Paternity leave duration and maternal depressive symptoms: a longitudinal study of paternal involvement and coparenting in Japan.

Background: Paternity leave may be associated with maternal mental health through fathers' involvement and coparenting, but short-term family-process associations during the early postpartum period remain unclear. Objective: We examined modeled structural and indirect associations among paternity leave duration, mother-reported paternal involvement and coparenting, and maternal depressive symptoms from 3 to 6 months postpartum, separately by parity. Methods: This two-wave online survey included 396 Japanese mothers (244 primiparas and 152 multiparas). At the 6-month follow-up, mothers reported the father's total paternity leave duration, categorized as no leave, short leave (1-31 days), or long leave (32 days or more). Paternal involvement at 3 and 6 months was modeled as a latent construct indicated by four domains of childcare and housework; coparenting and depressive symptoms were assessed using the CRS-J and CES-D, respectively. A multigroup two-wave structural equation model of structural and indirect associations was estimated. Indirect associations were evaluated using 5,000 bootstrap samples and bias-corrected 95% confidence intervals. All principal variables were mother-reported. Results: The freely estimated multigroup model showed good fit, χ Conclusion: Long paternity leave was associated with greater mother-reported paternal involvement and short-term coparenting continuity. The modeled indirect association with maternal depressive symptoms was very small, and formal comparisons did not establish parity differences. These findings describe short-term observational associations rather than causal effects.