RESUMEN
The prevalence of mental disorders in adolescents has a considerable impact on daily life, restricting tasks and diminishing overall quality of life while potentially leading to stigmatization. This study aims to measure the impact of a mental health literacy intervention program, called "Bicho de 7 Cabeças" project, in b-learning format, on the increase of knowledge and the decrease of stigma in young people from Póvoa de Varzim, in Portugal. A quasi-experimental study was conducted, from November 2022 to May 2023, involving an experimental group ("Bicho de 7 Cabeças" protocol) and an active control group (informational brochures), utilizing a pre-test/post-test design. Mental Health Literacy Measure-MHLM, Mental Health Promoting Knowledge Scale-MHPK-10, Mental Illness Knowledge Schedule-MAKS, Reported and Intended Behaviour Scale-RIBS, and Community Attitudes toward People with Mental Illness-CAMI were used. A total of 504 young students from the 9th grade enroll in this study, with a mean age around 14 years old. There is a significant difference between stigma (p <.001) and knowledge (p <.001) scores at baseline and follow-up. The results of this study shows that interventions aimed at young people for the promotion of mental health literacy and stigma reduction are needed and more initiatives should be implemented in schools to address these problems.