Add Health is a school-based longitudinal study of a nationally-representative sample of adolescents in grades 7-12 in the United States in 1994-95. Data have been collected from adolescents, their fellow students, school administrators, parents, siblings, friends, and romantic partners through multiple data collection components, including four respondent in-home interviews. In addition, existing data bases with information about respondents’ neighborhoods and communities have been merged with Add Health data, including variables on income and poverty, unemployment, availability and utilization of health services, crime, church membership, and social programs and policies. Click on the link for each wave of data collection (at left). The Add Health Research Design PowerPoint provides additional information about study design for Waves I-V.