Health literacy and adolescents' substance use behaviors and correlates: a scoping review

From 2011 to 2023, substance use increased by 23% worldwide. Given that substance use initiation is highest during adolescence, it is crucial to identify amenable correlates of substance use prevention [e.g. health literacy (HL)], which, if embedded in interventions, may improve uptake and outcomes. Hence, this study conducted a scoping review to answer the question: What is known from the existing literature about the relationship between HL and substance use correlates and behaviors in adolescents? Five electronic databases and the bibliography of review articles were searched and a total of 1770 records were identified. After removing duplicates and engaging in three levels of screening to identify studies that included adolescents ≤ 25 years old and assessed the relationship between general HL (vs. behavior/disease-specific health knowledge) and substance use behaviors and correlates, 16 studies were retained. Studies assessed alcohol-related (n = 11), tobacco-related (n = 12), electronic vapor product use-related (n = 4), cannabis-related (n = 1), and amphetamines/methamphetamines-related (n = 1) outcomes. Studies spanned Africa, Asia, Europe, and North and Central America. Most studies included substance use as an outcome and found an inverse relationship between HL and use. Few studies examined substance use correlates (e.g. risk perception). There were no longitudinal or intervention studies. This review highlighted that the topic of adolescent HL and its relationship with substance use remains inadequately researched. Notable gaps for future studies include intervention and longitudinal designs, expansion of outcomes (e.g. more studies on marijuana, prescription drug misuse, vaping, substance use-related correlates), and examining HL as a mediator or moderator of substance use and its correlates.