Sleep disturbance mediates the relationship between depressive symptoms and cognitive function in older adults with mild cognitive impairment.

This study examined whether and to what extent sleep disturbance mediates the effects of depressive symptoms on the cognition of individuals with mild cognitive impairment (MCI), who represent a high-risk group for developing dementia. Cross-sectional data were obtained from a sample of 204 Chinese community-dwelling older adults with MCI. MCI subjects were screened using the Montreal Cognitive Assessment, sleep quality was measured using the Pittsburgh Sleep Quality Index, and depressive symptoms were assessed using the Geriatric Depression Scale. Mediation analysis was conducted using the PROCESS macro with 10,000 bootstrap samples. The significant mediating effect of sleep quality on the association between depressive symptoms and cognition (Beta = -0.025; 95% CI, -0.054 to -0.007) explains 26% of the total effect of depressive symptoms on cognition and implies that the timely detection and management of sleep disturbance among the MCI population is highly important, especially for those with depressive symptoms.