How the Prevalence of Drug Use and Timing of First Initiation Influence Risky and Protective Behaviors Among Youth in the United States: Assessing Three Decades of Data

Since at least the early 1990s, the United States government and non-governmental institutions have invested significant resources into preventing the use of addictive substances, particularly by adolescents. The U.S. federal government alone spent nearly ½ Trillion dollars between 2012 and 2024 to prevent and reduce drug use. The scientific rationale behind these efforts was a body of correlational evidence that showed that alcohol and marijuana use, particularly early-onset use, were likely “gateways” to numerous more risky behaviors and adverse outcomes. Yet, many prevention efforts tested through experimental trials have produced mixed effectiveness results. It is possible that while drug use is associated with risky behaviors and adverse outcomes, marijuana use, particularly, is not the ‘gateway’ drug that it is purported to be. Drug use and other risky behaviors are potentially co-occurring behaviors all resulting from stressful life events and other adolescent characteristics. Indeed, investigators have not yet examined systemic changes in drug use patterns by youth over time, and how these changes relate to variations in risky behaviors. Using completed surveys of about 250,000 14- to 18-year-old students from a nationally representative sample collected bi-annually between 1991 and 2023, this study aims to address this gap in research by first examining the degree by which prevalence and timing of first substance use vary over time (years). We then assess whether any temporal changes have, in turn, influenced the prevalence of various risk and protective factors once the sample’s demographics are controlled. This latter assessment will examine whether drug use and changes in drug use patterns precede changes in adolescents’ risky behaviors since the ‘gateway’ hypothesis presumes that drug use precedes other risky behaviors.