Effects of a School-Based Trauma-Informed Psychosocial Competence Intervention on Nonsuicidal Self-Injury in Adolescents

The purpose of this randomized controlled trial is to evaluate whether a school-based Trauma-Informed Psychosocial Competence (TIPC) intervention can reduce nonsuicidal self-injury among adolescents in China. Nonsuicidal self-injury means deliberately injuring oneself without intending to die. The TIPC program aims to help adolescents understand and accept themselves, manage difficult emotions, cope with stress, communicate with others, and seek support. It uses a trauma-informed approach that recognizes how stressful or adverse experiences may affect young people and emphasizes safety, respect, and supportive relationships. The main question is whether adolescents receiving the TIPC program show a greater reduction in nonsuicidal self-injury than those in the comparison group. The study will also examine changes in emotional well-being and psychosocial functioning. Participants will be assigned to an intervention group or a comparison group through random allocation. Adolescents in the intervention group will take part in structured school-based sessions. Participants in both groups will complete questionnaires before and after the intervention to assess self-injury and related psychological and social outcomes.

Inclusion Criteria: * Enrolled as a student in a participating school and within the grade levels selected for recruitment. * Able to understand the Chinese-language study materials and participate in the intervention activities and questionnaire assessments, with reasonable support where needed. * Willing to participate and provide informed assent or consent, as appropriate for age. * Written informed consent provided by a parent or legal guardian for participants below the applicable age of legal consent. Exclusion Criteria: * A condition that prevents informed assent or consent, participation in the intervention, or completion of the study assessments despite reasonable support. * Concurrent participation in another structured intervention trial targeting nonsuicidal self-injury that would conflict with participation in this study.