Add Health is a multidisciplinary multidimensional study that attempted to measure all the domains relevant to the specific developmental stage of the Add Health cohort at the time of the interview, with a particular focus on causes and consequences of health and health behavior. Table 3 shows the general topical areas covered by the survey instruments across waves. The Waves I and II questionnaires collected data relevant to adolescence, including relationships with parents, siblings and friends, academics and school, romantic and sexual relationships, mental health, expectations for the future, and health risk behavior. At Wave III during the transition to adulthood, survey attention shifted toward early family formation, postsecondary education, labor market activity and military service, mentoring, civic participation, while maintaining the longitudinal integrity of previous data on family, friends, achievement, romantic and sexual relationships, physical and mental health, and health behavior. At Wave IV, when the cohort was aged 24-32 and settling into adulthood, more attention was devoted to career development, family formation, social and economic achievement, and early markers of future health risks or conditions. The complete set
