The New York Times reports:

Could getting too little sleep increase your chances of developing dementia?

For years, researchers have pondered this and other questions about how sleep relates to cognitive decline. Answers have been elusive because it is hard to know if insufficient sleep is a symptom of the brain changes that underlie dementia — or if it can actually help cause those changes.

Now, a large new study reports some of the most persuasive findings yet to suggest that people who don’t get enough sleep in their 50s and 60s may be more likely to develop dementia when they are older.

The research, published Tuesday in the journal Nature Communications, has limitations but also several strengths. It followed nearly 8,000 people in Britain for about 25 years, beginning when they were 50 years old. It found that those who consistently reported sleeping six hours or less on an average weeknight were about 30 percent more likely than people who regularly got seven hours sleep (defined as “normal” sleep in the study) to be diagnosed with dementia nearly three decades later. [Continue reading…]