Effectiveness of a brief psychotherapeutic intervention compared with treatment as usual for adolescent nonsuicidal self-injury: a single-centre, randomised controlled trial.

Although nonsuicidal self-injury (NSSI) is a clinically significant behavior, evidence-based, specific, time-, and cost-effective treatment approaches are lacking. The aim of this study was to compare the efficacies of a brief cognitive-behavioral psychotherapy manual, the Cutting Down Programme (CDP), and treatment as usual (TAU) in the treatment of adolescent NSSI. We conducted a single-centre randomised controlled trial (RCT). Eligible participants were aged 12-17 years engaging in repetitive NSSI (at least 5 times within the past 6 months). We randomly allocated 74 participants to CDP (n = 37) or TAU (n = 37; in a 1:1 ratio). Outcome measures were administered before treatment (T0), directly after CDP or 4 months after baseline evaluation in the TAU group (T1), and another 6 months later (T2; primary endpoint). Primary outcome was a 50% reduction in NSSI frequency within the past 6 months at 10-month follow-up (T2). Regarding the primary outcome, there were no significant differences between the CDP (n = 26; 70.3%) and TAU group [n = 27; 73.0%; χ(1) = 0.07; p = 0.797]; NSSI frequency within the past 6 months was significantly reduced at T2 [χ(1) = 12.45; p < 0.001] with no between-group difference [χ(1) = 0.14; p = 0.704]. However, we found a significant group x point of measurement interaction [χ(2) = 7.78; p = 0.021] regarding NSSI within the last month indicating at T1. CDP was equally effective and achieved faster recovery compared to a significantly more intensive TAU in treating adolescent NSSI. The CDP could provide a brief and pragmatic first treatment within a stepped-care model for NSSI in routine clinical care.Clinical Trial Registration The trial was prospectively registered in the German Registry of Clinical Trials (https://www.drks.de; DRKS00003605) and is now complete.