Ten-session school-based mental health package reduces depressive and anxiety symptoms in Chinese adolescents compared to routine curriculum.

This cluster-randomised controlled trial investigated the efficacy of a school-based mental health intervention among Chinese adolescents. The study was conducted across public schools in ten provinces in China, involving a total sample of 5,222 participants. The population consisted of adolescents with a mean age of 13.6 years, comprising 51.5% girls and 48.5% boys. The study design utilized a cluster-randomisation approach, assigning entire schools to either the intervention or control arm rather than randomising individual students. The intervention phase was not reported, and the specific publication type was not reported in the available data.

The intervention consisted of ten weekly sessions, each lasting 40 minutes, delivered by trained school-based mental health teachers or counsellors. These sessions utilized the Adolescent Mental Health Service Package (AMHSP), which was delivered using standardised manuals and multimedia materials. The comparator group received the routine school curriculum without any additional mental health content. This design aimed to test the feasibility and impact of integrating mental health promotion directly into the existing school schedule without requiring external specialists.

The primary outcomes assessed included depressive symptoms, anxiety symptoms, subjective wellbeing, and emotion regulation. At the one-month follow-up, the intervention group demonstrated significantly lower depressive symptoms relative to the control group. The effect size was a Standardised Mean Difference (SMD) of -0.09, with a 95% confidence interval ranging from -0.14 to -0.04 and a p-value of 0.0013. Similarly, anxiety symptoms were significantly lower in the intervention group compared to controls, with an SMD of -0.11, a 95% CI of -0.16 to -0.05, and a p-value of 0.0002.

Regarding secondary outcomes, no statistically significant differences were observed between groups for subjective wellbeing. The effect size for subjective wellbeing was an SMD of 0.02, with a 95% CI of -0.03 to 0.08 and a p-value of 0.85. Furthermore, the intervention did not result in significant differences in emotion regulation measures. Specifically, cognitive reappraisal showed an SMD of 0.03 (95% CI -0.02 to 0.09, p=0.33), and expressive suppression showed an SMD of -0.08 (95% CI -0.14 to -0.01, p=0.10). No absolute numbers were reported for these outcomes.

Safety and tolerability findings indicated that no adverse events were reported during the study period. Data on serious adverse events, discontinuations, and specific tolerability metrics were not reported. The study was funded by UNICEF. The authors noted a key methodological limitation: neither the students nor the facilitators were masked to the group allocation. This lack of blinding may introduce bias, although the cluster-randomised design and the nature of the intervention mitigate some concerns. The certainty of the evidence was not formally reported.

These results support the potential of a low-intensity, curriculum-integrated approach to promoting adolescent mental health. The study demonstrates a scalable strategy for early mental health promotion within the school setting, which is particularly relevant given the high prevalence of mental health issues in adolescents. However, the lack of masking and the absence of long-term follow-up data beyond one month limit the ability to draw definitive conclusions regarding sustained efficacy. Questions remain regarding the long-term maintenance of symptom reduction and the generalisability of these findings to other cultural or educational contexts. Clinicians should consider these findings as evidence supporting school-based mental health initiatives, while acknowledging the inherent limitations of the trial design.