The average age of first use of illicit drugs is during late adolescence to early adulthood,1 making adolescence an important developmental stage for education and interventions to prevent substance use and disorders.1,2 In particular, earlier age at initiation and patterns of substance use in adolescence may have a lasting influence on substance use and disorders across the life course.3,4 In order to develop and provide effective drug prevention programming to youth, it is necessary to identify adolescents at particularly high risk for illicit drug use5,6 and to investigate the factors that create this higher risk.
