http://www.nia.nih.gov/Alzheimers/Publications/adfact.htm
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Alzheimer's Disease Education and Referral Center, National Institute on Aging
Dementia is a brain disorder that seriously affects a person's ability to carry out daily activities. The most common form of dementia among older people is Alzheimer's disease (AD), which involves the parts of the brain that control thought, memory, and language.