ABSTRACT
The aim of this study was to compare the effects of olanzapine versus haloperidol to control the signs and symptoms of stuttering. Ninety-three patients were recruited in a 12-week single-blind randomized clinical trial, which was held between October 2009 and October 2010. Forty-three patients received olanzapine [5 mg/day] and 50 patients, haloperidol [2.5 mg/day]. Before and after the study, they were evaluated by a speech pathologist by Van Riper's questionnaire. The data were analyzed using the SPSS version 16. T-test was used to compare the data between the two groups. Mean of stuttering score [SD] before treatment was 4.67 [0.81] and 4.40 [1.14] in haloperidol and olanzapine groups, respectively [P > 0.05]. After treatment, the mean [SD] score was 2.87 [1.32] and 1.56 [0.71] in haloperidol and olanzapine groups, respectively [P = 0.000]. It seems that olanzapine does have better impact in controlling stuttering, and it may be recommended to prescribe olanzapine for stutters as the first choice to control the stuttering under a careful follow-up