Association between sleep patterns and depression in older adults: a cross-sectional study using data from the National Health and Nutrition Examination Survey 2007-2014.

Objective: To assess the association between sleep patterns and sleep factors (sleep duration, trouble sleeping, sleep disorder) and the risk of depression in older adults.

Methods: A total of 5636 participants (2754 men and 2882 women) aged 60 years and older from the 2007-2014 waves of the National Health and Nutrition Examination Survey (NHANES) were included. Sleep duration, sleep problems, and sleep disorders were assessed in the home by trained interviewers using the Computer-Assisted Personal Interviewing (CAPI) system. The combined sleep behaviours were referred to as 'sleep patterns (healthy, intermediate and poor)', with a 'healthy sleep pattern' defined as sleeping 7-9 h per night with no self-reported trouble sleeping or sleep disorders. Intermediate and poor sleep patterns indicated 1 and 2-3 sleep problems, respectively. Baseline characteristics of participants analysed using one-way logistic regression. Logistic multiple linear regression was used to assess the association of sleep factors and sleep patterns with the risk of depressive symptoms.Conduct subgroup analyses to ensure robustness of findings.

Results: The overall prevalence of depression was 7.7% among the 5636 participants analysed, with the rate of depression in older women being 1.6 times higher than in older men. The prevalence of depression was higher in older adults with intermediate sleep pattern than in older adults with healthy sleep pattern (OR: 2.28, 95% CI: 1.71-3.03, p < 0.001). The prevalence of depression was higher in older adults with poor sleep pattern than in older adults with healthy sleep pattern (OR: 5.60, 95% CI: 4.25-7.39, p < 0.001). The findings were robust after controlling for sleep items in the PHQ-9.

Conclusion: This nationally representative survey showed a relationship between sleep patterns and depression in older adults. However, the study population was limited to Americans, and we recommend continued investigation of the causal relationship and mechanisms between the two in the future, and further expansion of data sources in order to assess the applicability of the findings.