Effectiveness of teacher-led mental health literacy programs on knowledge, stigma, and help-seeking in preteens: A cluster randomized controlled trial

Background: Teacher-delivered mental health literacy (MHL) education has been shown to be effective in adolescents. However, research is lacking regarding younger youths, including preteens, while the onset of mental illnesses starts to increase around this age. Methods: The effects of a concise (45-min) MHL program ( Short Mental Health Literacy Program ( SMHLP) for preteens ), delivered by teachers, are examined in grade-5 (aged 10-11) and 6 (aged 11-12) Japanese students from 8 public elementary schools. The students were randomly allocated by school to intervention (n = 532, 4 schools) and control (n = 869, 4 schools) groups. They completed a self-report questionnaire before, immediately after and three months after delivery of the program. The program was presented to the control group after completing the final questionnaire. The questionnaire covered knowledge about and attitudes to mental health/illnesses, including “intention to seek help”, “recognition of the necessity to seek help”, “intention to help peers” with mental problems, and “unwillingness to socialize with mentally ill people”. A mixed effects model was used for statistical analyses. Results:Knowledge and attitudes improved significantly more in the intervention group than the control group immediately after the intervention (p < .001), and the effect on knowledge was significant at the follow-up (p < .001) in grade-6 students. In grade-5 students, the effects were significant on knowledge and intention to seek help immediately after the intervention (p < .001) but were not maintained at follow-up. Conclusions: A concise teacher-delivered program may improve MHL in preteens aged 11-12, which might help improve/prevent mental health/illnesses. Trial registration: ClinicalTrials.gov NCT07116707. Registered on 6 August 2025. Retrospectively registered.