Objective: This study aims to describe the design, methods and sample characteristics of the Multidimensional Evaluation and Treatment of Anxiety in Children and Adolescents -the PROTAIA Project. Method: Students between 10 and 17 years old from all six schools belonging to the catchment area of the Primary Care Unit of Hospital de Clínicas de Porto Alegre were included in the project. It comprises five phases: (1) a community screening phase; (2) a psychiatric diagnostic phase; (3) a multidimensional assessment phase evaluating environmental, neuropsychological, nutritional, and biological factors; (4) a treatment phase, and (5) a translational phase. Results: A total of 2,457 subjects from the community were screened for anxiety disorders. From those who attended the diagnostic interview, we identified 138 individuals with at least one anxiety disorder (apart from specific phobia) and 102 individuals without any anxiety disorder. Among the anxiety cases, generalized anxiety disorder (n = 95; 68.8%), social anxiety disorder (n = 57; 41.3%) and separation anxiety disorder (n = 49; 35.5%) were the most frequent disorders. Conclusion:The PROTAIA Project is a promising research project that can contribute to the knowledge of the relationship between anxiety disorders and anxiety-related phenotypes with several genetic and environmental risk factors. Resumo Objetivo: o objetivo deste estudo é descrever o desenho, os métodos e as características amostrais da Avaliação Multidimensional e Tratamento da Ansiedade em Crianças e Adolescentes -Projeto PROTAIA. Método: Escolares entre 10 e 17 anos de todas as escolas pertencentes à área de abrangência da unidade de atenção primária do Hospital de Clínicas de Porto Alegre foram incluídos no projeto. O projeto compreende cinco fases: 1) triagem comunitária; 2) diagnóstico psiquiátrico; 3) avaliação multidimensional, incluindo fatores ambientais, neuropsicológicos, nutricionais e marcadores biológicos; 4) tratamento; e 5) fase translacional. Resultados: Um total de 2.457 sujeitos foram triados para transtornos de ansiedade na comunidade. Dos indivíduos que compareceram à avaliação diagnóstica, 138 foram detectados com ao menos um transtorno de ansiedade (excluindo fobia específica) e 102 indivíduos sem nenhum transtorno de ansiedade. Dentre os casos de ansiedade, o transtorno de ansiedade generalizada (n = 95; 68,8%), transtorno de ansiedade social (n = 57; 41,3%) e o transtorno de ansiedade de separação (n = 49; 35,5%) foram os mais frequentes. Conclusão: O projeto PROTAIA é um projeto de pesquisa promissor que pode contribuir para o entendimento da relação entre transtornos de ansiedade e fenótipos relacionados à ansiedade com vários fatores de risco, tanto genéticos quanto ambientais.

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Different lines of evidence support BDNF as a candidate gene in mood and anxiety modulation. More recently, the Met allele of the BDNF Val66Met polymorphism has been implicated in anxiety in animal models and anxiety-traits in humans. The aim of this study is to evaluate the a priori hypothesis that the association between anxiety disorders and Val66Met polymorphism at the BDNF gene would be replicated in a community sample of children and adolescents. 240 subjects from a total sample of 2457 children and adolescents aged 10-17 years from the public schools in the catchment area of the primary care unit of a university hospital participated in this case-control study and were assessed for psychopathology using the K-SADS-PL. A sample of saliva was collected for DNA analysis of Val66Met polymorphism. BDNF was the single gene evaluated in this sample. We found a significant association between carrying one copy of the Met allele and higher chance of anxiety disorders in children and adolescents. The association remained positive even after the adjustment for potential confounders (228 subjects; OR=3.53 (CI95% 1.77-7.06; p<0.001)). Our results support the a priori hypothesis of an association between anxiety and the polymorphism Val66Met. To our knowledge, this is the first study documenting a potential role of this polymorphism in a community sample of anxious children and adolescents.

Evidence on the relationship between genetics and mental health are flourishing. However, few studies are evaluating early biomarkers that might link genes, environment, and psychopathology. We aimed to study telomere length (TL) and epigenetic age acceleration (AA) in a cohort of adolescents with and without anxiety disorders (N = 234). We evaluated a representative subsample of participants at baseline and after 5 years (n = 76) and categorized them according to their anxiety disorder diagnosis at both time points: (1) control group (no anxiety disorder, n = 18), (2) variable group (anxiety disorder in one evaluation, n = 38), and (3) persistent group (anxiety disorder at both time points, n = 20). We assessed relative mean TL by real-time quantitative PCR and DNA methylation by Infinium HumanMethylation450 BeadChip. We calculated AA using the Horvath age estimation algorithm and analyzed differences among groups using generalized linear mixed models. The persistent group of anxiety disorder did not change TL over time (p = 0.495). The variable group had higher baseline TL (p = 0.003) but no accelerated TL erosion in comparison to the non-anxiety control group (p = 0.053). Furthermore, there were no differences in AA among groups over time. Our findings suggest that adolescents with chronic anxiety did not change telomere length over time, which could be related to a delay in neuronal development in this period of life.