Bullied by peers in childhood and borderline personality symptoms at 11 years of age: a prospective study.

BACKGROUND: Abuse by adults has been reported as a potent predictor of borderline personality disorder (BPD). Unclear is whether victimisation by peers increases the risk of borderline personality symptoms.

METHOD: The Avon Longitudinal Study of Parents and Children (ALSPAC) prospective, longitudinal observation study of 6050 mothers and their children. Child bullying was measured by self-report and mother and teacher report between 4 and 10 years. Family adversity was assessed from pregnancy to 4 years; parenting behaviours from 2 to 7 years, sexual abuse from 1.5 to 9 years, and IQ and DSM-IV axis I diagnoses at 7 to 8 years. Trained psychologists interviewed children at 11.8 years to ascertain DSM-IV BPD symptoms (five or more).

RESULTS: Accounting for known confounders, victims of peer bullying had an increased risk of BPD symptoms according to self-report (OR, 2.82; 95% CI, 2.13-3.72); mother report (OR, 2.43; 95% CI, 1.86-3.16); and teacher report (OR, 1.95; 95% CI, 1.34-2.83). Children who reported being chronically bullied (OR, 5.44; 95% CI, 3.86-7.66) or experienced combined relational and overt victimisation (OR, 7.10; 95% CI, 4.79-10.51) had highly increased odds of developing BPD symptoms. Children exposed to chronic victimisation according to mother report were also at heightened risk of developing BPD symptoms (OR, 3.24; 95% CI, 2.24-4.68).

CONCLUSIONS: Intentional harm inflicted by peers is a precursor or marker on the trajectory towards the development of BPD symptoms in childhood. Clinicians should be adequately trained to deal with, and ask users of mental health services routinely about, adverse experiences with peers.