Risperidone: how good is the evidence for efficacy?

This article reviews the published literature evaluating the efficacy of risperidone. The literature includes three multicenter, double-blind studies that compared risperidone, haloperidol, and placebo, as well as three comparisons of risperidone with a standard neuroleptic. Efficacy of risperidone is reported, but most studies involved chronically hospitalized patients who were relatively refractory; the response to standard neuroleptics was not robust. Also, the reported superiority of risperidone on negative symptoms may be artifactual, since standard neuroleptics, because of extrapyramidal symptoms, can mimic or exacerbate negative symptoms. Finally, risperidone may have an antidepressant effect. It is as yet unclear whether risperidone is as effective as standard neuroleptics for positive schizophrenia symptoms in neuroleptic-responsive patients.