Cognitive and neurobiological findings in obsessive-compulsive disorder.

The behavioral disturbances seen in OCD patients likely are related to abnormalities in the frontal striatal systems, with complex involvement of other brain regions. This is suggested by data from various modalities. Executive deficits are seen on neuropsychological assessments, which may contribute to poor performance on tasks designed to test other domains. Studies of neurological illness in which obsessive and compulsive symptoms are seen with increased frequency and results of neuroimaging studies are also indicative of frontal-striatal dysfunction. Some neuroimaging studies specifically implicate the OFC, along with other regions such as the anterior cingulate cortex and caudate nucleus. Data from studies of neurological soft signs are less specific and suggest pathology that may be common to other psychiatric conditions, such as schizophrenia. Although data from these various modalities do not give clear guidance on treatment, future work may show usefulness of adding these assessments to a clinical evaluation,especially with respect to predicting treatment response in subtypes of OCD.