BackgroundBrazil is home to 50 million children and adolescents, whose mental health needs require context-sensitive research. Although scientific output is growing in the country, publications are scattered and often inaccessible. <BR><BR>MethodsThis systematic review compiles prevalence estimates, assessment instruments, and interventions for child and adolescent mental health in Brazil (PROSPERO registration: CRD42023491393). We searched international (PubMed, Web of Science, PsycINFO, Google Scholar) and national (Scielo, Lilacs, Brazilian Digital Library of Theses and Dissertations) databases up to July 2024. Reference lists, reviews, and experts were consulted. Extraction followed Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) and Cochrane manuals. <BR><BR>ResultsThis review appraises 734 studies on 2,576 prevalence estimates, 908 studies on 912 instruments, and 192 studies on 173 intervention trials. Point prevalence of any mental disorder ranged from 10.8% (age 12) to 19.9% (ages 7 to 14), although a nationally-representative study is lacking. There is a rise of self-harm notifications, reaching 133.1 in 2019 (per 100,000 aged 10-19). Indigenous youth face suicide rates of 11 (age 10 to 14), far exceeding national averages (0.652). There is severe violence exposure (21% of adolescents reported domestic physical violence in the previous month), disproportionately impacting Black youth and heightening risks for depression and substance use. Reliable instruments exist for assessing psychopathology, yet most lack psychometric and cross-cultural validation. Interventions remain under-implemented; the largest trials adapted international substance-use prevention programs, showing null effects. High-quality studies are mainly funded by public investment. <BR><BR>DiscussionThis compilation provides accessible data for professionals, facilitating translation of science to practice. Brazilian sociocultural challenges impact youth mental health, with public health priorities including violence, systemic racism, and indigenous youth suicide. National research must develop culturally-sensitive resources for mental health, including scalable interventions focused on social minorities. <BR><BR>FundingThe Stavros Niarchos Foundation.
