Antipsychotic Discontinuation in Alzheimer's Disease

In patients with Alzheimer's disease (AD) who respond to antipsychotic treatment of psychosis and/or agitation/aggression, the relapse risk after discontinuation is not established. AD patients with psychosis and/or agitation/aggression receive 16 weeks of open risperidone treatment (Phase A). Responders are then randomized, double-blind, to one of three arms in Phase B: (1) continuation risperidone for 32 weeks, (2) risperidone for 16 weeks followed by placebo for 16 weeks, (3) placebo for 32 weeks. The primary outcome is time to relapse of psychosis/agitation.