Patients with borderline personality disorder (BPD) have a 10% lifetime risk of death by suicide.1 Therefore, prevention of self-harm is an important target for treatment in this population. A recent Cochrane review2 concludes that dialectical behaviour therapy (DBT) is the most studied psychotherapeutic treatment for patients with BPD. The authors found that there were indications of beneficial effects for many psychotherapies, including DBT, for the BPD core symptoms and reduction of self-harm. One of the meta-analyses conducted regarding DBT compared with treatment as usual (TAU) showed a moderate statistically significant effect, indicating a beneficial effect in favour of DBT.2 Owing to the multicomponent nature of DBT treatment, Line…