The science of child and adolescent mental health in Brazil: a nationwide systematic review and compendium of evidence

Discussion This systematic review provides a compendium of evidence-based resources on child and adolescent mental health in Brazil. A dataset is made freely accessible to navigate 2576 prevalence estimates, 912 assessment instruments, and 173 intervention trials, facilitating the uptake of resources to practice and offering a wealth of data for scholar research and policymaking. The best data on the prevalence of mental disorders in Brazil comes from regional cohort studies, which estimate that 10.8% to 19.9% of children and adolescents meet clinical criteria for at least one diagnosis.48 49 At the national level, health records reveal suicide rates about 17× times higher among Indigenous youth,50 as well as a 28-fold rise in self-harm notifications among all Brazilian adolescents over the past decade.53 School-based surveys raise concerns about substance use (eg, lifetime alcohol use: 65.2%; e-cigarettes: 17.1%; illicit drugs: 14.3%) and exposure to severe violence (eg, physical assault by a guardian in the past year: 21%; lifetime sexual abuse: 14.6%).54–56 58–62 Some internationally used instruments such as the Development and Well-Being Assessment, Swanson, Nolan and Pelham Scale, and CBCL have been systematically validated, yet most tools lack replication to ensure reliable assessment locally. To date, no community-based intervention has demonstrated effectiveness for large-scale implementation in Brazil. Here, we debate these findings and analyse the current state of national science in this field. Brazil lacks a nationwide prevalence study on child and adolescent mental disorders as have been conducted in the USA and UK.80 81 Best available data estimate the prevalence of mental diagnoses comparable to global figures, usually around 13% for age groups from 7 to 11,48 82–85 yet literature overly represents samples from south and southeast states. Alcohol consumption among Brazilian adolescents is a cause for concern, placing the country in the upper range of multicountry rankings.86 87 The sharp rise in self-harm notifications between 2010 and 2019 is partly attributed to the 2014 policy mandating the reporting of self-harm cases within the Brazilian health system, yet underreporting likely remains.88 While global estimates suggest an upward trend during recent time series, direct comparisons are limited due to differences in assessing self-inflicted injury.89 Brazil’s health surveillance systems stand out in several areas of vital statistics.90 This yields high-quality assessment on suicide mortality, which shows that rates among Brazilian children and adolescents are broadly in line with global estimates,91 yet disproportionately higher among Indigenous youth.50 A similar pattern has been reported for Indigenous peoples globally, including Australian Aboriginal, Māori and Native American groups.91 92 Nevertheless, a substantial paucity of suicide data persists for Indigenous populations. This gap stems from fragile vital statistics systems in the Global South (where the majority of Indigenous people live), and from a lack of ethnic identifiers in national databases of high-income nations such as Canada.92 Consequently, these findings from the Brazilian surveillance system provide a crucial contribution to the epidemiology of suicide among Indigenous groups, particularly youth.92 Despite these insights, our review highlights that research focused on the mental health of Indigenous youth in Brazil remains particularly scarce, reflecting a history of exclusion on health data and statistics.11 Brazil’s burden of sociocultural violence profoundly impacts mental health. Children and adolescents face high rates of severe street, school, domestic and sexual violence, increasing risks of unfavourable mental health outcomes. Systemic racism underlies many of these associations: racial discrimination, poorer living conditions and higher exposure to violence place Black youth at elevated risk for depression, self-harm and substance use. Notably, Brazil has a world-record rate of firearm-related adolescent deaths (10.04 per 100 000), predominantly involving homicides of young Black males.67 These findings add crucial evidence to the emerging debate on the mental health of Black children and adolescents in Brazil,93 supporting calls for intervention programmes that explicitly incorporate anti-racist goals and culturally responsive tools tailored to diverse contexts such as quilombola communities.64 65 69 Public funding is the primary driver of scientific production on child and adolescent mental health. Despite growth, concerns about quality and scope persist. Many widely used international tools lack consistent psychometric and cross-cultural validation, reflecting common challenges in non-English-speaking countries.28 There are no large-scale trials for anxiety, depression, stress or bullying as reported across international literature.94–96 The largest school-based interventions in Brazil have adapted substance-use prevention programmes from European and North American interventions, lacking efficacy. Notably, #TamoJunto 2.0 improved cross-cultural adaptation to mitigate harmful effects on alcohol initiation outcomes reported in #TamoJunto 1.0, suggesting the complexity and risk of cultural adaptation of interventions developed in high-income countries.78 97 Improving research quality also requires addressing major replication issues. This review identified a vast number of mental health publications scattered across a fragmented and uncoordinated body of literature. There were hundreds of duplicated efforts and isolated findings, many only available as theses and dissertations. By appraising and organising this research body, the compendium offers a unified catalogue intended to foster a common language and hopefully optimise resources within the scholarly community. Strengths and limitations This broad-scope review adopts a comprehensive search strategy, encompassing a range of databases, snowballing inclusions, expert consultations and framed search for gaps, without restrictions of time or language. It adheres to evidence synthesis guidelines across three domains, rigorously appraising studies according to established manuals such as Cochrane and COSMIN.40 41 Our database synthesises a substantial amount of data in an accessible manner for consultation, potentially representing the largest compilation effort in this field. We also encountered limitations. To manage the large-scale scope of the review, full-text screening and data extraction were conducted by a single reviewer, with independent accuracy checks limited to a random 20% sample of the dataset. Inclusions from grey literature were not peer-reviewed, compromising the quality of evidence from this datasource. The broadness of scope implies that many studies might not be located. As highlighted in the COSMIN manual,40 capturing all data sources for instruments is challenging, and many translations and validations may exist in sources beyond the reach of our search strategy (eg, books, developer manuals and websites). Works with relevant information were not included due to age-related inclusion criteria, such as the gender dysphoria prevalence studies that do not discriminate information for participants under 19.98–101 Most prevalence and intervention studies also reported information on instruments, potentially overrepresenting the latter’s numbers in the final aggregation. Due to substantial heterogeneity in scope, populations, regions and methodologies, a meta-analysis was not conducted. We only assessed quantitative works. It is important to note that qualitative social and psychosocial research is robust in Brazil and provides culturally sensitive insights to illuminate quantitative exploration.102–105