WRAP is a registry of people who have/had a parent diagnosed with Alzheimer's disease. This group will be studied over time because of their increased risk of developing the disease. To become a participant of WRAP you must be between the ages of 40 to 65, have a parent diagnosed with Alzheimer's disease or have a mother who lived to age 75 or greater and a father to age 70 or greater WITHOUT memory problems. Current recruitment includes African-Americans and English-speaking Hispanics/Latinos whose parent(s) developed Alzheimer's disease and persons whose parents did NOT develop Alzheimer's disease or dementia (controls). Call for more detail.