Separate and joint associations of adverse childhood experiences and childhood socioeconomic status with depressive symptoms: The mediating role of unhealthy lifestyle factors.

Background: The associations between adverse childhood experiences (ACEs), childhood socioeconomic status (SES), and depressive symptoms (DS) remain unclear. This study aimed to assess the separate and joint associations of ACEs and childhood SES with DS and explore the potential mediating role of lifestyles.

Methods: Data were obtained from the China Health and Retirement Longitudinal Study, which included 6879 participants. Cox proportional hazard models were used to evaluate the associations of ACEs and childhood SES with DS. Additive and multiplicative interactions between ACEs and childhood SES on DS were also examined. Causal mediation analyses were then conducted to quantify the mediating role of lifestyle factors in these associations.

Results: During a median follow-up of 3.0 years, 1283 (18.7 %) participants were identified with DS. ACEs and low childhood SES were significantly associated with an increased risk of DS (ACEs [3 or more vs 0]: HR = 1.68, 95 % CI: 1.43-1.99; childhood SES [low vs high]: HR = 1.48, 95 % CI: 1.22-1.79). Compared to the no ACEs-moderate/high childhood SES group, the group with 1 or more ACEs-low childhood SES had the highest risk of DS (HR = 1.76, 95 % CI: 1.47-2.10). Significant additive interaction of ACEs with low childhood SES on DS was observed with relative excess risk due to an interaction of 1.21 (95 % CI: 0.27, 2.15). Sleep duration and smoking were identified as the potentially modifiable mediators.

Conclusions: The findings highlight the importance of promoting initiatives to address ACEs, low childhood SES, and unhealthy lifestyles as part of DS prevention strategies.