It was difficult to secure enrollment of the targeted number of subjects.

To evaluate the efficacy (based on mean change in Cohen-Mansfield Agitation Inventory [CMAI] total score from baseline as the primary efficacy variable), dose-response, and safety of aripiprazole at 2, 3, and 6 mg/day in comparison with placebo in patients with agitation associated with Alzheimer's type dementia

This trial is a multicenter, randomized, double-blind, placebo-controlled, parallel-group, comparison trial to assess the efficacy and safety of aripiprazole in patients with agitation associated with Alzheimer's type dementia. Screening period is 4 weeks. Patients are randomly assigned to one of 4 groups, and treatment period is 10 weeks. Period of post-treatment observation is 30 days.

Inclusion Criteria:

• Patients whose legal representatives can provide informed consent (Informed consent from the patients where possible).

• Patients who satisfy both of the following diagnostic criteria:

  • Diagnosis of major neurocognitive disorder due to Alzheimer's disease according to Diagnostic and Statistical Manual of mental disorders (DSM-5)
  • Diagnosis of probable Alzheimer's disease according to National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA)

• Hospitalized patients or care facility patients

• Patients with an Mini-Mental State Examination (MMSE) score of 1 to 22

Exclusion Criteria:

• Patients with complications of dementia or memory impairment other than Alzheimer's type dementia
• Dementia patients with a Modified Hachinski Ischemic Score of 5 or higher
• Patients with psychological symptoms or behavioral disorders that are clearly due to other medical conditions or substances
• Patients with a complication or history of stroke or transient ischemic attack, except for asymptomatic stroke
• Patients with heart failure classified as New York Heart Asscoiation (NYHA） III or IV
• Patients who require drug therapy for arrhythmia or ischemic heart disease
• Body weight of less than 30 kg
• Patients with a high risk of suicide
• Patients with a complication or history of seizure disorder
• Patients with a complication or history of neuroleptic malignant syndrome, tardive dyskinesia, paralytic ileus, or rhabdomyolysis
• Patients with thyroid disease (except if the disease has been stabilized with drug therapy for 3 months or longer prior to time of informed consent)