Summary: A new longitudinal study from Shinshu University highlights how postpartum maternal depression and early mother-to-infant bonding influence a child’s emotional and behavioral development into middle childhood. The research shows that strong early bonding can substantially lessen the negative effects of postpartum depression on later psychosocial outcomes.
In a cohort of 245 mother–child pairs, researchers found that postpartum depressive symptoms in mothers predicted higher rates of emotional and behavioral difficulties by sixth grade. Importantly, secure mother-to-infant bonding mediated roughly 34.6% of this association, indicating that improving early bonding may reduce long-term child difficulties even when mothers experience postpartum depression.
Key Facts:
- Bonding as a mediator: Mother-to-infant bonding explained about 34.6% of the connection between postpartum depression and later child difficulties.
- Persistent effects: Children of mothers with postpartum depressive symptoms showed greater emotional and behavioral problems in sixth grade.
- Sex differences: Boys were more likely than girls to exhibit psychosocial difficulties, especially in conduct issues and attention/hyperactivity domains.
Source: Shinshu University
Background: Maternal mental health and the quality of early mother-to-infant bonding are established determinants of a child’s social and emotional development. Infants of mothers who experience postpartum depression often show more variable temperaments and may encounter delays in cognitive and socioemotional milestones. Maternal depressive symptoms can also interfere with the bonding process, heightening the risk of insecure attachment and later developmental challenges.
Although previous research has documented short-term effects of postpartum depression and bonding problems on infant development, fewer studies have examined how these early maternal factors jointly affect psychosocial and behavioral outcomes in middle childhood. To fill this gap, researchers at Shinshu University conducted a longitudinal analysis focused on sixth-grade outcomes.
Led by Associate Professor Daimei Sasayama (Department of Psychiatry) and Professor Hideo Honda (Department of Child and Adolescent Developmental Psychiatry), the team tested whether mother-to-infant bonding mediates the long-term influence of postpartum depression on child mental health. Their results were published in Archives of Women’s Mental Health on April 15, 2025.
The study followed 245 mother–child pairs from Okaya, Japan, including children born between April 2, 2009, and April 1, 2012. Researchers used validated screening tools: the Edinburgh Postnatal Depression Scale (EPDS) for maternal depressive symptoms, and the Mother-to-Infant Bonding Scale—Japanese version (MIBS-J) to assess early bonding. Child outcomes were measured with the Japanese version of the Strengths and Difficulties Questionnaire (SDQ), collected from both sixth-grade students and their caregivers.
EPDS and MIBS-J assessments were completed by mothers roughly two weeks to one month after delivery during routine postnatal health checkups. Sixth-grade SDQ reports included self-assessments from children and parent/caregiver ratings; among parent raters, 92.2% were mothers, 7.3% fathers, and one respondent was another caregiver.
Approximately 17.1% of mothers in the sample screened positive for postpartum depressive symptoms, a prevalence consistent with national estimates in Japan. Statistical modeling revealed both direct effects of maternal postpartum depressive symptoms on later child difficulties and indirect effects operating through impaired mother-to-infant bonding.
Dr. Sasayama explains, “Mother-to-infant bonding mediated 34.6% of the impact of postpartum depression on child difficulties, confirming our hypothesis that early bonding can buffer some long-term negative outcomes.” The analysis also identified child sex as a significant predictor of psychosocial outcomes: boys showed higher overall difficulty scores than girls, particularly in conduct problems and hyperactivity/inattention.
Both self- and parent-rated SDQ scores indicated that children of mothers with postpartum depressive symptoms experienced greater challenges. These results emphasize the enduring importance of early mother–child attachment and suggest that strengthening bonding during the postpartum period may reduce the trajectory toward later psychosocial difficulties.
The authors recommend early interventions that support bonding among mothers with postpartum depression to promote healthier developmental outcomes. Future research should investigate which specific depressive symptoms most disrupt bonding, include broader samples, and examine additional contributors such as genetic factors and socioeconomic conditions to inform targeted prevention and treatment strategies.
About this neurodevelopment and PPD research news
Author: Chinatsu Anthoine
Source: Shinshu University
Contact: Chinatsu Anthoine, Shinshu University
Image: Image credited to Neuroscience News
Original Research: Open access. “Postpartum maternal depression, mother-to-infant bonding, and their association with child difficulties in sixth grade” by Daimei Sasayama et al., Archives of Women’s Mental Health.
Abstract
Postpartum maternal depression, mother-to-infant bonding, and their association with child difficulties in sixth grade
Purpose
This study examined how postpartum maternal depression and early mother-to-infant bonding influence children’s emotional and behavioral difficulties by sixth grade. The research aimed to determine whether bonding mediates the long-term effects of maternal depressive symptoms on child psychosocial outcomes.
Methods
Researchers analyzed EPDS and MIBS-J data gathered from mothers approximately two weeks to one month postpartum during routine health checkups in Okaya, Japan, alongside SDQ assessments completed by sixth-grade children and their caregivers. The sample comprised 245 mother–child pairs of children born between April 2, 2009, and April 1, 2012.
Results
Postpartum depressive symptoms were significantly associated with bonding difficulties. Structural equation modeling indicated that EPDS scores, MIBS-J scores, and child sex were significant predictors of psychosocial difficulties in sixth grade. Bonding difficulties mediated 34.6% of the total effect of postpartum depression on child difficulties. The models accounted for 26.1% of variance in overall psychosocial difficulties, with 43.0% explained for parent-rated SDQ scores and 36.4% for self-rated SDQ scores.
Conclusions
The study suggests that maternal depressive symptoms can undermine mother-to-infant bonding, contributing to increased emotional and behavioral challenges in children later in childhood. These findings highlight the importance of early postpartum interventions that address both maternal mental health and bonding to reduce long-term negative effects on child development.