Introduction to the Special Issue on "Informing Longitudinal Studies on the Effects of Maternal Stress and Substance Use on Child Development: Planning for the HEALthy Brain and Child Development (HBCD) Study".

The HEALthy Brain and Child Development (HBCD) study will establish a large cohort of pregnant women from regions of the country significantly affected by the opioid crisis and follow them and their children for at least 10 years. Findings from this cohort will help researchers understand normative childhood brain development as well as the long-term impact of prenatal and postnatal opioid and other drug and environmental exposures. The study will collect data on pregnancy and fetal development; infant and early childhood structural and functional brain imaging; anthropometrics; medical history; family history; biospecimens; and social, emotional, and cognitive development. Knowledge gained from this research will be critical to help predict and prevent some of the known effects of prenatal and postnatal exposure to certain drugs or environmental exposures, including risk for future substance use, mental disorders, and other behavioral and developmental problems. In this special issue, a subset of investigators that received funding for planning grants for the HBCD study provide careful guidelines and frameworks for study design, recruitment and retention of vulnerable populations, culturally sensitive practices, and biospecimen and neurodevelopmental assessment recommendations gathered in feasibility studies that will help inform the full HBCD study planned to begin recruitment in 2022.