Functional neuroanatomy of obsessive-compulsive disorder.

Although obsessive-compulsive disorder (OCD) was once considered rare, recent epidemiologic data suggest a lifetime prevalence rate of 2% to 3%. The morbidity associated with OCD is quite high compared to other psychiatric conditions. This report reviews neurologic, neuropsychological, and psychosurgical findings relevant to the functional neuroanatomy of OCD. In addition, it describes more recent investigations of OCD using a variety of brain imaging techniques, including computed tomography, positron emission tomography, and single photon emission computed tomography (SPECT). Finally, it examines the results of an ongoing pilot study of high-resolution, full-volume, three-dimensional SPECT imaging in patients with OCD before and after treatment with fluvoxamine.