Are there sex differences in neuropsychological functions among patients with obsessive-compulsive disorder?

The purpose of this study was to examine whether men and women with obsessive-compulsive disorder (OCD) demonstrate differences in neuropsychological functioning compared to healthy men and women. Participants were 56 consecutive patients (33 male, 23 female) and 40 healthy control participants (20 male, 20 female) of comparable characteristics. Male and female patients had comparable symptom severity, illness duration, comorbidity, in- or out-patient status, and medication usage. An extensive neuropsychological test battery was administered including tests of general nonverbal intelligence, attention, verbal and nonverbal memory, and executive functions. Male and female OCD patients showed comparable neuropsychological performances on most cognitive domains. However, we found some evidence for cross-sex shifts in verbal fluency tasks (FAS and Category Alternation Test [CAT]), the reading component of the Stroop test, and the Wechsler Adult Intelligence Scale-Revised (WAIS-R) Digit Span-Forward test. Post hoc analyses revealed that female patients showed reduced performance on these tests compared to healthy women, in the male-typical direction. Among OCD women only, there were significant negative correlations between OCD symptom severity and performance on the CAT and the reading Stroop. We conclude that sex does not seem to be a major determinant of neuropsychological function in OCD, but the observed cross-sex shifts on some tasks deserve further examination.