Effect of antipsychotic drugs on cortical thickness. A randomized controlled one-year follow-up study of haloperidol, risperidone and olanzapine

Abstract Background Imaging evidence indicates that brain alterations are primary to the full-blown onset of schizophrenia and seem to progress across time. The potential effects of antipsychotic medication on brain structure represent a key factor in understanding brain changes in psychosis. We aimed to investigate the effects of low doses of haloperidol, risperidone and olanzapine on cortical thickness. Method We investigated the effects of risperidone (N = 16), olanzapine (N = 18) and low doses of haloperidol (N = 18) in cortical thickness changes during 1-year follow-up period in a large and heterogeneous sample of schizophrenia spectrum patients. The relationship between cortical thickness changes and clinical and cognitive outcome was also assessed. A group of 45 healthy volunteers was also longitudinally evaluated. Magnetic resonance imaging brain scans (1.5 T) were obtained and images were analyzed by using BRAINS2. Results There were no significant effects of time (F1,47 < 1.66; P > 0.204), treatment group (F2,47 < 1.47; P > 0.242) or group-by-time interaction (F2,47 < 1.82; P > 0.174) for any of the cortical thickness variables. When the group of healthy controls was included in the analyses, it is of note that group-by-time interaction showed a significant result for the frontal lobe at trend level (F3,81 = 2.686; P = 0.052). After the Bonferroni adjustment for multiple comparisons, there were no significant associations between changes in cortical thickness and clinical and cognitive outcome. Conclusions Low doses of haloperidol, risperidone, and olanzapine seem to equally affect gray matter cortical thickness, overall and lobes, at the medium-term (1 year). The clinical effectiveness of treatments was not significantly related to changes in cortical thickness.