Are there reliable neuropsychological deficits in obsessive-compulsive disorder?

The aim of this study was to confirm in a large clinical sample that subjects with obsessive-compulsive disorder (OCD) have deficits on certain tasks of executive functioning, non-verbal memory, and/or motor speed. Our ultimate goal was to evaluate whether these deficits contribute to functional impairment and could be the target of a novel treatment intervention. Therefore, in a sample of convenience, the clinical characteristics and neuropsychological performance of adults with OCD and matched healthy controls were evaluated; neuropsychological tasks of executive functioning, non-verbal memory, and motor speed that have shown strong effects in prior studies were used. Primary analyses compared subjects with current OCD only (current-OCD, n=30), subjects with current OCD plus a comorbid disorder (comorbid-OCD, n=15), subjects with a history of OCD (n=15), and matched healthy controls (n=35). Secondary analyses examined whether clinical characteristics (e.g., OCD severity or medication status) were associated with neuropsychological performance. We found no significant overall differences in neuropsychological performance among the four groups. In pairwise comparisons, current-OCD subjects differed significantly from healthy controls only on the Benton Visual Retention Test. OCD severity had little effect and medication status had no effect on neuropsychological performance. In sum, contrary to our expectations, we found few differences in neuropsychological performance between OCD subjects and healthy controls. Whether there are reliable neuropsychological deficits in OCD that can be easily identified in a clinical sample and that contribute to functional impairment remains unclear and requires further study.