Obsessive–Compulsive Disorder

Obsessive-compulsive disorder (OCD) is a very common disease that affects approximately 2–3 % of the general population across the lifespan [APA (Diagnostic and statistical manual of mental disorders. APA, 1994)]. OCD has been listed as one of the ten most disabling illnesses by the World Health Organization [Murray and Lopez (Science 274(5288): 740–743, 1996)], while the National Comorbidity Survey Replication identified it as the anxiety disorder with the highest proportion of serious cases (50.6 %) [Kessler et al. (Arch Gen Psychiatry 62(6): 617–627, 2005)]. Many individuals with OCD receive markedly delayed diagnosis and treatment for this illness [Jenike (N Engl J Med 350(3): 259–265, 2004)]. Although it has a waxing and waning course, it frequently increases in severity due to ritual reinforcement when left untreated. Hence, improved understanding of OCD by clinicians is imperative to reduce the gap between symptom onset and eventual diagnosis and to promote early implementation of strategies for long-term symptomatic relief. This chapter will provide a general description of clinical features, assessment strategies, and treatment of OCD.