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Marijuana And The Gateway Theory

NORML Report, NOV 1996

Since the earliest stages of marijuana prohibition, critics have maintained that one of marijuana's greatest dangers is its potential to be used as a gateway to harder drugs. Currently, this notion serves as one of the key facets of the prohibitionist argument. Ironically, there exists little scientific data to support this theory.

Depending on society's hard-drug of choice throughout the past century, prohibitionists have consistently branded marijuana as the inevitable gateway. For example, marijuana prohibitionist and one of the chief proponents of the gateway theory, Gabriel Nahas, has claimed: "It appears that the biochemical changes induced by marijuana in the brain result in drug-seeking, drug taking behavior, which in many instances will lead the user to experiment with other pleasurable substances. The risk of progression from marijuana to cocaine to heroin is now well documented."[1]

According to much of the scientific literature, however, this assessment could not be further from the truth.

One of the first major studies to debunk the gateway theory was commissioned by New York City Mayor Fiorello La Guardia in 1938. The six year study, conducted by a team of scientists from the New York Academy of Medicine, was the most comprehensive, extensive marijuana fact-finding mission since the Indian Hemp Drug Commission released its monumental approximately 50 years earlier. Released in 1944 as "The LaGuardia Report," the study found that:

"The use of marijuana does not lead to morphine or heroin or cocaine addiction. ...The instances are extremely rare where the habit of marihuana (sic) smoking is associated with addiction to these narcotics."[2][3]

In 1972, President Richard Nixon appointed a panel of politicians and leading addiction scholars to examine federal policy regarding marijuana. The commission, headed by former Pennsylvania governor Raymond P. Schafer, contracted a study of 105 middle class California marijuana smokers to investigate marijuana's alleged gateway potential. According to the commision's findings,

"With the exception of marihuana (sic) and hashish, no drug was used by more than 25 percent of this population and this use was almost exclusively experimental."

This led the commission to conclude that,

"incidence of other drug use was relatively low, [even among] frequent marihuana users."

Regarding the patterns of use among adolescent marijuana users, the commission stated that,

"a majority of [high school marijuana users] have used no other illicit drug, and they tend to be experimental or intermittent users of marihuana (sic)."[4]

The issue of marijuana's purported gateway effect was explored yet again several years later in a federally contracted study for the Center for Studies of Narcotics and Drug Abuse of the National Institute of Mental Health. Directed by Drs. Vera Rubin and Lambros Comitas of the Research Institute for the Study of Man and conducted in Jamaica, the study was hailed as "the first intensive multidiscplinary study of marijuana use to be published."[5] Summarizing the findings of the study in the July 4, 1975 issue of Science Magazine, Dr. Erich Goode of the State university of New York at Stony Brook wrote:

"One of the more interesting findings to emerge from this study relates to the 'stepping-stone' hypothesis. ... Nothing like that occurs among heavy, chronic ganja smokers of Jamaica. No other drugs were used, aside from aspirin, tea, alcohol, and tobacco. The only hard drug use known on the island is indulged by North American tourists."[6]

A fourth federally contracted study reaffirmed this conclusion some years later. Conducted by the Institute of Medicine of the National Academy of Sciences (NAS) and released in 1982, the 15-month study analyzed the habits of American marijuana smokers and offered one of the most comprehensive and balanced analyses ever compiled regarding marijuana and its effects. In regards to marijuana's gateway potential, the study concluded that, "There is no evidence to support the belief that the use of one drug will inevitably lead to the use of any other drug."[7]

Although never fully laid to rest, the much maligned gateway theory returned to prominence in the early 1990s driven by statements made by the Center on Addiction and Substance Abuse (CASA) and it's head Joseph Califano. Armed with statistics from the 1991 National Household Survey on Drug Abuse, CASA announced that marijuana users are 85 times more likely than non-marijuana users to try cocaine. However, as pointed out by NORML board members Drs. John P. Morgan and Lynn Zimmer, this figure is close to meaningless. It was calculated by dividing the proportion of adolescent marijuana users who have ever used cocaine by the proportion of cocaine users who have never used marijuana. The high risk factor is a product not of the fact that so many marijuana users use cocaine, but that so many cocaine users used marijuana previously.[8]

"It is hardly a revelation that people who use one of the least popular drugs are likely to use the more popular ones -- not only marijuana, but also alcohol," noted Morgan.[9]

Perhaps more damning than any other indictment of the "gateway" hypothesis is that it fails to hold up in the face of the federal government's own statistics regarding drug use. For example, as marijuana use increased in the 1960s and 1970s, heroin use declined; while cocaine use was increasing in the early 1980s, marijuana use was declining. Over the past 20 years, marijuana use rates have fluctuated dramatically while the use of hallucinogens has hardly changed at all. Most importantly, federal statistics indicate that although nearly 66 million Americans over age 12 have experimented with marijuana at some point in their lifetime, less than one-third of them have ever tried cocaine.[10] Moreover, less than 16 million Americans admit to having ever experimented with LSD, less than 7 million have ever tried methamphetamines, and only 2.5 million have ever graduated to heroin.[11] In sum, federal statistics conclude that the overwhelming majority of American marijuana users do not move on to harder drugs.

It is worth noting that many scientists and physicians within our own government now dismiss the validity of the "gateway theory." For example, the 1995 guidebook: Marijuana: Facts for Teens, published by the U.S. Department of Health and Human Services (HHS), states unequivocally that, "Most marijuana users do not go on to use other drugs."[12] In addition, similar 1996 literature from the HHS reasons that the minority of marijuana users who do graduate to harder drugs do so not because of marijuana use, but because of marijuana prohibition. "Using marijuana puts children and teens in contact with people who are users and sellers of other drugs," states Marijuana: What Parents Need to Know. "So there is more of a chance for a marijuana user to be exposed and urged to try more drugs."[13]

Further support for this theory is provided by the Netherlands where marijuana is allowed to be purchased openly in government-regulated "coffee shops" designed specifically to separate young marijuana users from illegal markets where harder drugs are sold. As a result, just 1.8 percent of Dutch youth report having tried cocaine and 75 percent of adult cannabis users do not report other drug use.[14][15] Consequently, it seems that when the cannabis markets are effectively separated from the harder drugs, marijuana is clearly a "terminus" rather than a gateway drug.

Although the gateway theory still remains a staple in prohibitionist rhetoric, the facts indicate it to be a blatant falsehood. Moreover, any correlation between marijuana use and hard drug use can be linked to federal policies that place marijuana in the same underground markets as hard drugs like cocaine and heroin. Consequently, politicians who voice concern about marijuana being a possible gateway to harder drugs should review the facts and support policies that would effectively separate marijuana from the black market.


1 Nahas, G. Keep Off the Grass. Paul S. Eriksson, Middlebury, Vermont, 1985.

2 The Marihuana Problem in the City of New York: Sociological, Medical, Psychological, and Pharmacological Studies by the Mayors Committee on Marihuana. The Jaques Cattell Press, Lancaster, Pennsylvania, 1944, p. 25.

3 Ibid., p. 13.

4 Marihuana: A Signal of Misunderstanding: First Report of the National Commission on Marihuana and Drug Abuse. U.S. Government Printing Office, Washington, D.C., 1972, pps. 45-46.

5 Sullivan, Walter. "Marijuana Study by U.S. Finds No Serious Harm." New York Times: July 5, 1975.

6 Goode, Erich. "Effects of Cannabis in Another Culture." Science Magazine: July 1975, pp. 41-42.

7 Marijuana and Health: Report of a Study by a Committee of the Institute of Medicine. National Academy Press, Washington, D.C., 1982, p. 47.

8 Drs. Morgan, John and Zimmer, Lynn. "The Myth of Marijuana's Gateway Effect." NORML's Active Resistance, Spring 1995, p. 9.

9 Ibid.

10 Drs. Morgan, John and Zimmer, Lynn. Exposing Marijuana Myths: A Review of the Scientific Evidence. Open Society Institute, New York City, 1995, p. 14.

11 Preliminary Estimates from the 1995 Household Survey on Drug Abuse. U.S. Department of Health and Human Services. Washington, D.C. August 1996, p. 56.

12 Marijuana: Facts for Teens. U.S. Department of Health and Human Services. Washington, D.C. 1995, p. 10.

13 Marijuana: What Parents Need to Know. U.S. Department of Health and Human Services. Washington, D.C. 1995, p. 11.

14 Drs. Morgan, John and Zimmer, Lynn. Exposing Marijuana Myths: A Review of the Scientific Evidence.

15 Cohen, Peter, et al. Cannabis Use, A Stepping Stone to Other Drugs? 1996.

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