Abstract

Borderline personality disorder (BPD) is among the most severe mental health problems with long-lasting deterioration of functioning. According to a Cochrane review, evidence for methods focused on treatment for adolescent BPD patients is very limited. Aims of the study were to demonstrate the noninferiority of adolescent identity treatment (AIT) compared with dialectical behavior therapy for adolescents (DBT-A), and that intensive early treatment of BPD leads to significant improvement of psychosocial and personality functioning in adolescent patients. In a nonrandomized controlled trial using a noninferiority approach, we compared 37 patients treated with DBT-A with 23 patients treated with AIT. Both treatments included 25 weekly individual psychotherapy sessions and five to eight family sessions. Patients were assessed at four timepoints: baseline, posttreatment, 1- and 2-year follow-up. Primary outcome was psychosocial functioning at 1-year follow-up. We performed both intention-to-treat analyses and per-protocol analyses (completers). Baseline characteristics of both groups were not significantly different except for age and self-injurious behavior. In all, six AIT patients (26%) and 10 DBT-A patients (27%) dropped out of treatment. Both DBT-A and AIT significantly improved adolescents' psychosocial functioning (AIT: d = 1.82; DBT-A: d = 1.73) and personality functioning. BPD criteria and depression were significantly reduced by both treatments. Overall, AIT was found to be not inferior to DBT-A and even more efficient in reducing BPD criteria. Both treatments are highly effective in improving psychosocial functioning and personality functioning in adolescent BPD patients. AIT is a promising approach and not inferior to DBT-A in respect to treatment efficiency.