Abstract
BACKGROUND: The link between sleep onset time and depression is not well understood. We aimed to investigate the association of sleep onset time with depression. METHODS: Data from the 2015 to March 2020 National Health and Nutrition Examination Survey were analyzed. Sleep onset time was categorized into five intervals: [22:00-23:00), [23:00-00:00), [00:00-01:00), [01:00-20:00), and [20:00-22:00). Depression was assessed using the Patient Health Questionnaire. Multivariate logistic regression and generalized linear regression analyses were conducted to evaluate the association of sleep onset time with depression. RESULTS: The study sample consisted of 6991 adults (weighted mean age 45.6 years [SE, 0.5]; 49.5% female). Depression prevalence varied by sleep onset time intervals: 4.12% for [00:00-01:00), 5.94% for [01:00-20:00), 3.89% for [20:00-22:00), 1.98% for [22:00-23:00), and 3.26% for [23:00-00:00). After adjusting for sleep duration and other covariates, the odds ratios (ORs) for depressive symptoms were significantly greater at sleep onset time during [01:00-20:00) (OR, 2.39; 95% CI 1.20-4.74) and marginally higher at [20:00-22:00) (OR, 1.78; 95% CI 0.99-3.20) compared to the sleep onset time during [22:00-23:00). Higher PHQ-9 scores were associated with sleep onset time outside [22:00-23:00). CONCLUSION: Sleep onset time between [22:00-23:00) was associated with the lowest odds of depression. This suggests new directions for depression research and interventions, emphasizing the importance of considering sleep onset time in mental health strategies.