The Cumulative Effects of Bullying Victimization in Childhood and Adolescence on Borderline Personality Disorder Symptoms in Emerging Adulthood

We examined how bullying victimization across childhood and adolescence was associated with BPD symptoms in emerging adulthood. Participants were drawn from the McMaster Teen Study, representing a community sample. A three-class solution of bullying victimization trajectories was selected from a semi-parametric group-based trajectory analysis (ages 10 to 18, n = 701). Most individuals followed a low decreasing trajectory (71.3%), followed by a moderate stable trajectory (25.2%) and a high stable trajectory (3.5%), which predicted BPD symptoms in emerging adulthood (ages 19 to 22; n = 338). Results indicated that the high stable and moderate stable groups differed from the low decreasing group on BPD symptoms; individuals who were bullied by peers in childhood and adolescence were more likely to have elevated symptoms of BPD in adulthood. When controlling for gender and childhood maltreatment, this differentiation only held true for the high stable group. Results suggest that peer relations are powerful enough to influence subsequent personality pathology. Implications are examined through a developmental trauma framework. © 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG.