AddHealth is an ongoing, nationally representative study of adolescents followed into adulthood in the US. In 1994–1995, participants were selected from a stratified sample of 132 schools, resulting in an initial sample of n=90,118 students in grades 7–12. A subset of the original sample (n=20,745) was selected for additional in-home interviews (Wave I/age 11–18 to Wave 5/age 35–42), with a total of n=15,159 individuals providing samples for genotyping at Wave IV. All participants provided informed consent/assent, and the study was approved by the corresponding university Institutional Review Board. Full details on data collection have been previously published (30). The current study includes n=5,107 unrelated EUR participants.
