Abstract
Introduction. Since a variety of comparisons between risperidone and olanzapine have resulted in diverse outcomes, so safety and efficacy of them were compared again in a new trial. Method. Sixty female schizophrenic patients entered into one of the assigned groups for random allocation to olanzapine or risperidone (n = 30 in each group) in a double-blind, 12-week clinical trial. Scale for Assessment of Positive Symptoms (SAPS) and Scale for Assessment of Negative Symptoms (SANS) were used as the primary outcome measures. Clinical Global Impressions-Severity Scale (CGI-S), Schedule for Assessment of Insight (SAI), and finally Simpson Angus Scale (SAS) as well were employed as secondary scales. Results. While both of olanzapine and risperidone were significantly effective for improvement of positive symptoms (P < 0.0001), as regards negative symptoms, it was so only by means of olanzapine (P < 0.0003). CGI-S and SAI, as well, were significantly improved in both of the groups. SAS increment was significant only in the risperidone group (P < 0.02). Conclusion. While both of olanzapine and risperidone were equally effective for improvement of positive symptoms and insight, olanzapine showed superior efficacy with respect to negative symptoms, along with lesser extrapyramidal side effects, in comparison with risperidone.