Risperidone for psychosis of Alzheimer's disease and mixed dementia: results of a double-blind, placebo-controlled trial

Abstract

To evaluate the efficacy and safety of low-dose risperidone in treating psychosis of Alzheimer's disease (AD) and mixed dementia (MD) in a subset of nursing-home residents who had dementia and aggression and who were participating in a randomized placebo-controlled trial of risperidone for aggression. This post-hoc analysis included only patients diagnosed with AD or MD with psychosis, defined by a score of >or= 2 on any item of the Behavioral Pathology of Alzheimer's Disease (BEHAVE-AD) psychosis subscale at both screening and baseline. Co-primary efficacy endpoints were changes in scores on BEHAVE-AD psychosis subscale and Clinical Global Impression of Change (CGI-C). Overall, 93 patients (46 risperidone and 47 placebo) fulfilled the psychosis of AD criteria. Mean change at endpoint in BEHAVE-AD psychosis subscale with risperidone was superior to placebo (-5.2 vs -3.3; p = 0.039). Distribution of CGI-C at endpoint also favoured risperidone (p < 0.001). The superior improvement with risperidone compared with placebo occurred as early as the first two weeks and persisted to the end of the treatment period. At endpoint, 59% of risperidone-treated patients were responders (i.e. were 'very much' or 'much' improved) compared with 26% of patients receiving placebo. The mean risperidone dose was 1.03 +/- 0.61 mg/day. Twelve weeks of treatment were completed by 37 patients treated with risperidone (80%) and 35 with placebo (74%). A total of 46 (98%) placebo- and 44 (96%) risperidone-treated patients experienced at least one adverse event, with only somnolence occurring more frequently in the risperidone group. Risperidone effectively reduces psychosis and improves global functioning in elderly patients with moderate-to-severe psychosis of AD and MD.