Is it a kind of Flynn effect for the elderly?:
Dementia is actually on the wane. And when people do get dementia, they get it at older and older ages.
Previous studies found the same trend but involved much smaller and less diverse populations like the mostly white population of Framingham, Mass., and residents of a few areas in England and Wales.
The new study found that the dementia rate in Americans 65 and older fell by 24 percent over 12 years, to 8.8 percent in 2012 from 11.6 percent in 2000. That trend that is “statistically significant and impressive,” said Samuel Preston, a demographer at the University of Pennsylvania who was not associated with the study.
In 2000, people received a diagnosis of dementia at an average age of 80.7; in 2012, the average age was 82.
“The dementia rate is not immutable,” said Dr. Richard Hodes, director of the National Institute on Aging. “It can change.”
And that “is very good news,” said John Haaga, director of the institute’s division of behavioral and social research. It means, he said, that “roughly a million and a half people aged 65 and older who do not have dementia now would have had it if the rate in 2000 had been in place.”
That is from Gina Kolata from the NYT. The piece has many other points of interest.