Objective: This study presents data from a randomized outcome study comparing mentalization-based and supportive psychotherapy for patients with borderline personality disorder (BPD).
Method: Eighty-five SCID-II diagnosed borderline patients were randomized to either i) 2 years of intensive (twice weekly) combined (individual and group), mentalization-based psychotherapy (MBT) or ii) 2 years of less-intensive (biweekly) supportive group therapy. Treatment outcome was assessed using a battery of self-report questionnaires, SCID-II interviews and therapist-rated global assessment of functioning (GAF).
Results: Fifty-eight patients completed 2 years of treatment. Significant changes in both treatment groups were identified for several outcome measures, including self-reported measures of general functioning, depression, social functioning and number of diagnostic criteria met for BPD, as outlined by the SCID-II interview. General linear modelling was used to compare treatment outcome in the two groups. Only GAF showed a significantly higher outcome in the MBT group. A trend was found for a higher rate of recovery from BPD in the MBT group. Pre-post effect sizes were high (0.5–2.1) and for the most part highly significant in both groups.
Conclusion: The study indicates that both MBT and supportive treatment are highly effective in treating BPD when conducted by a well-trained and experienced psychodynamic staff in a well-organized clinic.