Differences in postpartum depressive symptoms across survey waves among Chinese mothers and their association with structural resources: a repeated cross-sectional study based on CFPS data

Objective Using China Family Panel Studies data (CFPS; 2016, 2018, 2020, and 2022), this study examined between-sample differences in postpartum depressive symptoms across survey waves in China and their association with structural resources. Methods This repeated cross-sectional study included 827 mothers living in households with 0-year-old infants, identified by linking child questionnaires, family relationship files, and adult questionnaires. Depressive symptoms were measured using the CES-D total score. Elevated depressive symptoms were defined as CES-D ≥ 36, approximately corresponding to the conventional CES-D ≥ 16 cutoff. Structural resources were measured using an index based on educational attainment, employment status, and urban–rural residence. Descriptive statistics, multiple linear regression, binary logistic regression, and sensitivity analyses were conducted. Results Mean CES-D scores across the four survey-wave samples were 32.1 ± 7.0, 32.8 ± 6.3, 32.8 ± 7.7, and 34.2 ± 8.4. The proportions with elevated depressive symptoms were 25.3, 28.5, 27.4, and 31.4%. In fully adjusted models, the 2022 sample had higher CES-D scores ( β = 3.02, SE = 0.99, p = 0.002) and higher odds of elevated depressive symptoms (OR = 2.56, 95% CI: 1.33–4.92, p = 0.005) than the 2016 sample. The structural resource index was negatively associated with elevated depressive symptoms (OR = 0.88, 95% CI: 0.77–1.00, p = 0.046), but this association was attenuated under a stricter threshold. Conclusion Postpartum depressive symptoms differed across CFPS survey-wave samples. Higher structural resources were modestly associated with lower odds of elevated depressive symptoms.