Despite an expanding body of research pertaining to Borderline Personality Disorder (BPD) in child and adolescent populations, controversy remains regarding the validity of youth BPD.

To determine the aetiological and psychopathological validity of youth BPD.

Electronic databases were searched for studies examining the aetiological (i.e., the extent to which youth and adult BPD share common risk factors) and psychopathological (i.e., the extent to which youth and adult BPD share common symptoms and associated behaviours) validity of BPD in populations under 18 years of age. Forty-three studies were identified satisfying the predetermined inclusion criteria for meta-analysis.

Statistically significant pooled associations with youth BPD were observed for sexual (OR=4.90; 95% CI=3.12, 7.70) and physical (OR=2.82; 95% CI=1.95, 4.07) abuse; maternal hostility/verbal abuse (OR= 3.28; 95% CI= 2.39, 4.51); and neglect (OR=3.45; 95% CI= 2.26, 5.28). Several psychopathological features were also associated with youth BPD, including comorbid mood (OR= 3.29; 95% CI= 2.36, 4.59), anxiety (OR= 2.13; 95% CI=1.45, 3.14) and substance use (OR=4.59; 95% CI=2.84, 7.43) disorders; self-harm (OR: 5.53; 95% CI=2.59, 11.81) and suicide ideation (OR=3.71; 95% CI =2.22, 6.21).

Findings indicate that adult and youth BPD share common aetiological and psychopathological correlates. This indicates some diagnostic validity of youth BPD and supports clinical recognition in this age group.