Towards comprehensive mental health literacy: a systematic review of interventions for youth aged 15-24

Individuals aged 15-24 years, defined by WHO (2019) as "youth," experience elevated mental health risks, yet most do not access timely support due to barriers including stigma, poor symptom recognition and limited help-seeking confidence. Mental health literacy (MHL) interventions aim to address these barriers, but evidence regarding their effectiveness, delivery modalities, cultural adaptation and methodological quality remains fragmented. This systematic review followed PRISMA 2020 guidelines and examined the characteristics and effectiveness of MHL interventions for youth aged 15-24 across Jorm's (2000) three core domains of recognition, knowledge and attitudes. Five databases (CINAHL, APA PsycArticles, APA PsycInfo, Scopus and PubMed) were searched on 4 September 2024 for randomized and quasi-experimental studies, with narrative synthesis conducted due to heterogeneity and risk of bias assessed using a standardized tool. Twenty-four studies involving 13,624 participants were included. Mental health knowledge improved consistently across interventions and delivery formats, whereas recognition and attitudinal outcomes showed greater variability and were more strongly associated with diagnosis-specific content, contact-based elements and cultural adaptation. Only five studies explicitly reported cultural or contextual adaptation, and eight incorporated positive mental health components, of which only one evaluated positive mental health outcomes. The evidence base was dominated by high-income Western settings, with sparse representation from low- and middle-income countries. Most studies demonstrated moderate-to-high risk of bias, limiting definitive conclusions about efficacy. Overall, youth MHL interventions reliably improve knowledge, but evidence for sustained effects on recognition, stigma reduction and help-seeking remains mixed. Future research should prioritize culturally responsive, developmentally appropriate and methodologically rigorous designs, including systematic measurement of positive mental health outcomes, to strengthen the global evidence base.