Universal school-based transdiagnostic interventions to improve mental health and wellbeing among Chinese adolescents: a two-group, cluster-randomised controlled trial.

Abstract

Mental health problems, including depression, anxiety, and suicide, pose a substantial burden on adolescents worldwide, making prevention a priority. In China, major challenges remain in implementing and evaluating school-based mental health programmes. The Adolescent Mental Health Service Package (AMHSP) is a multicomponent, culturally adapted, evidence-informed curriculum that is grounded in Positive Youth Development and designed to reduce depressive and anxiety symptoms and enhance mental wellbeing. The aim of this study was to evaluate the AMHSP for improving adolescent mental health in routine school settings. This cluster-randomised controlled trial included public schools across ten provinces in China, with participants nested within schools and classrooms within each school randomly assigned 1:1 to either ten weekly 40-min AMHSP sessions (intervention), delivered by trained school-based mental health teachers or counsellors (facilitators) using standardised manuals and multimedia materials, or routine curriculum without additional mental health content (control). Given the nature of the school-based intervention, neither students nor facilitators were masked to group allocation, but all statistical analyses were done by an independent statistician masked to group allocation, and student self-report data were collected anonymously using secure, standardised platforms. The four primary outcomes were depressive symptoms (measured by nine-item Patient Health Questionnaire), anxiety symptoms (seven-item Generalized Anxiety Disorder Scale), subjective wellbeing (WHO Five-item Well-Being Index), and emotion regulation (ten-item Emotion Regulation Questionnaire, assessing both cognitive reappraisal and expressive suppression), which were self-reported at baseline, immediately after intervention, and at 1-month and 3-month follow-up. The primary outcome analysis of change from baseline at 3 months' follow-up in the four coprimary outcomes was analysed by linear mixed-effects models in the intention-to-treat population, which included all participants who completed at least one assessment. To control for multiple testing, we prespecified the use of the Benjamini-Hochberg false discovery rate (FDR) correction of p values. This trial was prospectively registered with the Chinese Clinical Trial Registry (ChiCTR2300076956) and has been completed. Between Oct 12, 2023 and Oct 10, 2024, 5222 students from 120 classrooms in 18 public schools (mean age 13·6 years [SD 1·7]; 2687 [51·5%] girls and 2535 [48·5%] boys) were randomly assigned to the AMHSP intervention (n=2620) or control (n=2602), completed the baseline assessments, and were included in the primary outcome analysis. At 3 months, the AMHSP intervention group showed lower depressive symptoms (standardised mean difference [SMD] -0·09 [95% CI -0·14 to -0·04], p_FDR=0·0013) and anxiety symptoms (-0·11 [-0·16 to -0·05], p_FDR=0·0002) relative to the control group. No differences were seen in subjective wellbeing (SMD 0·02 [-0·03 to 0·08], p_FDR=0·85) or emotion regulation (cognitive reappraisal SMD 0·03 [-0·02 to 0·09], p_FDR=0·33; expressive suppression -0·08 [-0·14 to -0·01], p_FDR=0·10) at 3 months. No adverse events were reported. The reduction in depression and anxiety symptoms 3 months after completing ten AMHSP sessions indicates a slow but meaningful benefit of the programme and supports the potential of a low-intensity, curriculum-integrated approach to promoting adolescent mental health. Delivery of the AMHSP by trained school-based mental health teachers demonstrates a scalable strategy for early mental health promotion in schools. UNICEF.