The Evidence Is Overwhelming: Cannabis Is an Exit Drug for Major Addictions, Not a Gateway to New Ones

It is time for politicians to put to rest the myth that cannabis is a gateway to the use of other controlled substances — a theory that is neither supported by modern science or empirical data. 

Over 60 percent of American adults acknowledge having tried cannabis, but the overwhelming majority of these individuals never go on to try another illicit substance. Further, nothing in marijuana’s chemical composition alters the brain in a manner that makes users more susceptible to experimenting with other drugs. That’s why both the esteemed Institute of Medicine and the Rand Corporation’s Drug Policy Research Center conclude that "[M]arijuana has no causal influence over hard drug initiation."

In contrast, a growing body of evidence now exists to support the counter notion that for many people, pot serves as a path away from the use of more dangerous substances, including opioids, alcohol, prescription drugs, cocaine, and tobacco.

For example, in jurisdictions where marijuana use is legally regulated, researchers have reported year-over-year declines in opioid-related abuse and mortality. According to data published in the Journal of the American Medical Association, deaths attributable to both prescription opiates and heroin fell by 20 percent shortly after marijuana legalization and by 33 percent within six years. Overall, the study’s investigators concluded, “States with medical cannabis laws had a 24.8 percent lower mean annual opioid overdose mortality rate compared with states without medical cannabis laws.” Data published this past April in the journal Drug and Alcohol Dependence also reports a dramatic decline in opioid pain reliever related hospitalizations following legalization.

Patients’ use of other prescription drugs has also been shown to fall in states where marijuana is legally accessible. Newly published data from both the United States and Canada finds that patients curb their use of anti-depressants, anti-anxiety drugs and sleep aids after initiating cannabis use—a reality that is quantified in their spending habits. According to researchers at the University of Georgia’s Department of Public Policy, Medicare recipients residing in medical marijuana states spent millions less on prescription drugs as compared to patients with similar ailments in non-legal states. Patients’ spending on Medicaid related services is also significantly lower in cannabis-friendly states. 

Emerging data also indicates that pot use is associated with reduced cravings for cocaine. Writing last month in the journal Addictive Behaviors, investigators at the University of Montreal and the University of British Columbia reported that subjects dependent on crack cocaine subsequently reduce their drug use following the intentional use of cannabis. They concluded: “In this longitudinal study, we observed that a period of self-reported intentional use of cannabis … was associated with subsequent periods of reduced use of crack [cocaine]. … Given the substantial global burden of morbidity and mortality attributable to crack cocaine use disorders alongside a lack of effective pharmacotherapies, we echo calla for rigorous experimental research on cannabinoids as a potential treatment for crack cocaine use disorders.”

The findings replicate those of a prior Brazilian study which also determined that the therapeutic use of cannabis mitigates crack cocaine cravings and consumption. 

Empirical data also reinforces this contention. Specifically, Americans’ use of cocaine has fallen dramatically in recent years, during which time the percentage of adults acknowledging using cannabis has risen.

Scientific data also suggests that cannabis may reduce some people’s cravings for alcohol and tobacco. For example, clinical trial data from the United Kingdom finds that subjects administered cannabidiol, an organic cannabinoid, reduces their cigarette smoking by 40 percent compared to participants provided a placebo. Data published earlier this year in the International Journal of Drug Policy reported that over ten percent of Canadian medical cannabis patients acknowledge using pot in lieu of tobacco. 

Survey data from the United States reports even larger declines in cannabis users’ consumption of alcohol. According to a May 2017 study in the Journal of Psychopharmacology, over 40 percent of medical cannabis dispensary members acknowledge reducing their alcohol intake. A 2014 literature review published in the journal Alcohol and Alcoholismadds, “While more research and improved study designs are needed to better identify the extent and impact of cannabis substitution on those affected by AUD (alcohol use disorders), cannabis does appear to be a potential substitute for alcohol.”

Finally, for those seeking treatment for drug dependency, cannabis may also play a positive role. In fact, studies report that pot use is predictive of greater adherence to abstinence among heroin dependent subjects, and those who consume it occasionally are more likely to complete their treatment regimen as compared to those who not.

In light of this scientific evidence, combined with a growing number of Americans’ first-hand experience with cannabis, it is hardly surprising that public confidence in the ‘gateway theory’ is waning. According to survey data compiled in 2016 by YouGov.com, fewer than one in three US citizens agree with the statement, “[T]he use of marijuana leads to the use of hard drugs.” Among those respondents under the age of 65, fewer than one in four agree. Public opinion data provided earlier this week by Yahoo News finds even less support, with only 14 percent of adults expressing “significant concern” that cannabis “leads to the use of other drugs.”

In short, both scientific and public opinion reject the contention that marijuana use promotes the use of other drugs. It’s past time for public officials to renounce this rhetoric as well.