In a significant finding, Johns Hopkins researchers have revealed that those who feel sleepy during the day are nearly three times more likely to develop Alzheimer's disease than those who have a good night's sleep.

An analysis of data captured during a long-term study of ageing adults showed that those who report being very sleepy during the day were nearly three times more likely than those who didn't to have brain deposits of beta-amyloid -- a protein that's a hallmark for Alzheimer's disease -- years later.