Brazilian High Risk Cohort Study (BHRC)

The Brazilian High Risk Cohort Study for Childhood Psychiatric Disorders (BHRC) is a large community school-based study that is following 2,511 children from Brazil since 2010. We obtained psychological, genetic, and neuroimaging data with the aim to investigate typical and atypical trajectories of psychopathology and cognition over development.

We used a two-stage design. We first assessed childhood symptoms and family history of psychiatric disorders in a screening interview, collecting information from 9,937 index children at 57 schools in the cities of São Paulo and Porto Alegre, as well as from 45,394 family members. In the second stage, a random subsample (intended to be representative of the community, n = 958) and a high-risk subsample (children at increased risk for mental disorders, based on family risk and childhood symptoms, n = 1554) were selected for further evaluation. We evaluated those 2,511 subjects using an extensive protocol, involving one 2-h home evaluation with the parents, two 1-h evaluations of the child by a psychologist, and two 1-h evaluations of the child by a speech pathologist. In those evaluations, saliva samples for genetic studies were collected from the subjects and their biological parents. In addition, 750 children were invited to take part in a neuroimaging study and to provide blood samples for the assessment of peripheral blood biomarkers. Those children were collectively designated the enriched imaging cohort. We just completed our 3-year follow up with 80% retention.