Sleeping too little in middle age may increase dementia risk, study finds 20 Apr, 2021 10:46 PM 8 minutes to read A new study suggests that people who don't get enough sleep in their 50s and 60s may be more likely to develop dementia when they are older. Photo / 123RF A new study suggests that people who don't get enough sleep in their 50s and 60s may be more likely to develop dementia when they are older. Photo / 123RF New York Times By: Pam Belluck The research, tracking thousands of people from age 50 on, suggests those who sleep six hours or less a night are more likely to develop dementia in their late 70s.