The incidence of dementia has been expected to substantially rise as the average life expectancy increased in high income countries. Surprisingly, two studies seem to contradict that expectation. One covering Europe shows that the rate of dementia there has stabilized, while the other study shows that the dementia rate in the US has been declining. Researchers have been unable to explain why this has been happening.
Links to articles on these studies, as well as the studies themselves, have been posted in Alzheimer’s > Epidemiology:
The article and research dealing with Europe are:
The article and research dealing with the US are: