The Relationship Between Risperdal Treatment and Quality of Life in Patients With Alzheimer's Disease and Behavioural and Psychological Symptoms of Dementia (BPSD)

Inclusion Criteria: 1. Male or female patients whose age 60 years or older diagnosed with Alzheimer's disease and BPSD without exposure to any antipsychotics within 1 month prior to study start. 2. Subjects and subjects' relatives or legal representatives have signed the informed consent form, in accordance with the regulations of the local ethical committee. 3. Subjects must remain in good health, as determined by medical history, complete physical examinations, laboratory tests and ECG. Exclusion Criteria: 1. Neurodegenerative disorders such as Parkinson's disease, Pick's disease or Huntington's chorea, Down's syndrome, Creutzfeldt-Jacob disease. 2. One of the following conditions possibly resulting in cognitive impairment: Acute cerebral trauma caused by post traumatic brain injury, subdural hematoma and injuries secondary to chronic trauma; hypoxic cerebral damage;; cerebral neoplasia;; mental retardation or oligophrenia 3. Multi-infarct dementia or clinically active cerebrovascular disease 4. Subjects with the severe co-existing medical conditions. 5. Current clinically significant cardiovascular disease that would be expected to limit the subject's ability to participate in and complete a 3-month trial. 6. History of drug or alcohol abuse within the last year. 7. Female subjects of childbearing potential without adequate contraception. 8. History of severe drug allergy or hypersensitivity; including recorded hypersensitivity to Risperidone. 9. Participation in a clinical trial of any investigational drug within 1 month (30 days) prior to study entry.