Associations of Sleep Quality with Cognitive Function in Chinese Older Adults: The Roles of Self-Efficacy and Depressive Symptoms

Objective: To examine the associations among sleep quality, self-efficacy, depressive symptoms, and cognitive function in older adults, and to explore whether self-efficacy may be involved in the association between sleep quality and cognitive function and whether depressive symptoms may moderate this association. Methods: A cross-sectional survey was conducted among 2,030 older adults in Ningxia, China. Sleep quality, cognitive function, self-efficacy, and depressive symptoms were assessed using validated instruments. After adjusting for age, gender, marital status, education level, residence, smoking and drinking status, living alone, exercise, hypertension, diabetes, and coronary heart disease, mediation and moderated mediation analyses were performed using the PROCESS macro. Results: Significant correlations were observed among sleep quality, self-efficacy, depressive symptoms, and cognitive function. Self-efficacy showed a significant indirect effect in the association between sleep quality and cognitive function (B = − 0.034, 95% CI: − 0.048 to − 0.022). In addition, depressive symptoms significantly moderated the association between self-efficacy and cognitive function (B = 0.009, p < 0.01). The magnitude of the indirect association between sleep quality and cognitive function through self-efficacy was stronger at higher levels of depressive symptoms. Conclusion: Poor sleep quality was associated with poorer cognitive function in older adults, and self-efficacy may be involved in this association. Depressive symptoms may further strengthen this indirect association. These findings suggest that sleep quality, self-efficacy, and depressive symptoms may all be relevant to cognitive health among older adults. Plain Language Summary: Memory and thinking problems become more common with age. Poor sleep is also common in older adults and may be linked to worse brain health. However, less is known about the emotional and psychological factors that may be involved in this relationship. We carried out this study to better understand how sleep quality, confidence in handling daily challenges, and depressive symptoms are related to cognitive function in older adults. We studied 2,030 older adults in Ningxia, China. We collected information on their sleep quality, depressive symptoms, and self-efficacy, which refers to a person’s confidence in managing problems and daily tasks. We also assessed cognitive function, including memory and other thinking abilities. We then examined how these factors were related to one another. We found that older adults with poorer sleep quality tended to have lower cognitive function. Poorer sleep was also linked to lower self-efficacy, and lower self-efficacy was linked to poorer cognitive function. In addition, depressive symptoms were related to a stronger negative relationship between self-efficacy and cognitive function. These findings suggest that sleep, mood, and confidence in daily self-management may all be important for cognitive health in older adults. This does not prove cause and effect, but it highlights several factors that may be useful for future prevention and support. Efforts to improve sleep and support emotional well-being may help promote healthy cognitive aging. Keywords: sleep quality, cognitive function, self-efficacy, depressive symptoms, older adults, moderated mediation