Risperidone Safety and Efficacy in the Treatment of Bipolar and Schizoaffective Disorders: Results From a 6-Month, Multicenter, Open Study

Background: The goal of this study was to assess the efficacy and safety of risperidone in bipolar and schizoaffective disorders.

Method: 541 patients entered this open, multicenter, 6-month study. Patients were entered provided that they fulfilled DSM-IV criteria for bipolar disorder or schizoaffective disorder, bipolar type, during a manic, hypomanic, mixed, or depressive episode. Risperidone was added to any previous mood-stabilizing medication that the patients were taking. Efficacy was assessed with the Young Mania Rating Scale (YMRS), the Hamilton Rating Scale for Depression (HAM-D), the Positive and Negative Syndrome Scale (PANSS), and the Clinical Global Impressions scale (CGI). Extrapyramidal symptoms (EPS) were assessed using the UKU Side Effect Rating Scale.

Results: 430 patients completed the study. Addition of risperidone produced highly significant improvements (p < .0001) on the YMRS and HAM-D at both 6 weeks and 6 months and on the CGI and the scales of the PANSS at both 4 weeks and 6 months. There was a significant reduction in UKU total and subscale scores at 6 months. The mean dose of risperidone was 3.9 mg/day. There was no single case of new-emergent tardive dyskinesia, and there was a very low incidence of exacerbation of mania within the first 6 weeks (2%). Adverse events were few and mostly mild, the most frequent being EPS and weight gain.

Conclusion: This large study provides additional evidence that risperidone is effective and well tolerated when combined with mood stabilizers in the treatment of bipolar disorder and schizoaffective disorder, bipolar type. Previous concerns about exacerbation of manic symptoms were not confirmed.