Exploring borderline personality features in adolescents: which features best predict borderline personality disorder

Borderline personality disorder (BPD) is a severe mental disorder that can manifest and be treated during adolescence. Borderline Feature Scale for Children (BPFS-C) was developed with the intention to assess children and adolescents with suspected personality pathology. This study aimed to determine which of the four BPD domains of BPFS-C (affective instability, identity problems, negative relationships, and self-harm) most notably explain the variance of the BPD construct, in a clinical sample with diagnosed BPD and non-clinical group. Our hypothesis is that affective instability plays a central role in elucidating this variance. The study involved 642 Danish participants aged 14–18, including a clinical group of 111 with BPD and 531 healthy controls. BPFS-C was used to identify borderline personality features within the two groups. We conducted an independent samples t-test to assess the influence of group membership on the domains. Discriminant analysis was conducted to explore the impact of four domains on the probability of exhibiting BPD. Our findings reveal that affective instability was the domain with most explanatory value to distinguish between adolescents with and without BPD. Due to the heterogeneity of BPD, identification of early risk markers are crucial for early detection and interventions and potentially preventive for the development of severe borderline personality disorder in adolescents.