The association between water source and depressive symptoms in China: A cross-sectional and longitudinal study

Income inequality, trust, and depressive symptoms among Chinese adults (CFPS): A causal mediation analysis

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

LIMITATION

This study didn't deal with the impact of post-treatment confounders of the mediator-outcome relationship.

CONCLUSIONS

Severe income inequality directly and indirectly exacerbated depressive symptoms. Government should carry out the implementation of decreasing income inequality and improving trust.

Income inequality and depressive symptoms among Chinese adults: a quasi-experimental study

OBJECTIVE

There is a lack of causal evidence on the impact of income inequality on depressive symptoms. The impact of China's Targeted Poverty Alleviation (TPA) policy on depressive symptoms is also unclear. Using a quasi-experimental design, this study aims to investigate the causal effects of TPA and income inequality on depressive symptoms among Chinese adults.

STUDY DESIGN

This is a population-based study.

METHODS

Three waves (2012, 2016, and 2018) of the China Family Panel Studies (CFPS), a nationally representative sample of China, were included in this study. We performed difference-in-difference (DID) models to assess the effect of TPA and income inequality on depressive symptoms. We further conducted the mixed effect models to examine the impact of income inequality on depressive symptoms. The study considered a range of spatial factors and spatial splines to address spatial autocorrelations.

RESULTS

This study included valid measures of depressive symptoms (Center for Epidemiologic Studies Depression Scale [CES-D-8] score) from 14,442 adults of CFPS. The DID results indicated that at the provincial level, the CES-D-8 score of the TPA treatment group was on average 0.570 (95% confidence interval [CI]: 0.358-0.783) less than the control group. Furthermore, a 0.1 increase in Gini index would lead to a 0.256 (95% CI: 0.064-0.448) increase in CES-D-8 score. The mixed effect model showed that income inequality was a risk factor for depressive symptoms at the provincial level (excess risk = 5.602% [95% CI: 3.047%-8.219%]).

CONCLUSIONS

Our findings suggest that income inequality adversely affects mental health, but China's Targeted Poverty Alleviation improves the mental health of the Chinese population.

Internal Migration Experience and Depressive Symptoms among Middle-Aged and Older Adults: Evidence from China

Background: This study aimed to examine the association of internal migration experience with depressive symptoms among middle-aged and elderly Chinese, as well as explore possible mechanisms of the relationship. Methods: Participants were from the China Health and Retirement Longitudinal Study (CHARLS), a nationally representative sample of residents aged 45 years and older (n = 43,854). Survey data on depressive symptoms and internal migration experience were collected from biennial CHARLS surveys (CHARLS 2011/2013/2015) and a unique CHARLS life history survey in 2014, respectively. Multiple logistic regressions and the Karlson–Holm–Breen (KHB) method were employed in the statistical analyses. Results: The overall prevalence rate of depressive symptoms among middle-aged and older adults was 34.6%. Internal migration experience was associated with higher risks of depressive symptoms (OR = 1.07, 95% CI = 1.02–1.12, p < 0.01), especially among females (OR = 1.08, 95% CI = 1.01–1.14, p < 0.05), middle-aged adults (OR = 1.12, 95% CI = 1.06–1.19, p < 0.001), rural-to-urban migrants who had not obtained an urban hukou (OR = 1.13, 95% CI = 1.07–1.19, p < 0.001), and those who had low migration frequency and first migrated out at 35 years of age or older. Chronic disease (17.98%, p < 0.001), physical injury (7.04%, p < 0.001), medical expenditure (7.98%, p < 0.001), pension insurance (4.91%, p < 0.001), and parent–child interaction (4.45%, p < 0.01) were shown to mediate the association of internal migration experience with depressive symptoms. Conclusions: This study indicates that there is a significant association between internal migration experience and high risks of depression onset later in life. It is suggested to reduce institutional barriers for migrants and implement evidence-based interventions to improve migrants’ mental health.