often referred to as the Dunedin Longitudinal Study, is a birth cohort study that continues to trace the health and development outcomes of over 1000 people born in 1972 and 1973 in Dunedin, New Zealand. The physical and mental of health of these individuals, along with a wide range of potential risk factors, are still being measured as these individuals near the fourth decade of life. The study has illuminated pathways to antisocial behavior, substance misuse and mental health disorder, and investigated how environmental and genetic factors may influence and interact in the development of problems.