Socioeconomic Structural Resources and Depressive Symptoms among Postpartum Women in China: Evidence of Rising Rural Depression Risk from a Repeated Cross-Sectional Study Using CFPS 2016-2022

Abstract Background Using four waves (2016–2022) of nationally representative data from the China Family Panel Studies (CFPS), this study examined the association between a composite structural resource index-comprising education and personal income-and postpartum depressive symptoms, and focus on temporal and urban-rural differentials in depression risk over the study period. Methods The sample included 743 mothers of infants aged 0 years. Principal component analysis was used to construct a two-dimensional structural resource index. Depressive symptomatology was assessed using the Center for Epidemiologic Studies Depression Scale (CES-D), with a cut-off of ≧ 36 indicating depression positivity. Linear and logistic regression models were fitted with adjustment for confounders. Stratified analyses by urban/rural residence and educational level were performed, along with two robustness checks. Results Each one-unit increase in the structural resource index was associated with a 20.4% lower odds of depression positivity (OR = 0.796, 95% CI: 0.670–0.944, P = 0.009). Notably, the odds of depression positivity among rural postpartum women increased three-fold from 2016 to 2022, whereas no significant temporal change was observed among their urban counterparts. Sensitivity analyses confirmed the stability of these findings. Conclusions Structural resources-education and income-are consistently and inversely associated with postpartum depressive symptoms. The escalating depression risk among rural mothers over the 2016–2022 period highlights a persistent structural mental health inequality between urban and rural areas. Targeted psychological interventions for low-educated, rural postpartum women are needed to narrow the perinatal mental health gap.