Efficacy and Safety of Risperidone in the Treatment of Schizoaffective Disorder: Initial Results From a Large, Multicenter Surveillance Study

Background: An adequate therapy for psychotic disorders needs to be effective against mood as well as psychotic symptoms. Analyses of data from clinical trials of risperidone in schizophrenia and small open-label studies in mania suggest that risperidone may have this broad efficacy profile. We present data on a 6-week trial of risperidone for the treatment of schizoaffective disorder that was part of a larger, 6-month surveillance study of patients with affective disorders.

Method: One hundred two patients suffering from schizoaffective disorder (DSM-IV or ICD-10) entered the trial. Inclusion criteria consisted of a current DSM-IV diagnosis of schizoaffective disorder, bipolar type; DSM-IV manic or mixed psychotic episode; and a Young Mania Rating Scale (YMRS) score > 7 for a mixed episode (> 20 for a manic episode). Assessments included the YMRS, the Positive and Negative Syndrome Scale (PANSS), the Hamilton Rating Scale for Depression (HAM-D), the 4-item Clinical Global Impressions (CGI) scale, and the UKU Side Effect Rating Scale subscale for neurologic side effects. For patients entering the study, open-label risperidone therapy was added to their existing regimens of mood-stabilizing treatments. Other antipsychotic drugs were not allowed.

Results: Ninety-five patients completed the 6-week trial. At week 6, the mean ± SD dose of risperidone was 4.7 ± 2.5 mg/day. The mean scores on the assessment scales at baseline and week 6 (unless otherwise stated) were as follows: YMRS, 22.7 and 4.7, an improvement of 18.0 points (p < .0001); PANSS (at baseline and week 4), 74.1 and 54.2, an improvement of 19.9 points (p < .0001); HAM-D, 14.0 and 7.4, an improvement of 6.6 points (p < .0001); CGI (at baseline and week 4), 2.6 and 1.7, an improvement of 0.9 points (p < .0001). At week 4, most patients had shown improvement in symptom severity, and 9.3% were completely symptom-free. There were no statistically significant differences between baseline and week 4 in the severity of extrapyramidal symptoms as measured by the UKU. Risperidone was well tolerated; side effects were few and generally mild.

Conclusion: The results to date with risperidone indicate that it may have both antipsychotic and mood-stabilizing properties. Despite the limitations of the open-label design, the results indicate that risperidone is a safe and effective therapy in combination with mood-stabilizers for the treatment of patients with manic, hypomanic, and depressive symptoms of mixed episodes in schizoaffective disorder, bipolar type.