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

The AMHSP intervention significantly reduced depressive symptoms compared to control at 3-month follow-up.

• Standardised mean difference (SMD) of -0.09 (95% CI -0.14 to -0.04) at 3 months
• pFDR=0.0013 after Benjamini-Hochberg false discovery rate correction
• Depressive symptoms measured using the nine-item Patient Health Questionnaire (PHQ-9)
• Analysis conducted in the intention-to-treat population of 5222 students using linear mixed-effects models

The AMHSP intervention significantly reduced anxiety symptoms compared to control at 3-month follow-up.

• SMD of -0.11 (95% CI -0.16 to -0.05) at 3 months
• pFDR=0.0002 after Benjamini-Hochberg false discovery rate correction
• Anxiety symptoms measured using the seven-item Generalized Anxiety Disorder Scale (GAD-7)
• This was the strongest significant effect among the four coprimary outcomes

The AMHSP intervention did not significantly improve subjective wellbeing at 3-month follow-up.

• SMD of 0.02 (95% CI -0.03 to 0.08) at 3 months
• pFDR=0.85, indicating no significant difference from control
• Subjective wellbeing measured using the WHO Five-item Well-Being Index (WHO-5)

The AMHSP intervention did not significantly improve emotion regulation (cognitive reappraisal or expressive suppression) at 3-month follow-up.

• Cognitive reappraisal SMD 0.03 (95% CI -0.02 to 0.09), pFDR=0.33
• Expressive suppression SMD -0.08 (95% CI -0.14 to -0.01), pFDR=0.10
• Emotion regulation measured using the ten-item Emotion Regulation Questionnaire (ERQ)
• Neither subscale reached statistical significance after FDR correction

The trial enrolled 5222 students from 18 public schools across ten provinces in China.

• 120 classrooms were randomised 1:1 to intervention (n=2620) or control (n=2602)
• Mean age of participants was 13.6 years (SD 1.7); 2687 (51.5%) girls and 2535 (48.5%) boys
• Trial conducted between Oct 12, 2023 and Oct 10, 2024
• All participants who completed at least one assessment were included in the primary outcome (intention-to-treat) analysis
• Classrooms within each school were the unit of randomisation

The AMHSP intervention consisted of ten weekly 40-minute sessions delivered by trained school-based mental health teachers or counsellors.

• Facilitators used standardised manuals and multimedia materials
• The programme is described as a 'multicomponent, culturally adapted, evidence-informed curriculum grounded in Positive Youth Development'
• The intervention was designed to reduce depressive and anxiety symptoms and enhance mental wellbeing
• Delivery by school-based staff was intended to demonstrate a scalable strategy for early mental health promotion

No adverse events were reported in either group during the trial.

• This finding applied across the full sample of 5222 participants
• Outcomes were assessed at baseline, immediately after intervention, and at 1-month and 3-month follow-up
• Neither students nor facilitators were masked to group allocation given the nature of the school-based intervention
• All statistical analyses were performed by an independent statistician masked to group allocation