Dialectical Behaviour Therapy for Eating Disorders With Comorbid Borderline Personality Disorder: A Systematic Review...

Borderline personality disorder (BPD) and eating disorders (EDs) frequently co-occur and are associated with heightened clinical severity and emotion dysregulation. This systematic review aimed to synthesize empirical evidence on the effectiveness of dialectical behaviour therapy (DBT) in improving eating disorder outcomes among individuals with comorbid BPD and EDs.

A systematic literature search was conducted across Wiley, Web of Science, SpringerLink and Scopus databases in accordance with PRISMA 2020 guidelines. Studies were included if they examined DBT-based interventions in samples with comorbid BPD and EDs and reported quantitative outcomes. Eight studies met inclusion criteria. Risk of bias was assessed using Joanna Briggs Institute (JBI) checklists, and a structured narrative synthesis was performed.

Across studies, DBT-based interventions were associated with reductions in eating disorder symptom severity, maladaptive eating behaviours (e.g., binge eating and purging) and self-harm. Baseline BPD symptom severity did not consistently predict poorer outcomes and, in some cases, was associated with greater early improvements. However, substantial heterogeneity in study design, sample characteristics and outcome measures was observed, and methodological quality varied across studies.

DBT appears to be a clinically relevant and promising transdiagnostic intervention for individuals with comorbid BPD and EDs. Nevertheless, the current evidence base is limited by methodological constraints, highlighting the need for well-designed randomized controlled trials and mechanism-focused research. These findings have important implications for clinical practice, supporting the use of DBT as a transdiagnostic intervention in complex comorbid populations.