Comparative neuropsychological function in obsessive-compulsive disorder and schizophrenia with and without obsessive-compulsive symptoms

Executive function deficits are seen in both schizophrenia and obsessive-compulsive disorder (OCD), but research suggests that dorsolateral prefrontal (DLPF) dysfunction is associated with schizophrenia and orbitofrontal (OBF) dysfunction is associated with OCD. As part of a comprehensive neuropsychological assessment, the Bechara Gambling Task (BGT) was used to assess OBF function and the Wisconsin Card Sorting Test (WCST) was used to assess DLPF function among three groups: 26 individuals with schizophrenia/schizoaffective disorder with obsessive-compulsive symptoms (SCZ+), 28 individuals with schizophrenia/schizoaffective disorder without obsessive-compulsive symptoms (SCZ-), and, 11 individuals with OCD. It was predicted that the SCZ+ group and the OCD group would show impairments in OBF function, as compared to the SCZ- group, and that the SCZ+ and SCZ- groups would show impairments in DLPF function, as compared to the OCD group. It was also predicted that the SCZ+ group would perform more poorly than the SCZ- and OCD groups in a number of other cognitive domains. Contrary to expectation, no divergence between groups was seen on tests of executive function. Instead, there was a statistical trend for the SCZ+ and SCZ- groups, when combined, to perform worse than individuals with OCD on the measure of OBF. Although not significant at the designated alpha level, the profile results showed that the SCZ+ group performed slightly below the OCD and SCZ- groups across nearly all neuropsychological domains.