Postpartum maternal depression, mother-to-infant bonding, and their association with child difficulties in sixth grade.

Objective: Postpartum maternal mental health plays a crucial role in the development of children's social and emotional competencies. This study aimed to investigate the influence of postpartum maternal depression and mother-to-infant bonding on children's emotional and behavioral difficulties in sixth grade.

Methods: Data from the maternal Edinburgh Postnatal Depression Scale (EPDS) and the Mother-to-Infant Bonding Scale-Japanese version (MIBS-J), administered to mothers approximately 2 weeks to 1 month postpartum during postnatal health checkups in Okaya, Japan, were analyzed alongside Strengths and Difficulties Questionnaire (SDQ) data collected from their sixth-grade children and their caregivers. The study included 245 mother-child pairs of children born between April 2, 2009, and April 1, 2012.

Results: Postpartum maternal depressive symptoms, as assessed by the EPDS, were significantly associated with mother-to-infant bonding difficulties, as assessed by the MIBS-J. Structural equation modeling revealed that EPDS, MIBS-J, and sex significantly predicted psychosocial difficulties of children. Bonding difficulties mediated 34.6% of the total effect of EPDS on child difficulties. The models explained 26.1% of the variance in psychosocial difficulties, with 43.0% of the variance explained for parent-rated SDQ scores and 36.4% for self-rated SDQ scores.

Conclusions: The negative impact of maternal depressive symptoms on mother-to-infant bonding may have contributed to increased difficulties for the child, highlighting the critical role of bonding in moderating the effects of maternal mental health on child development. These findings underscore the importance of early postpartum interventions targeting both maternal depression and bonding difficulties to mitigate long-term effects on child development.