Assessing the relationship between drug use initiation age and racial characteristics

Initiating drug use in adolescence is associated with greater risk of drug misuse and dependence in adulthood and co-occurring mental health disorders. Initiating drug use in adulthood has been linked to higher-risk drug use networks and primary use of "harder drugs". The aim of our research is to examine racial/ethnic differences in age at drug use initiation and its relationship with adult outcomes. Based on data from the 2019 National Survey on Drug Use and Health (NSDUH), we used survey-weighted Poisson regression models with robust variance to identify associations between racial characteristics, age at drug use initiation, and three adult outcomes - past year polydrug use, substance use, and mental illness - adjusting for individual-level characteristics. Among 25,986 respondents who ever used drugs and reported their drug use initiation age, Asian-Americans reported the oldest drug use initiation age (19.5) on average, while Native Americans reported the youngest initiation age (16.6). While there were no significant differences in type of drug used during onset by race or ethnicity, generally, individuals start to use inhalants at the earliest age (17.4), while the misuse of sedatives is initiated at the oldest age (46.4). Initiation during late adolescence was associated with greater likelihood of a substance use disorder diagnosis, mental health diagnoses, and polydrug use in adulthood. Drug use prevention interventions should be tailored and accessible during adolescence to delay onset. Interventions that are culturally sensitive, screen for vulnerability to drug use, and offer age-appropriate services should be prioritized.