Brief Psychotherapeutic Intervention Compared with Treatment as Usual for Adolescents with Nonsuicidal Self-Injury: Outcomes over a 2–4-Year Follow-Up

The "Cutting Down Programme" (CDP), a brief psychotherapeutic intervention for treating nonsuicidal self-injury (NSSI) in adolescents, was comparable to high-quality treatment as usual (TAU) in a previous randomized controlled trial (RCT).The aim of the study was to evaluate the long-term outcomes of the CDP over up to 4 years.Assessments of NSSI, suicide attempts, borderline personality disorder (BPD), depression, and quality of life took place 2 to 4 years (T3) after enrollment in a RCT. The evolution of NSSI, suicide attempts, depression, and quality of life was analyzed using (generalized) linear mixed-effects models. Ordered logistic regression was used for analyzing BPD diagnoses. Data from T0, T2, and T3 are reported.Out of 74 patients, 70 (95%) were included in the T3 assessment. The frequency of NSSI events alongside with suicide attempts and depression further decreased between T2 and T3 and BPD between T0 and T3 in both groups. Quality of life remained stable in both groups between T2 and T3. Both groups received substantial but comparable additional treatment between T2 and T3. More treatment sessions during the follow-up period were linked to larger improvements of NSSI.The CDP was found to be as effective as TAU in promoting recovery from NSSI and comorbid symptoms in the long term. Results suggest that treatment effects from a brief psychotherapeutic intervention may endure and even further improve after completion of the program. However, additional treatment seems to improve chances for recovery independent from CDP versus TAU.