Aim: Conduct a systematic review for the effectiveness of school mental health literacy programs to enhance knowledge, reduce stigmatizing attitudes and improve help-seeking behaviours among youth (12-25 years of age).

Methods: Reviewers independently searched PubMed, PsycINFO, Cochrane Library, CINAHL, ERIC, grey literature and reference lists of included studies. They reached a consensus on the included studies, and rated the risk of bias of each study. Studies that reported three outcomes: knowledge acquisition, stigmatizing attitudes and help-seeking behaviours; and were randomized controlled trials (RCTs), cluster RCTs, quasi-experimental studies, and controlled-before-and-after studies, were eligible.

Results: This review resulted in 27 articles including 5 RCTs, 13 quasi-experimental studies, and 9 controlled-before-and-after studies. Whereas most included studies claimed school-based mental health literacy programs improve knowledge, attitudes and help-seeking behaviour, 17 studies met criteria for high risk of bias, 10 studies for moderate risk of bias, and no studies for low risk of bias. Common limitations included the lack of randomization, control for confounding factors, validated measures and report on attrition in most studies. The overall quality of the evidence for knowledge and help-seeking behaviour outcomes was very low, and low for the attitude outcome.

Conclusions: Research into school-based mental health literacy is still in its infancy and there is insufficient evidence to claim for positive impact of school mental health literacy programs on knowledge improvement, attitudinal change or help-seeking behaviour. Future research should focus on methods to appropriately determine the evidence of effectiveness on school-based mental health literacy programs, considering the values of both RCTs and other research designs in this approach. Educators should consider the strengths and weaknesses of current mental health literacy programs to inform decisions regarding possible implementation.