Low Caregiver-Child Positive Escalation in Childhood Predicts Late Adolescent BPD.

Borderline personality disorder (BPD) and major depressive disorder (MDD) are highly comorbid, yet little is known about developmental family processes that distinguish between individuals who will go on to develop MDD versus BPD. Using longitudinal, observational data from the Preschool Depression Study, we tested whether caregiver behaviors and caregiver-child interaction patterns during a conflict discussion task predicted later BPD vs. MDD symptoms. Caregiver-child dyads (N = 161) completed five-minute conflict discussions at up to three timepoints across late childhood and early adolescence; these discussions were observationally coded for caregiver and dyadic behaviors. Outcomes were self-reported BPD symptoms and clinical interview-based MDD symptoms assessed in late adolescence. After controlling for caregiver BPD and MDD and correcting for the false discovery rate, hierarchical linear regression models showed that lower dyadic positive escalation between caregiver and child predicted elevated BPD symptoms in late adolescence. Associations with MDD symptoms were not significant. These findings suggest that maintaining or building positive affect during challenging caregiver-child interactions may be a protective interpersonal process that is more specific to risk for BPD than risk for MDD. Implications for our understanding of the development of BPD versus MDD in childhood and adolescence are discussed.