Neuropsychological functioning in obsessive-compulsive disorder: are executive functions the key deficit?

Although several studies have examined neuropsychological functions in obsessive-compulsive disorder (OCD), findings are not conclusive, predominantly due to small samples and assessment of limited domains. We aim to map the neuropsychological profile of OCD in a large sample with a comprehensive battery of tests.

Neuropsychological functions were tested in 150 subjects with DSM-IV OCD and 205 healthy control subjects.

Subjects with OCD performed significantly worse than healthy control subjects on Colour Trails 1 time, Tower of Hanoi 3-disk time, Wisconsin Card Sorting Test categories completed, Iowa Gambling Task, Complex Figure Test immediate and delayed recall (p<0.001).

Subjects with OCD evince deficits in scanning, planning time, concept formation, decision making and encoding of non-verbal memory after controlling for the effects of age, gender and education. The profile is suggestive of a predominantly executive dysfunction, with difficulties in strategizing and organizing stimuli and cognitive resources for maximum efficiency. The findings implicate dorsolateral prefrontal, superior medial prefrontal and anterior cingulate cortices, suggesting that OCD might not be a purely orbitofronto-striatal disorder as previously conceptualized.