Borderline Personality Features Longitudinally Predict Personality Functioning Impairments Over 10 Months in Adolescents.

Borderline personality disorder (BPD) shows strong associations with the general factor of personality disorders, which is proposed to reflect the level of impairment in personality functioning as defined by Criterion A in the Alternative Model for Personality Disorders. Limited evidence regarding the convergent validity between BPD and Criterion A, particularly in developmental contexts, poses a barrier to integrating categorical and dimensional models of personality disorders. To address this, we employed a latent variable cross-lagged panel model to examine the longitudinal associations between BPD features and personality functioning in a two-wave adolescent cohort. Results revealed a unidirectional cross-lagged effect from BPD features to subsequent personality functioning impairments, suggesting that BPD may serve as a developmental marker of broader personality pathology. However, the absence of a reciprocal longitudinal effect raises questions about the sensitivity of personality functioning in capturing the developmental emergence of BPD symptomatology over time.