The study, by a team led by Oxford University scientists, assessed the sleep habits of 147 adults aged 20-84 and took two MRI scans three and a half years apart. The team found that the 35% of the group that had poor sleep quality also had a reduced volume within the major brain regions of frontal, temporal and parietal areas. Those over the age of 60 had the most pronounced results.
This finding doesn’t definitively mean sleep deprivation or having trouble falling asleep causes brains to shrink, though. In fact, it could be the other way around, according to study author Claire Sexton from FMRIB.