Efficacy and safety of long-acting risperidone in stable patients with schizoaffective disorder

BACKGROUND: The treatment of schizoaffective disorder is often complicated by the variety of symptoms that contribute to its pathology. Data from a large study (n=725), which included schizoaffective patients to assess the effect of long-acting risperidone, are presented. METHOD: A multicenter, open-label study enrolled non-acute, clinically stable patients with schizoaffective disorder (n=110). Patients on a stable dose of antipsychotic for at least 4 weeks at study entry were switched to long-acting risperidone every 2 weeks for 50 weeks. RESULTS: Mean Positive and Negative Syndrome Scale (PANSS) total scores (+/-S.E.) improved significantly (p<0.001) at each measured time point, including endpoint (-9.0+/-1.6), compared with baseline. Significant reductions were observed on mean PANSS cluster scores for both anxiety/depression (-1.3+/-0.4, p<0.001) and uncontrolled hostility/excitement (-0.7+/-0.3, p<0.05). In addition, scores improved significantly for positive symptoms (-2.2+/-0.5, p<0.001), negative symptoms (-3.1+/-0.5, p<0.001), and disorganized thoughts (-1.7+/-0.4, p<0.001). The overall subjective score of movement disorders was low at baseline (3.6+/-4.1) and had significantly decreased at endpoint (2.75; p<0.05). Patients were previously treated with antipsychotics for 398+/-790 days before being switched to long-acting risperidone. LIMITATIONS: Although this was a 50-week study, which included over 100 patients with schizoaffective disorder, limitations include the open-label design and that it was not designed specifically to assess patients with this disorder. PANSS symptom domains previously defined by factor analytic methods were used for mood symptom measures. No specific mood symptom scales were administered in this study. CONCLUSION: Patients with schizoaffective disorder, considered stable on their antipsychotic medication at study entry, experienced additional significant clinical improvements and minimal side effects with injections of long-acting risperidone over a 50-week study period.