Pilot Cluster RCT of an Indirect Contact Mental Health Literacy Program for 5th-Grade Students

This cluster-randomized pilot trial will evaluate the preliminary effects and feasibility of adding an indirect contact component to a school-based mental health literacy (MHL) lesson for 5th-grade students in a public elementary school in Tokyo, Japan. Four 5th-grade classes (approximately 150 students in total) will be randomized by class (two classes per arm). All students will receive a 45-minute lesson that includes an animated video and educational slides. In the intervention arm, teachers will additionally introduce a short story about a well-known soccer player who experienced and recovered from a mental health condition, serving as an indirect contact element. The control arm will receive the standard lesson without this component. Students will complete questionnaires at baseline (T1), immediately after the lesson (T2), and 2-3 months later (T3). The primary outcome is vignette-based social distance toward a peer with mental health problems. Secondary outcomes include mental health knowledge, help-seeking intentions, perceived need for help, intended sources of help. As a pilot study with only four clusters, the trial is not powered to detect small effects; findings will be used to estimate effect sizes and assess feasibility for a future larger-scale trial.