Drugs and Society – The “Gateway” Theory of Drug Use
Numerous studies of adolescent drug use have shown that there is a typical sequence of use,’such that teenagers or preteens usually use alcohol and/or cigarettes before trying marijuana. Some of these studies further indicate that almost all adolescents who become involved with illicit drugs other than marijuana don’t start with those drugs, but instead begin with alcohol or cigarettes and then marijuana. Results from one representative study are illustrated in the table.The data were obtained from a sample of 1108 twelfth-grade students (540 males and 568 females) attending public or private schools in New York State in 1988. It is readily apparent that within this subject population, alcohol and cigarettes tended to be used first,followed by marijuana, and then by cocaine. Initial use of crack cocaine occurred either after other forms of the drug (that is, powdered cocaine) or sometimes at the same time (Kandel and Yamaguchi, 1993).
Findings such as these have led to the “gateway”theory of adolescent drug progression. According to this theory, individuals who drink or smoke cigarettes are at increased risk for going on to marijuana use, and marijuana use in turn raises a person’s risk of trying other, more dangerous substances such as cocaine.Thus, alcohol and cigarettes are “gateways”for marijuana, and marijuana is a gateway for other illicit drugs (Kandel et al., 1992).
Pairwise Comparison of the Order of Age of Initiation for Five Classes of Drugs among Twelfth Graders Who Used Both Classes of Drugs
|Drug A||Drug B|
Proportion of Specified Ordering
|Drug A before B|
! Drug B before A
Source: From Kandel and Yamaguchi, 1993.
Because of its apparently strong experimental support, the gateway theory has become widely accepted by many researchers, counselors, and drug policy makers. A massive effort has been made to reduce adolescent use of proposed gateway drugs (for example, the DARE Program), in the hope that this , .:l diminish the number of people who later become dependent on substances such as cocaine or heroin. However, objections to the gateway theory can be raised on at least two different grounds. First, the studies upon which the theory is based have been carried out mainly using school surveys.The majority of drug users in a typical high school are probably occasional rather than heavy or”hard-core” users, particularly if we focus on illicit drugs other than mari-juana.This is not only because hardcore users represent a relatively small percentage of the adolescent population, but also because these individuals often drop out of school.
Since many of the destructive effects of drugs on our society arise from hard-core use, we need to ask whether a progression from alcohol and cigarettes to marijuana and then beyond is characteristic of heavy drug users.Two studies of serious drug abusers in New York City have addressed this question. In one study of 994 subjects, most of whom had used cocaine and other illicit substances, marijuana use reliably occurred before that of cocaine or other”hard”drugs. However, in contrast to the prediction of the gateway theory, marijuana was often the first substance used, even before alcohol (Golub and Johnson, 1994). Another study carried out on 233 regular cocaine and heroin users found that the standard progression of alcohol to marijuana to”hard”drugs was true for only 33% of the subjects (Mackesy- Amiti et al„ 1997).The remainder showed several different patterns, sometimes starting with alcohol,then proceeding to illicit drugs other than marijuana and then marijuana (17%); or starting with marijuana before any other drugs (28%); or even starting off with other illicit drugs and then later taking up marijuana and alcohol (22%).These findings suggest that the standard gateway theory may not be a good predictor of the progression of drug use for many people who go on to become hard-core users.
Second, even if we stick to the adolescent population usually considered in the gateway theory, the causal relationships implied by the theory are difficult to prove. It may be the case, for example, that most adolescent cocaine users tried marijuana first. But merely demonstrating this fact is far from proving that the marijuana use somehow caused the individual to progress to cocaine, particularly since most adolescent marijuana users do not progress to more-addictive substances. Indeed, Morral and coworkers (2002) found that the relationship between marijuana use and progression to hard drugs could be accounted for by a common factor they called drug use propensity, which refers to the tendency to use both marijuana and other illicit drugs. Other researchers have proposed a more general alternative to the gateway theory termed either the common syndrome theory or the problem behavior theory. According to this idea, certain adolescents exhibit a number of problem behaviors, such as delinquency, sexual promiscuity, misconduct, parental defiance, and sub-stance use, all of which “reflect a single, underlying factor” (Donovan and Jessor, 1985).This proposed personality factor would increase an individual’s likelihood of experimenting with more-addictive substances.
Furthermore, the observed progression that is usually taken as support for the gateway theory might be due to differences in availability and perceived risk. Even though alcohol and cigarettes cannot be purchased legally by minors, they are nevertheless readily available and are often considered harmless by young people. Likewise, marijuana is more easily obtained than drugs like cocaine and heroin, and its use would be considered less risky. Finally, as individuals exhibiting problem behaviors move through their teenage years into late adolescence and young adulthood, they may develop a belief that taking riskier substances is necessary to demonstrate their newfound maturity.
In summary, there is a well- described progression of substance use among adolescents, although this pattern may differ somewhat for those who eventually become serious drug abusers.The gateway theory proposes that initial use of alcohol and/or cigarettes increases an adolescent’s risk of progressing to marijuana and that marijuana use is a risk factor for”hard”drugs such as cocaine and heroin. Yet it remains to be demonstrated that there is a causal connection involved in the progression of drug use. Moreover,there are alternative approaches such as the problem behavior theory that may be able to account for a progression of drug use without one substance serving as a gateway for another.