Abstract

There are approximately one hundred forms of dementing illness, but Alzheimer’s disease (AD) is the most prevalent type, accounting for over 60 percent of all cases. The risk of symptomatic AD increases with age. Today it affects an estimated 5.4 million people in the U.S. and 432,000 in the U.K. Worldwide, the prevalence of all forms of dementia is over 24 million people. In 2050 there will be an estimated 11–16 million people with AD in the U.S., and the cost of their care will exceed $1.1 trillion (Alzheimer’s Association 2012: 13–21; Nuffield Council on Bioethics 2009: 4–6).