Intensive Instruction on the Use of Aricept

Inclusion Criteria: * Diagnostic evidence of probable Alzheimer's type Dementia consistent with DSM-IV. * Written informed consent will be obtained from subject (if possible) or from the subject's legal guardian or other representative (according to Japanese regulations as appropriate) prior to beginning screening activities. * Patients having caregivers who submit written consent for cooperative involvement in this study, can provide patients' information necessary for this study, assist treatment compliance, and escort patients on required visits to study institution. * Outpatients in their own home. Exclusion Criteria: * Patients treated with donepezil, galantamine, rivastigmine in 4 weeks immediately before enrollment. * Known hypersensitivity to donepezil or piperidine derivatives. * Involvement in any other investigational drug clinical trail during the preceding 12 weeks.