Tracking Adolescents' Individtracking Adolescents' Individual Lives Survey ( Trails ) T1 (Baseline) Population Cohortual Lives Survey ( Trails ) T1 (Baseline) Population Cohort

The overall objective of the study is to contribute to the understanding of the determinants of adolescents’ mental (ill-)health and social development during adolescence and young adulthood, as well as the mechanisms underlying the associations between determinants and these outcomes. A particular aim is to focus on the interplay between individual characteristics and environmental factors. In addition to this major objective, a number of participants investigate the course and determinants of somatic (ill-)health, covering topics such as overweight, lung disease, sports, physical activity, and more