How common is dementia among seniors?
Estimates vary, and exact numbers are hard to come by. But an often quoted statistic is that the incidence of dementia doubles every five years beginning at age 60. It is estimated that dementia affects 1 percent of those aged 60 to 64, 20 percent of those over 80 and more than 30 percent of those over age 85. Still other estimates, including those based on the 1989 Harvard Alzheimer’s study, place the rate of dementia in people over 85 closer to 50 percent.
Whatever the actual percentages, the total number of seniors with dementia is likely to increase, since the over-65 population of the United States is expected to double by 2025.