PROJECT SUMMARY Neurodevelopmental processes are shaped by dynamic interactions between genes and environments. Maladaptive experiences early in life can alter developmental trajectories, leading to harmful and enduring developmental sequelae. Pre- and postnatal hazards include maternal substance exposure, toxicant exposures in pregnancy and early life, maternal health conditions, parental psychopathology, maltreatment, structural racism, and excessive stress. To elucidate how various environmental hazards impact child development, it is imperative that a normative template of developmental trajectories over the first 10 years of life be established based on a sufficiently large and demographically diverse sample of the US population. To accomplish this, the Healthy Brain and Child Development National Consortium study (HBCD) under the leadership and management of the HBCD National Consortium Administrative Core (HCAC) will deploy a harmonized, optimized, and innovative set of neuroimaging (MRI, EEG) measures complemented by an extensive battery of behavioral, physiological, and psychological tools, and biospecimens to understand neurodevelopmental trajectories in a sample of 7,500 mothers and infants enrolled at sites across the US. The overarching goal of the HBCD is to create a comprehensive, harmonized, and high-dimensional dataset that will characterize typical neurodevelopmental trajectories in US children and that will assess how biological and environmental exposures affect those trajectories. A special emphasis will be placed on understanding the impact of pre- and postnatal exposure to opioids, marijuana, alcohol, tobacco and/or other substances. To address these broad objectives, the HCAC will oversee study design, development of the common protocol, and monitor recruitment and retention to ensure that the sample of women enrolled includes: 1) a racially, ethnically, and socioeconomically diverse cohort that is representative of the US population; 2) pregnant woman with use of targeted substances (opioids, marijuana, alcohol, tobacco); and 3) demographically and behaviorally similar women without substance use in pregnancy to enable valid causal inferences. The HCAC will ensure study objectives are met, monitor performance, provide for training, establish and carry out decision-making and ethical policies, manage all study communications, and oversee processes for considering study modifications. In collaboration with the HBCD National Consortium Data Coordinating Center (HDCC), the HCAC will ensure that approximately annual study datasets are released to the broader scientific community. The HBCD National Consortium study will inform public policy to improve the health and development of children across the nation.

PROJECT NARRATIVE The Healthy Brain and Child Development National Consortium study (HBCD) will follow 7,500 mothers and their children from locations across the U.S. from before birth to 10 years of age to better understand which harmful and protective environments exert the greatest impact on child development. This study will help to improve the health and development of children across the nation. The proposed HBCD National Consortium Administrative Core (HCAC) will provide the leadership and overall management of the consortium to ensure the project’s success.