Examining the Interaction Between Cognitive Reserve, Depression, and Sleep Quality: A Mixed-Method Study in an Aging Population

Abstract

Objectives: Poor sleep quality and disorders like insomnia are prevalent in the aging population. This mixed-methods study aimed to identify predictors of sleep quality. Methods: In an online survey, 152 participants aged 65–86 completed questionnaires assessing sleep quality (Pittsburgh Sleep Quality Index [PSQI]), depressive symptoms (Beck Depression Inventory [BDI]), and cognitive reserve (Cognitive Reserve Test [CoRe-T]), alongside a narrative about their sleep experiences. Results: Demographics, depression, and cognitive reserve (CR) explained 79.3% of the variance in sleep quality. Age and depression predicted poorer sleep, whereas CR was linked to better sleep quality. Depression moderated this effect, reducing CR’s protective role. Participants’ narratives explained an additional 5.1% of the variance, with negative emotional language predicting poorer sleep and a present or past focus linked to better sleep. Higher CR correlated with more positive emotions and less present focus. Discussion: Cognitive reserve protects against sleep problems, and subjective reports offer insight into sleep perception, beneficial for prevention and treatment strategies.