A Stress Process Model of Postpartum Depressive Symptoms Among Thai Mothers: A Structural Equation Modeling Approach.

Background/Objectives: Postpartum depressive symptoms are a major maternal mental health concern associated with adverse outcomes for mothers and infants. Although biological, psychological, and social factors have been associated with postpartum depressive symptoms, limited evidence has examined their interrelationships within a theoretically grounded framework among Thai mothers. This study aimed to test a hypothesized Stress Process Model of factors associated with postpartum depressive symptoms among Thai mothers using structural equation modeling (SEM). Methods: A cross-sectional study was conducted among 462 Thai mothers attending routine 4-6-week postnatal follow-up clinics at three tertiary hospitals in Northern Thailand. Participants were recruited using proportional allocation and consecutive sampling. Data were collected between April and June 2025 using standardized measures of postpartum depressive symptoms and standardized measures of self-perceived burden, parenting stress, social support, self-esteem, mastery, and coping, together with demographic and clinical data. Data were analyzed using descriptive statistics and SEM. Results: Using the prespecified Edinburgh Postnatal Depression Scale cutoff score of ≥11, 30.95% of participants screened positive for probable postpartum depressive symptoms. The final structural model demonstrated acceptable fit to the data (χ2/df = 2.95, RMSEA = 0.07, CFI = 0.94, TLI = 0.92, and SRMR = 0.05) and explained 65.10% of the variance in postpartum depressive symptoms. Self-perceived burden and parenting stress showed significant positive direct associations with postpartum depressive symptoms, whereas social support showed significant inverse direct and indirect associations. Perinatal complications were directly associated with postpartum depressive symptoms and indirectly associated through self-perceived burden and parenting stress. Mastery also showed a significant inverse indirect association. Conclusions: The findings support theoretically specified associations consistent with the Stress Process Model. Because all variables were assessed concurrently, the identified pathways should be interpreted as statistical associations rather than evidence of temporal ordering or causal mechanisms.