Efficacy of mentalization-based therapy in treating self-harm: A systematic review and meta-analysis.

Introduction: Mentalization-based therapy (MBT) and its adapted version for adolescents (MBT-A) are repeatedly highlighted as promising treatments for reducing self-harm, particularly in borderline personality disorder (BPD). Despite the availability of publications providing evidence of their efficacy in reducing self-harm, recent meta-analyses have yielded mixed results. To inform best-practice clinical decision-making, we conducted a systematic review and meta-analysis. We aimed to disentangle findings for both adolescents and adults on the efficacy of MBT(-A) in reducing self-harm (primary outcome) and symptoms of BPD and depression (secondary outcomes).

Methods: Web of Science, Scopus, Embase, PubMed/Medline, and Cochrane Review Database were searched for eligible studies published until September 2022. In total, 14 studies were identified, comprising 612 participants from nine MBT studies (six pre-post, three RCTs) and five MBT-A studies (two pre-post, three RCTs). Aggregated effect sizes were estimated using random-effects models. Meta-regressions were conducted to assess the effect of moderator variables (treatment duration, drop-out rates, and age) on effect sizes.

Results: Overall, both MBT and MBT-A demonstrated promising effects in reducing self-harm (g = -0.82, 95% CI -1.15 to -0.50), borderline personality disorder (g = -1.08, 95% CI -1.38 to -0.77), and depression (g = -1.1, 95% CI -1.52 to -0.68) symptoms. However, when compared to control interventions (TAU, SCM), MBT(-A) did not prove to be more efficacious, with the exception of MBT showing superior effects on BPD symptoms in adults (g = -0.56, 95% CI -0.88 to -0.24).

Conclusion: Although the pre-post evaluations seem promising, this analysis, including RCTs, showed no superiority of MBT(-A) to control conditions, so that prioritizing the application of MBT (-A) for the treatment of self-harm is not supported. Possible explanations and further implications are discussed.