Effect of risperidone on hostility in schizophrenia.

The objective was to examine effects of risperidone on hostility and compare these effects with those of haloperidol. On the basis of risperidone's pharmacologic profile, we hypothesized that risperidone has a selective effect on hostility and that this effect is greater than that of haloperidol. The data were obtained in a multicenter clinical trial of risperidone under placebo-controlled, double-blind conditions (duration, 9 weeks). The patients were 139 patients with the diagnosis of DSM-III-R schizophrenia. Hostility was measured by the "hostility" item of the Positive and Negative Syndrome Scale. Change in hostility served as a dependent variable in the analyses. Change in "psychosis" was applied as a covariate; it helped us examine changes in hostility that were unrelated to change in psychosis (selective effect). Risperidone had a greater selective effect on hostility than did haloperidol or placebo. This finding should encourage tests of risperidone as a treatment for patients who show frequent overt physical aggression.