Who Is Affected By Alzheimer's Disease

Estimates are that well over 2 million people in the United States have Alzheimer's disease, with 360,000 new cases occurring each year. The number of people with Alzheimer's is expected to quadruple over the next 50 years as the population ages. The National Center for Health Statistics ranks Alzheimer's disease as the ninth leading cause of death among Americans 65 years and older. The disease causes an estimated 22,725 deaths a year in the United States. Estimates of Alzheimer's disease and dementia in specific age groups vary, but in general, the numbers increase significantly in older age groups. Alzheimer's disease is uncommon in people younger than 65 and is rare before the age of 45. Close to half of the people with the disease are between the ages of 75 and 85. A recent review of population studies showed that Alzheimer's disease affects:

• 4.3% of people age 75.
• 8.5% of people age 80.
• 16% of people age 85.
• 28.5% of people age 90.

Other estimates are even higher. A rare, inherited form of the disease may affect some people as early as their 40s. This is called early-onset Alzheimer's disease.