Gateway Drugs

The term gateway drugs suggests that low-classified drugs are precursors to use of addictive and dangerous “hard” drugs. This theory originated in 1975 as a response to concerns that cannabis use leads to the use of harder drugs, such as heroin and cocaine. Leading gateway theorists statistically substantiated the relationship between marijuana and the use of other illegal drugs as well as the relationship between the use of licit drugs (alcohol and cigarettes) and illicit ones (marijuana and cocaine). The researchers found that licit drug use of either alcohol or cigarettes precedes the use of marijuana, and marijuana use precedes the use of other illegal drugs. The identification of this pattern led to the designation of alcohol, cigarettes, and marijuana as “gateway” drugs.

Determining the order in which respondents used the drugs (the sequencing of drug use) was an important aspect of these studies, as it positioned the use of drugs that appear early in the sequence as causal factors to further drug use. However, many other analysts challenge that causal presumption. An association does not mean cause. To illustrate, most bank robbers drink coffee and smoke cigarettes, but this does not mean that caffeine and nicotine cause robbery.

In two follow-up studies of this cohort in 1984 and 1992, the researchers found that the proportion of men and women (in the sample) who had used illicit drugs increased by 30 to 50 percent respectively, substantiating their general findings that drug use is progressive and that initiation into the use of gateway drugs might lead to a lifetime of drug use. The authors found that the age of initiation to gateway drugs was related to further progression of drug use. Men and women who first consumed alcohol or cigarettes at the age of 14 or under remained at that stage in the progression as compared with those who were initiated at age 16 or over, substantiating the progression thesis of the scientists. The extent of drug use in the early part of the progression was also correlated to the rate of drug use later in the respondents' lives. Furthermore, the [Page 390]researchers found that males were more likely to use alcohol before cigarettes and marijuana, and women were more likely to use either alcohol or cigarettes before marijuana. Alcohol played a greater role for men in the progression. The use of medically prescribed drugs followed the delineated sequence. Over 60 percent of respondents who used medically prescribed drugs used legal and illegal drugs at least 10 times in their lifetime.

In contrast, a 12-year University of Pittsburgh study released in 2006 challenged the findings of gateway theorists by revealing that the sequential progression of the gateway hypothesis was inconsistent in a population of 214 boys, ages 10 to 12. The researchers found that a significant number of the young boys used harder, more dangerous drugs before they smoked marijuana or smoked cigarettes or drank alcohol. Because each stage of drug-use progression in the gateway theory hypothesis is a component of both a temporal and a hierarchical sequence, the University of Pittsburgh study challenged the causal relationships between licit and illicit drugs as well as the hysteria surrounding the smoking of marijuana. As part of their study, the researchers compared a set of boys who had followed the gateway sequence (used tobacco or cigarettes first and then used marijuana) with a set of boys who followed a reverse sequence (used marijuana first and then smoked cigarettes or drank alcohol) and found no relationship between either of these patterns and the development of a substance abuse disorder. In other words, neither of these patterns can predict the probability of continued drug use. Instead the researchers hypothesized and statistically proved that environmental factors, such as drug availability in the neighborhood, and individual factors, such as a predisposition for delinquency, play critical roles in the progression toward substance abuse. The boys were compared on 35 variables measuring psychological, family, peer, school, and neighborhood characteristics. Given the fact that gateway theory has strongly influenced anti-drug policies and informed clinical approaches to drug prevention in the United States, the findings of the University of Pittsburgh study shift away the focus from marijuana as a gateway drug and toward a behavioral and structural approach focusing on early socialization, individual and familial predisposition, and neighborhoods as precursors of a lifetime of drug abuse.

...