Longer depressive duration reduces sleep duration more: A longitudinal study in the middle-aged and elderly Chinese

Quantifying the effect of depression on sleep duration is of great importance to the diagnosis, control, prevention of sleep-related diseases and understanding related biological mechanisms. However, existing studies explored the effect without considering depressive duration, which may cause inaccurate results.

Accessing the data from the China Health and Retirement Longitudinal Study in 2011, 2013, 2015 and 2018, we used the interval between two interviews with persistent depression status to approximate depressive duration. Five analysis subsamples with different depressive durations, i.e., 2, 3, 4, 5, 7 years, were obtained. The change amount of sleep duration between two interviews was used as the outcome variable. A multiple linear model was independently used to estimate the effect in each subsample, and meta-regression was used to test the trend. Subgroup analyses in terms of genders, ages and baseline sleep durations were performed.

On average, 2, 3, 4, 5, 7-years depressive durations significantly reduced sleep duration by 0.46, 0.57, 0.72, 0.75, 1.07 h (P < 0.001), respectively. Especially for the elderly, female, and participants with normal baseline sleep duration, the reduction was larger. Trend test showed that the variation trend was significant (P < 0.001). Similar results were found in the subgroup analyses.

Sleep duration and depression are not measured by gold-standard methods.

Depression significantly reduces sleep duration, especially for the elderly, female, and people with normal baseline sleep duration. Longer depressive duration reduces sleep duration more. Such finding provides more detailed epidemiological evidence for depression-sleep relationship.