NIH Message
On March 31, 2025, as a sponsor of this project, NIH requested that the following language be added to this website: This repository is under review for potential modification in compliance with Administration directives.
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The National Longitudinal Study of Adolescent to Adult Health (Add Health) is a longitudinal study of a nationally representative sample of over 20,000 adolescents who were in grades 7-12 during the 1994-95 school year and have been followed for six waves of data collection to date, most recently in 2022-25.
