Maternal Bonding Impairment Predicts Personality Disorder Features in Adolescence: The Moderating Role of Child Temperament and Sex

Research has shown associations between adverse parenting experiences and (borderline) personality disorder ([B]PD). A biopsychosocial model suggests that child characteristics and the environment interact in the development of symptoms. However, prospective data in this aspect are limited. This study focused on maternal bonding impairment (MBI; 2 weeks postpartum) and its interactions with child temperament (age 5) and child sex as predictors of BPD symptoms and general personality dysfunction in adolescence. Participants were 64 mother-child dyads from a community sample who took part in a 14-year longitudinal study. Higher MBI was a significant predictor of general personality dysfunction as defined in Criterion A of the alternative model for PD of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Interactions showed that the effect of MBI on general personality dysfunction was decreased for children higher in harm avoidance and increased for children higher in novelty seeking. There was also a negative main effect of harm avoidance on (B)PD features. Regarding BPD symptoms, the MBI x Child Sex interaction indicated differential susceptibility. Girls' but not boys' BPD symptoms were dependent on maternal bonding. Our results indicate that children at risk of developing personality pathology can be identified early in life. They stress the importance of early relationship disturbances in the development of personality pathology and refine the understanding of differential susceptibility factors in the context of MBI and PD symptom development. Our findings can be applied to target at-risk dyads for selective early prevention based on temperament and maternal bonding.