The effects of mother-infant bonding on children's strengths and difficulties.

Background: Several studies have shown that parental relationships between infants and their caregivers, and their mental health condition in childhood, influence children's development. The present study aimed to predict the effects of maternal mental health and mother-infant bonding at 10 months of age on Japanese children's behavioral development at 5 years. We analyzed factors including maternal mental health and mother-infant bonding to predict subtype classes as a prospective cohort study. Methods: Data from Japan's Chiba Study of Mother and Child Health (C-MACH) were used. The Japanese versions of the Mother-to-Infant Bonding Scale (MIBS) and Strengths and Difficulties Questionnaire (SDQ) were administered to 275 consenting mothers and their children. We used latent class analysis (LCA) to classify the children's characteristics. We analyzed the relationship between sociodemographics, maternal mental states, and latent classes using ANOVA and multinomial logistic regression. Results: Three latent classes were found: "asocial" (41.3 %), "well-adjusted" (20.3 %), and "highly difficult" (38.4 %). Children in the "asocial" class had a low probability for all behaviors (emotional, conduct, hyperactivity, peer problems, and prosocial behaviors). Children in the "highly difficult" class were more likely to exhibit conduct problems, hyperactivity, and peer problems as well as fewer prosocial behaviors. In addition, there were more males in the "asocial" class than in the "well-adjusted" class (Odds Ratio (OR) = 0.30, 95 % confidence interval (CI) [0.11; 0.83]), and they had higher MIBS 10-month scores (OR = 1.39, 95%CI [1.00; 1.94]).There were fewer females in the "highly difficult" than in the "well-adjusted" class (OR = 0.16, 95 % CI [0.06; 0.43]), and they had higher MIBS 10-month scores (OR = 1.65, 95%CI [1.21; 2.26]). Conclusions: The results suggest that insufficient mother-infant bonding at 10 months may contribute to males' asocial behavior at five years. These findings can help parents better understand and manage these issues in their children for prevention and intervention.