Background: Mental health literacy (MHL) is a relatively ignored determinant of community mental health in Iran, in which its level and determinants should be addressed.

Aim: To investigate MHL and its components among Iranian adolescents.

Methods: A cross-sectional study was conducted. After multistage cluster random sampling, 500 high school students were enrolled. Previously validated Persian version of theMHL Scale (MHLS) was used for data collection. In addition, data on socio-demographic variables were also collected. Adolescents with an MHL score of less than 60% of the achievable score were considered as at-risk of mental health illiteracy. Relevant statistical analyses were used to determine the MHL level and its association with sociodemographic variables.

Results: Overall prevalence of being at-risk of mental health illiteracy was estimated at 71.5 % (95% CI: 67.1, 75.6). Prevalence of being at-risk of stigmatization, inadequate self-help knowledge, and information seeking was 91.2 (95% CI: 88.3, 93.7), 60.3 (95% CI: 59.8, 60.8), and 36.6 (95% CI: 36.1, 37.1), respectively. Having religious beliefs was associated with the stigmatization component (adjusted OR= 2.66, 95% CI: 1.27-5.59).

Conclusions: Prevalence of being at-risk of mental health illiteracy is high among Iranian adolescents. Mental disorders are highly stigmatized in Iran.

Keywords: Mental Health Literacy, Health Literacy, Adolescent, Iran, Mental Disorder