Background: Dialectical behaviour therapy (DBT) and mentalisation-based therapy (MBT) are both widely used evidence-based treatments for borderline personality disorder (BPD), yet a head-to-head comparison of outcomes has never been conducted. The present study therefore aimed to compare the clinical outcomes of DBT v. MBT in patients with BPD.
Methods: A non-randomised comparison of clinical outcomes in N = 90 patients with BPD receiving either DBT or MBT over a 12-month period.
Results: After adjusting for potentially confounding differences between participants, participants receiving DBT reported a significantly steeper decline over time in incidents of self-harm (adjusted IRR = 0.93, 95% CI 0.87-0.99, p = 0.02) and in emotional dysregulation (adjusted β = -1.94, 95% CI -3.37 to -0.51, p < 0.01) than participants receiving MBT. Differences in treatment dropout and use of crisis services were no longer significant after adjusting for confounding, and there were no significant differences in BPD symptoms or interpersonal problems.
Conclusions: Within this sample of people using specialist personality disorder treatment services, reductions in self-harm and improvements in emotional regulation at 12 months were greater amongst those receiving DBT than amongst those receiving MBT. Experimental studies assessing outcomes beyond 12 months are needed to examine whether these findings represent differences in the clinical effectiveness of these therapies.
Keywords: Behaviour therapy; borderline personality disorder; psychodynamic therapy; psychological treatment.