The neuropsychology of obsessive-compulsive disorder: a review and consideration of clinical implications.

Clinicians have suspected that obsessive-compulsive disorder (OCD) is associated with fundamental information-processing deficits beyond those attributable to mood disturbance alone. Neuropsychological investigations can be divided into four broad areas concerned with general intellectual functioning, an 'under-inclusive' thinking style, performance on tests sensitive to frontal lobe impairment and performance on tests of memory. This body of research is critically reviewed. It is suggested that there is modest evidence for the presence of non-verbal and praxic memory deficits in patients with OCD. These deficits are consistent with contemporary theories of fronto-striatal functioning and may represent the cognitive substrate of doubt-related phenomena such as checking. The demonstration of specific memory impairments in OCD may have significant implications for the revision of existing models of OCD and the development of novel treatment strategies that reduce doubt in compulsive checkers by increasing the distinctiveness of past actions.