients with OCD, which will be of use to both clinicians and patients. Obsessive-compulsive disorder (OCD) and Obsessive-compulsive-related disorders (OCRDs) are anxiety disorders characterized by obsessions and compulsions, and varying degrees of anxiety and depression. OCRDs are considered to be one of the most disabling of psychiatric disorders and they present a tremendous economic and social burden, both for the affected individual, their family, and for society at large. In contrast to other psychiatric conditions of a comparable or lesser prevalence and patient burden, relatively little is understood about the aetiology, and cognitive effects of OCRDs.