ABSTRACT
Sleep disturbances are common in older adults and particularly affect those with cognitive impairment. Meanwhile, growing evidence from epidemiologic studies suggests that sleep disturbances, particularly extreme sleep duration, insomnia, sleep fragmentation, sleep-disordered breathing and excessive daytime sleepiness could also contribute to an increased risk of dementia in cognitively normal adults. More studies are needed to examine circadian rhythm dysfunction and to better characterize sleep using objective measures. A number of biological mechanisms linking sleep and cognition have been proposed, including amyloid-β accumulation, neuroinflammation and vascular and neurotransmitter changes. However, the exact mechanisms are still poorly understood and remain to be elucidated. Treatment trials are required to examine whether intervention of sleep could help to improve cognition and delay or prevent dementia onset.
