Cumulative childhood adversity and depressive symptoms in middle-aged and older adults: the moderating role of sleep duration in a longitudinal study of CHARLS

Childhood adversity is associated with depression across the life course, while sleep duration may influence vulnerability to depressive symptoms. However, whether sleep duration modifies the association between cumulative childhood adversity and later-life depressive symptoms remains unclear. Data from 9,118 adults aged ≥ 45 years in the China Health and Retirement Longitudinal Study (CHARLS) were analyzed. A cumulative childhood adversity score (CAS) was constructed from eight early-life adversity indicators. Depressive symptoms were assessed using the 10-item Center for Epidemiologic Studies Depression Scale (CES-D-10) in 2013 and 2020. Multivariable logistic regression, restricted cubic spline analyses, and sensitivity analyses were performed. Interactions between CAS and nighttime sleep duration measured in 2020 and 2013 were examined separately. Each one-point increase in CAS was associated with higher odds of depressive symptoms in 2020 after adjustment for baseline depressive symptoms and other covariates (OR = 1.238, 95% CI: 1.191–1.287). A graded, approximately linear association was observed. Short nighttime sleep duration (< 6 h) was associated with higher odds of depressive symptoms compared with normal sleep duration (OR = 2.021, 95% CI: 1.832–2.231). Nighttime sleep duration measured in 2020 significantly modified the CAS–depressive symptoms association (interaction OR = 0.967, 95% CI: 0.947–0.988; P = 0.002), with weaker associations at longer sleep durations. However, the corresponding interaction using sleep duration measured in 2013 was not statistically significant ( P = 0.488). Cumulative childhood adversity was associated with higher odds of depressive symptoms among middle-aged and older Chinese adults. Nighttime sleep duration modified this association when measured concurrently with depressive symptoms, but not prospectively. Further studies are needed to clarify the temporal relationship and potential protective role of sleep health.