The purpose of this study is to determine if there is improvement or measurable change in cognition after only one month of treatment with donepezil when using a computerized test battery. The results at one month will be compared with the results at 3 months to evaluate this.

Inclusion Criteria:

• Clinical diagnosis of probable AD according to NINCDS-ADRDA criteria.
• The patient should live with an appropriate caregiver at home, or in a community dwelling. A caregiver should be capable of accompanying the patient to clinic visits or attending study visits in the patient's home.
• Patient and caregiver should understand, speak, and read local language.

Exclusion Criteria:

• Significant neurological disease or dementia other than AD, e.g., mixed dementia, frontotemporal dementia, and Parkinson's Disease.
• Females of child bearing potential
• Impaired vision or hearing