Aim: This literature review aimed to examine the relationship between cognitive impairment and obsessive-compulsive disorder (OCD). Studies based on neuropsychological testing were prioritized, but those dealing with clinical features, therapy, comorbidity, neuroimaging, and the families of OCD patients were also considered.

Materials and methods: The literature on cognitive impairment in OCD was reviewed and then the studies evaluating the relationship with these above mentioned findings were discussed.

Results: The clinically most important cognitive impairment in OCD is executive dysfunction, followed by impaired memory. Cognitive impairment has also been observed in the healthy relatives of OCD patients. Findings regarding the effects of comorbidity on cognitive function in OCD patients are inconsistent. Brain imaging studies suggest that frontostriatothalamic dysfunction might occur in OCD.

Conclusion: Executive dysfunction in OCD patients is well documented; however, the precise nature of the relationship between the severity of cognitive dysfunction and the clinical features of OCD are not well understood. Longitudinal family studies that employ both neuropsychological testing and brain imaging are needed to more clearly elucidate the relationship between cognitive dysfunction and OCD.