Presentation Information

[O-8-03]Effectiveness of a Multimedia-Based Acceptance and Commitment Therapy (ACT) Intervention for Adolescent Mental Health in China: A Cluster Randomized Controlled Trial with Mediation Analysis

*Yuting Yang1, Jingyi Wang1, Xiaomin He1, Haijiang Lin2, Fei Yan1, Wei Wang1, Qi Zhao1, Xinping Zhao1, Chaowei Fu1 (1.Fudan University(China), 2.Taizhou City Center for Disease Control and Prevention(China))
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Keywords:

Multimedia-based intervention,Adolescents,Mental health,Loneliness,Randomized controlled trial

Purpose: Adolescent mental health challenges are increasingly prevalent, yet access to effective psychological support remains limited, particularly in China. Multimedia-based interventions may provide a scalable and accessible solution. This study aimed to evaluate the effectiveness of a multimedia-based Acceptance and Commitment Therapy (ACT) intervention on adolescent mental health and examine whether changes in loneliness mediated intervention effects.
Methods: A two-arm cluster randomized controlled trial was conducted in eight middle schools in Taizhou City, China. Schools were randomly assigned (1:1) to receive either a teacher-led, multimedia-based ACT intervention (short videos, audio tracks, group discussions, and leaflets) or a self-guided ACT intervention delivered through leaflets (the control group). Within each school, three classes from grades 7-8 or 10-11 were randomly selected. Online assessments were conducted at baseline, 3 months (end of intervention), and 12 months. Primary outcomes included stress, depression, anxiety, and emotional and behavioral problems. Mixed-effects models under the intention-to-treat principle were used, with a prespecified mediation analysis examining loneliness as a mediator.
Results: From October 2023 to November 2024, 2,103 eligible participants were enrolled (1,055 intervention; 1,048 control). Follow-up data were available for 1,945 (92.5%). At 3-month follow-up, the intervention group showed significantly greater reductions in stress (adjusted mean difference -1.20, 95% CI -1.73 to -0.67; p < 0.001), depression (-1.23, -1.85 to -0.61; p < 0.001), anxiety (-0.86, -1.24 to -0.49; p < 0.001), and emotional and behavioral problems (-1.16, -1.65 to -0.66; p < 0.001) compared to the control group. The reductions were maintained to 12-month follow-up. Mediation analysis indicated that reductions in loneliness partially mediated the intervention effects on all primary outcomes.
Conclusion: The multimedia-based ACT intervention effectively improved adolescent mental health with sustained benefits. Scalable digital approaches hold promise for school-based mental health promotion. Targeting loneliness may be a key mechanism to enhance intervention effectiveness.