Background: Alzheimer's disease is the most common cause of dementia in older people. One of the aims of therapy is to inhibit the breakdown of a chemical neurotransmitter, acetylcholine, by blocking the relevant enzyme. This can be done by a group of chemicals known as cholinesterase inhibitors. Objectives: The objective of this review is to assess whether donepezil improves the well-being of patients with dementia due to Alzheimer's disease.