Cognition and neurocognition: effects of risperidone, olanzapine, and haloperidol

Objective: This study examined the short-term effects of first- and second-generation antipsychotic medications on social cognition and basic cognition. Method: One hundred patients with schizophrenia or schizoaffective disorder participated in an 8 week, double-blind study of risperidone, olanzapine, and haloperidol. Participants were administered multiple measures of social cognition, basic cognition, and clinical symptoms at baseline, the end of week 4, and the end of week 8. Seventy-three patients completed the baseline assessment and at least one other assessment. Data were analyzed with mixed-effects analyses of co-variance. For data reduction, the social cognitive measures were clustered into a summary score, and the cognitive measures were clustered into two summary scores: general cognitive ability and processing speed. (The effects on thinking of risperidone and olanzapine can be found at NCT00108368, www.clinicaltrials.gov.) Results: There were no treatment-related differences on any of the three summary scores. Social cognition did not show within-group changes over time either by itself or after control for the cognitive clusters. One cognitive score (general cognitive ability) increased during the study period for all three medication groups. Conclusions: The present study included a rather thorough assessment of social cognition and did not find any evidence of between-group or within-group effects of antipsychotic medication on social cognition.