Sleep and Depressive Symptoms in Sedentary Community-Dwelling Older Adults With Sleep Complaints: Findings From Ambulatory Sleep EEG.

Background: There is limited and inconsistent evidence on the association between electroencephalography (EEG) measured sleep and depressive symptoms among community-dwelling older adults. This study aimed to investigate the cross-sectional association between EEG-measured sleep and depressive symptoms.

Methods: Using baseline data from a randomized clinical trial, we included 66 sedentary community-dwelling older adults with sleep complaints (≥ 1 self-reported insomnia symptom). Sleep was measured using an in-home sleep EEG (Sleep Profiler™) for 2 nights and the Geriatric Depression Scale (GDS-15) was used to measure depressive symptoms. Multiple linear regression analyses were conducted with each sleep parameter as the primary predictor and GDS score as the outcome, adjusting for age, sex, race, education, marital status, chronic conditions, and Montreal Cognitive Assessment (MoCA) score.

Results: Several sleep variables were associated with depressive symptoms (GDS score), including a higher percentage of sleep stage N1 (B = 0.11, 95% confidence interval [CI]: 0.02 - 0.20) and N2 (B = 0.04, 95% CI: 0.00 - 0.08), a lower percentage of N3 sleep (B = -0.04, 95% CI: -0.08 to -0.01), greater wake after sleep onset (B = 0.01, 95% CI: 0.00 - 0.02), and a greater number of awakenings ≥90s/hour (B = 0.87, 95% CI: 0.21-1.53).

Conclusions: Our study reveals that among sedentary community-dwelling older adults with sleep complaints, more lighter sleep (stage N1, N2), less deep (N3) sleep, and increased awakenings are associated with more depressive symptoms. Sleep interventions aimed at enhancing sleep architecture may also help alleviate depressive symptoms in this population.