Sleep Duration in Relation to Cognitive Function among Older Adults: A Systematic Review of Observational Studies

Observational studies of sleep duration and cognitive function in older adults have produced mixed results, with more studies suggesting that long (rather than short) sleep durations are related to worse cognition. Studies more consistently indicate that greater changes in sleep duration are associated with poor cognition. Future studies should be prospectively designed, with objective sleep assessment and longer follow-up periods; intervention studies are also needed to identify strategies for promoting cognitive health with aging.