Alzheimer's disease (AD) is a debilitating, life-altering disease that attacks the brain. Its primary symptom is progressive memory loss, but difficulties with vision, language, skills, and emotional control are also common. The progressive deterioration continues for five to 20 years. At some point, a person with Alzheimer's disease will require 24-hour care and assistance with daily activities such as eating, grooming, and toileting. Because its impact on the affected person is so great, it profoundly affects family and caregivers.

About four million Americans have Alzheimer's disease. That number will likely increase to at least seven million by the early 21st century unless researchers find a cure or a way to prevent the disease.

Age is clearly the major risk factor for Alzheimer's disease. While only five percent of those over 65 have the disease, nearly half the population over 85 have it. Genetics also appears to play an important role. The course of Alzheimer's disease varies tremendously, but is always progressive. The disease claims more than 100,000 lives per year - the 4th leading cause of death for adults.