Short Video-Based Mental Health Intervention for Depressive Symptoms in Junior High School Students: A Cluster Randomized Controlled Trial

Purpose: Digital interventions for adolescent mental health are emerging in high-income countries, but have faced challenges and are scarce in China. This study investigated the effect of a short video-based mental health intervention on depressive symptoms in Chinese adolescents. Methods: A three-arm cluster randomized controlled trial was conducted in four junior high schools in Shanghai from December 2020 to December 2021 with the measurement at baseline, 6 months after study entry, and 12 months. Outcomes were collected by self-completed questionnaires administered by teachers masked to allocation. The primary outcome was depressive symptoms assessed by the Depression Self-Rating Scale for Children (DSRSC). Mixed effects models were used to compare psychologist-led intervention (n=428 students) and teacher-led intervention (n=385) including six short video-based sessions to usual school provision (n=751). Results: Using intention-to-treat analyses, psychologist-led intervention showed more reduction in depressive symptoms compared to usual school provision at 6 months (coefficient -1.00, 95% CI -1.94 to -0.05), but not at 12 months. Using per-protocol analyses among participants who watched at least three video episodes, both psychologist-led (-1.14, -2.20 to -0.09) and teacher-led intervention (-1.23, -2.45 to -0.02) reduced depressive symptoms compared to usual school provision at 6 months, and the effect of teacher-led intervention persisted at 12 months (-1.58, -3.13 to -0.03). Further exploration found that compared with urban students, the between-group differences for depressive symptoms in rural students were more significant (p<0.05 for interaction) and the effects were maintained at 12 months. Conclusion: The short video-based mental health intervention showed potential to reduce depressive symptoms among Chinese adolescents, and the effects were more significant if the minimum video viewing frequency was reached.