Treatment for Aggression and Agitation in Patients With Alzheimer's Disease

The primary purpose of this study is to help answer the following research questions: * Whether this drug can help symptoms of aggression and agitation in participants with Alzheimer's Disease. * The safety of this drug and any side effects that might be associated with it. * How this drug compares to placebo. During the 12-week period of this study, the participant will have an equal chance of receiving 1 of the 2 treatment groups: active drug or placebo.