Complex associations of adverse childhood and adulthood experiences with incident depressive symptoms in middle-aged and older Chinese adults

The associations of adverse childhood experiences (ACEs) and adverse adulthood experiences (AAEs) with incident depressive symptoms remain incompletely understood. The study sought to explore the complex associations of ACEs and AAEs with incident depressive symptoms among middle-aged and older adults. Data of 4516 participants aged ≥ 45 years were sourced from the China Health and Retirement Longitudinal Study. Information on ACEs, AAEs, depressive symptoms, sociodemographic profiles, health behaviors, self-reported chronic diseases, retirement status, and adulthood social support was collected. Modified Poisson regression analysis, Karlson-Holm-Breen mediation analysis and interaction analysis were conducted. The overall numbers of ACEs (RR: 1.12; 95% CI: 1.08, 1.16) and AAEs (RR: 1.10; 95% CI: 1.06, 1.14) were independently associated with an increased risk of incident depressive symptoms. Significant dose-response relationships were detected between the numbers of ACEs (P-trend < 0.001) and AAEs (P-trend < 0.001) and the risk of incident depressive symptoms. The overall AAEs mediated 5.78% of the total effect of ACEs on incident depressive symptoms. No significant multiplicative (RR: 0.99; 95% CI: 0.77, 1.25) or additive [RERI (95% CI): 0.02 (-0.27, 0.30); AP (95% CI): 0.01 (-0.19, 0.21); SI (95% CI): 1.04 (0.49, 2.20)] interactions were detected between ACEs and AAEs on incident depressive symptoms. Both ACEs and AAEs were independently associated with an increased risk of incident depressive symptoms in a dose-response manner, with AAEs partially mediating the total effect of ACEs on incident depressive symptoms. These findings support preventive strategies targeting ACEs and AAEs to mitigate the risk of incident depressive symptoms in later adulthood.