What comes first: Postpartum depression or low mother-to-infant bonding? A cross-lagged analysis in a low-risk...

Longitudinal evidence on the direction of the association between postpartum depression (PPD) and mother-to-infant bonding (MIB) remains mixed and is largely based on high-income countries. We investigated the bidirectional associations between PPD symptoms and MIB in a low-risk Brazilian sample during the first year postpartum. One hundred mothers from the São Paulo metropolitan area (32 ± 5.9 years) were assessed at three time points during the first year postpartum (T1: 6 months, T2: 10 months, and T3: 12 months). Mothers completed a Structured Questionnaire (T1), the Edinburgh Postnatal Depression Scale (EPDS) and the Maternal Postnatal Attachment Scale (MPAS) at T1, T2, and T3. Using cross-lagged panel models, adjusted for eight individual and contextual covariates, we found three main results. First, PPD and MIB were negatively correlated at each time point, significantly at T1 and T3. Second, higher PPD symptoms predicted lower subsequent MIB (β = -0.15, p = .02 for T1 → T2; β = -0.14, p = .02 for T2 → T3), whereas MIB did not predict later PPD. Third, the negative cross-lagged association between PPD and MIB remained significant after adjustment, indicating a consistent effect across time. These results highlight the potential of maternal depressive symptoms to disrupt mother-infant bonding even in a low-risk context. Early detection and treatment of postpartum depression may therefore help foster healthy mother-infant relationships.