Multiple Self-Reported Sleep Measures Are Differentially Associated With Cognitive Performance in Community-Dwelling Nondemented Elderly
Objective: To examine associations between daytime and insomnia-related sleep problems with different domains of cognitive functioning and determine whether subclinical depressive symptoms and age moderate these associations. Method: A total of 903 cognitively healthy older adults enrolled in a longitudinal aging study completed the UDS neuropsychological battery (measuring attention, executive functioning, episodic memory, language and processing speed). Subclinical depressive symptoms were also assessed and self-reported measures of sleep were administered. Results: Hierarchical multiple regression analyses separately assessing the effects of daytime and insomnia-related sleep problems on cognition identified relationships between both daytime and insomnia-related sleep problems with a composite measure of executive functioning; however, the former was related more to speed of processing and the latter to higher order executive abilities. Age moderated the relationship between insomnia severity and executive functioning, and subclinical depressive symptoms moderated the relationship between insomnia-related sleep problems and performance on measures of attention. Conclusions: Among older adults, sleep problems have a deleterious effect on executive functioning regardless of whether they occur during the day or nighttime; however, age and subclinical depressive symptoms differentially impact relationships between sleep variables and cognitive domains.