A Framework to Examine Gateway Relations in Drug Use: An Application of Latent Transition Analysis
Maldonado-Molina, Mildred M., Lanza, Stephanie T., Journal of Drug Issues
A progressive and hierarchical sequence of drug use suggests that a sequence of stages of drug use can describe the order by which adolescents try drugs. We propose an operational definition to test gateway relations by providing a framework with the aim of describing a set of conditions to guide the evaluation of whether a drug serves as a gateway for another drug. We used data from the National Longitudinal Study of Adolescent Health to demonstrate how using latent transition analysis we can estimate the odds of using a drug at a later time conditional on having used a gateway drug at an earlier time. We provide three empirical demonstrations for testing the gateway relations using a national and longitudinal data of adolescents (e.g., gateway relation between cigarettes and marijuana, alcohol and marijuana, and alcohol and cigarettes).
Despite slight decreases in alcohol and tobacco use in recent years, alcohol and tobacco use continues to be a significant public health concern among adolescents (Johnston, O'Malley, Bachman, & Schulenberg, 2009). According to the Monitoring the Future Study, 58.3% of tenth graders have tried alcohol, 31.7% have tried tobacco, and 29.9% have tried marijuana (Johnston et al., 2009). Similarly, according to the Youth Behavior Risk Survey, 74.7% of high school students have ever tried alcohol, 48.8% have tried cigarettes, and 36.9% marijuana (Eaton et al., 2008). Literature concerning the etiology of drug use among youth suggests that legal drugs (e.g., alcohol and tobacco) serve as gateway drugs for illicit drug use. The gateway hypothesis of drug use has been defined as the notion of a progressive and hierarchical sequence of stages of drug use, suggesting an ordered progression of drug use involvement (Kandel, 1 975; Kandel, 2002; Kandel, Yamaguchi, & Cousino Klein, 2006). According to this hypothesis, drug use involvement can be described by a sequence depicting the order by which adolescents try drugs; and the most common sequence starts with legal drugs (either alcohol or cigarettes), which are believed to increase the risk for trying illegal and harder drugs, such as marijuana, cocaine, and heroin.
Kandel provided the first attempt to systematically review what was known about the gateway hypothesis (Kandel, 2002). Specifically, Kandel and Jessor (2002) used three interrelated propositions to summarize current knowledge on the gateway hypothesis (Kandel & Jessor, 2002). First, the sequencing proposition suggests that drug use involvement includes "trying different classes or categories of drugs in an ordered fashion" (Kandel & Jessor, 2002, p. 365). Empirical evidence suggests that the drug use sequence typically starts with alcohol or cigarettes, followed by drunkenness, marijuana, and harder drugs (Collins, 2002; Fergusson, Boden, & Horwood, 2006; Hawkins, Hill, Guo, & Battin-Pearson, 2002; Kandel, 2002; Kandel & Yamaguchi, 2002). Second, the association proposition suggests that the "use of certain drugs is associated with increased risk for other more advanced drugs" (p. 366). Etiological, prevention and intervention studies have provided strong support for this proposition; therefore, many prevention efforts have targeted the reduction of initiation of gateway drugs based on the association proposition by arguing that preventing initiation of legal drugs reduces the likelihood of initiation of other illegal drugs (Botvin, Griffin, Diaz, & Ifil- Williams, 2001; BrettevilleJensen, Melberg, & Jones, 2008; Cleveland & Wiebe, 2008; Degenhardt et al., 2009; Fergusson, et al., 2006; Lessem et al., 2006; Martin, 2003; Rebellón & Van Gundy, 2006; Wagner & Anthony, 2001).
A gap in the literature is that although the term gateway hypothesis is well known, there is no widespread agreement about exactly how to operationalize the gateway hypothesis applied to the study of drug use involvement among adolescents. …