RESUMO
Non-suicidal self-injury (NSSI) is the deliberate and self-inflicted damage to body tissue in the absence of fatal intent, and has become a serious health problem among adolescents. The aim of this study was to evaluate the efficacy of treatment for NSSI in this population through a systematic revision and meta-analysis (PROSPERO ID: 252355). Studies with therapies that reduced NSSI were included. The search was performed in the Medline, APA PsycINFO and PubPsych databases. The synthesis of measures for the main outcome (NSSI reduction) and for secondary outcomes (global functioning change and depressive symptomatology reduction) was performed using a random effects model. The search identified a total of 1881 studies. The systematic review included five studies and the meta-analysis four studies. The summary effect estimate for the standardized mean difference in NSSI was -0.53 (95% CI: -0.82, -0.25), in global functioning it was 0.62 (95% CI: 0.34, 0.91), and in depressive symptomatology it was -0.59 (95% CI: -0.82, -0.36). The certainty of the evidence using the GRADE method is low. We conclude that therapies specifically aimed at reducing NSSI are effective in reducing both NSSI and depressive symptoms while increasing global functioning.