Alzheimer's disease is a neurological disorder which causes the death of cells and memory loss and change in behavior. A person can live with Alzheimer's disease for just a few years. More often, however, people live with it for about 9 years. About 1 in 8 people age of 65 and over has the disease. It is the most common type of dementia, accounting for 60 to 80 percent of cases of dementia in the United States.