EXCESSIVE DAYTIME SLEEPINESS AND COGNITION
A large epidemiological longitudinal study of older men (mean age of 76.6 years, range 71 to 93) investigated the association between sleep disturbances (insomnia and daytime sleepiness) and the incidence of dementia and cognitive decline.34 It was found that there was a significant association between the self-report of excessive daytime sleepiness and the diagnosis of incident dementia three years later. The risk was twofold as compared to those not reporting daytime sleepiness, after adjusting for age and other factors. Incident cognitive decline also was significantly associated with excessive daytime sleepiness. In contrast, insomnia was not associated with either incident cognitive decline or dementia.