What Emerging Treatments Teach us About Psychotherapy for Adolescent Personality Disorder and the Road Ahead

This commentary, written for Journal of Clinical Psychology: In Session, synthesizes five case-based contributions on psychotherapy for adolescents with personality disorders (PDs). Although PDs often emerge in adolescence, age-adapted treatments remain scarce. Randomized clinical trials are still limited, making carefully constructed case studies important for identifying promising treatments. Three of the featured cases draw on mentalization-based therapy for adolescents, implemented in combined group-individual formats, adapted toward dimensional models of PD, or extended socioecologically to involve wider social networks, such as family, peers, and school systems. The remaining two derive from metacognitive approaches: one applying Metacognitive Interpersonal Group Therapy (MIT) for Adolescents in a case of dependent and borderline PD, and the other applying MIT for Eating Disorders with an adolescent with binge eating disorder and comorbid avoidant and obsessive-compulsive PD. Across studies, four shared priorities emerge. First, the capacity to think, reason, and regulate mental states, defined as mentalizing or metacognition, serves as a central mechanism of change. Second, impairments in self and interpersonal functioning are treated as the core pathology in PDs. Third, therapeutic progress depends on actively engaging the adolescent's broader social context rather than working solely within the therapist-patient dyad. Fourth, comorbidity, whether trauma-related disorders, substance use, eating disorders, or others, should be treated integratively to ensure targeted, personalized treatment. These cases demonstrate that innovation in adolescent PD treatment often begins with single cases. The task ahead is to translate these clinical examples into rigorously tested, developmentally sensitive, and ecologically grounded intervention models that can be applied in early intervention programs.