A quasi‐cluster randomized controlled trial of a classroom‐based mental health literacy educational intervention to promote knowledge and help‐seeking/helping behavior in adolescents

School-based education is a potentially effective approach for improving mental health literacy (MHL) in adolescents. This study evaluated the effects of the "Short MHL Program (SMHLP)", a brief (50 min), school teacher-led program, on MHL in adolescents in a quasi-cluster randomized controlled trial.A total of 975 high school first graders (age 15-16) in Japan were allocated to classes such that gender and academic achievement ratios were almost equivalent at the time of admission to the high school. They were assigned at the class level to the SMHLP (n = 364 from 10 classes) or a control group (n = 611 from 17 classes). The program consisted of a 50-minute session and was delivered by a school teacher. The students completed a self-report questionnaire at 3 time points: pre-, (immediately) post- and 2-month follow-up. Outcomes included "Knowledge about mental health/illnesses", "Recognition of the necessity to seek help", "Intention to seek help", and "Intention of helping peers". Mixed effects modeling was employed for analyses.Scores of all outcomes were significantly improved in the intervention group compared to the control group post-intervention (p.001). These improvements were maintained at 2-months follow-up for all outcomes (p.001-.05). Questionnaire scores did not differ between groups at baseline.The effect of the SMHLP was confirmed in grade 10 students. Brief, yet effective programs can be a viable option to promote understanding of mental health problems and have the potential to be incorporated into regular school curriculum. ".