State Key Laboratory of Molecular Vaccine and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen, China; Key Laboratory of Health Technology Assessment of Fujian Province, School of Public Health, Xiamen University, Xiamen, China.
State Key Laboratory of Molecular Vaccine and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen, China; Key Laboratory of Health Technology Assessment of Fujian Province, School of Public Health, Xiamen University, Xiamen, China; National Institute for Data Science in Health and Medicine, Xiamen University, Xiamen, China.
J Affect Disord. 2025 Jan 15;369:696-705. doi: 10.1016/j.jad.2024.10.003. Epub 2024 Oct 3.
Income inequality has been linked to depressive disorders, but the pathways behind this impact are insufficiently understood. Hence, we aimed to investigate the impact of income inequality on depressive disorders and evaluate the extent to which this impact is mediated by trust.
Two waves (2012 and 2018) of the China Family Panel Studies (CFPS) were included. Depressive symptoms were assessed using the 8-item Center for Epidemiologic Studies Depression scale (CESD8) and income inequality was measured using the Gini index calculated with household income. Based on the counterfactual framework, causal mediation analysis was applied with the difference-in-difference (DID) method. The sequential ignorability assumption, an important assumption for mediation analysis, was examined by propensity score matching (PSM) and simulation-based sensitivity analysis.
Compared to the control group (Change of Gini index ≤0), CESD8 scores in the treatment group (Change of Gini index >0) increase by 0.233 (95 % CI: 0.039, 0.430), which 10.1 % (95 % CI: 3.1 %, 46.0 %) was mediated by reductions in trusts at the provincial level. At the county level, income inequality influences depressive symptoms through the indirect path (β=0.008, 95%CI: 0.001, 0.020) instead of the direct path (β= - 0.146, 95%CI: -0.287, 0.000). Dividing the trust, the significant indirect effect appeared in the trust in neighbors, foreigners, government, and doctors at the provincial level.
This study didn't deal with the impact of post-treatment confounders of the mediator-outcome relationship.
Severe income inequality directly and indirectly exacerbated depressive symptoms. Government should carry out the implementation of decreasing income inequality and improving trust.
收入不平等与抑郁障碍有关，但人们对这种影响的作用途径了解不足。因此，我们旨在研究收入不平等对抑郁障碍的影响，并评估信任在其中的中介作用程度。
本研究纳入了中国家庭追踪调查（CFPS）的两个波次（2012 年和 2018 年）。抑郁症状采用 8 项中心流行病学研究抑郁量表（CESD8）评估，收入不平等采用家庭收入计算的基尼指数衡量。基于反事实框架，采用差值法（DID）进行因果中介分析。通过倾向评分匹配（PSM）和基于模拟的敏感性分析检验中介分析的重要假设——顺序可忽略性假设。
与对照组（基尼指数变化≤0）相比，治疗组（基尼指数变化>0）的 CESD8 评分增加了 0.233（95%置信区间：0.039，0.430），其中 10.1%（95%置信区间：3.1%，46.0%）是通过省级信任水平下降介导的。在县级层面，收入不平等通过间接路径（β=0.008，95%置信区间：0.001，0.020）而不是直接路径（β=-0.146，95%置信区间：-0.287，0.000）影响抑郁症状。在信任方面，省级层面的邻里信任、外国信任、政府信任和医生信任的间接效应显著。
本研究未涉及中介-结局关系中治疗后混杂因素的影响。
严重的收入不平等直接和间接加剧了抑郁症状。政府应实施减少收入不平等和提高信任的措施。
