Long-time pot prohibitionist Robert L. DuPont just can’t give up the ghost. The former National Institute on Drug Abuse (NIDA) director and author of the 1985 book Getting Tough on Gateway Drugs took to the New York Times this week to opine, “marijuana has proven to be a gateway drug.” But, as others in the NYT debate room noted, available evidence has long since dismissed DuPont’s scaremongering.
Pot Doesn’t ‘Prime’ The Brain
For starters, DuPont’s claim that early cannabis use “primes the brain” so that those exposed to it at a young age will eventually seek out other illicit substances is not substantiated by clinical evidence. The National Academy of Sciences Institute of Medicine reported over two decades ago, “There is no conclusive evidence that the drug effects of marijuana are causally linked to the subsequent abuse of other drugs.”
More recently, a report issued by the RAND Corporation, entitled “Reassessing the Marijuana Gateway Effect,” affirmed "[M]arijuana has no causal influence over hard drug initiation.” Authors concluded: "While the gateway theory has enjoyed popular acceptance, scientists have always had their doubts. Our study shows that these doubts are justified."
In fact, despite the recent rise in adult use of marijuana in past years, nationwide use of most other illicit substances, particularly cocaine, has fallen dramatically. Further, surveys of cannabis consumers residing in jurisdictions where the plant is legally accessible find that respondents typically report decreasing their use of drugs like alcohol and prescription opiates.
More Pot, Fewer Opiates
Data published in 2014 in the Journal of the American Medical Association (JAMA) Internal Medicine reported that the enactment of statewide medicinal marijuana laws is associated with significantly lower state-level opioid overdose mortality rates, finding,"States with medical cannabis laws had a 24.8 percent lower mean annual opioid overdose mortality rate compared with states without medical cannabis laws.”
Separate data reported by the RAND Corporation in 2015 made a similar conclusion, determining,"[S]tates permitting medical marijuana dispensaries experience a relative decrease in both opioid addictions and opioid overdose deaths compared to states that do not.”
Most recently, statistics compiled this month by Castlight Health, a national employee health benefits platform provider, found that that levels of prescription opioid abuse were nearly twice as high in states that prohibited medical marijuana access as compared to those states that allowed it.
Booze and Cigarettes Come First
As for the claim that cannabis use precedes subjects’ use of other illicit substances, recent research refutes this claim as well.
Writing earlier this year in the Journal of School Health, investigators at Texas A&M University and the University of Florida reported that the use of alcohol and tobacco typically precedes cannabis exposure in poly drug consuming subjects.
“[A]lcohol was the most widely used substance among respondents, initiated earliest, and also the first substance most commonly used in the progression of substance use, the study concluded. “Prioritizing alcohol prevention: Establishing alcohol as a gateway drug and linking age of first drink with illicit drug use.”
A separate paper published online this year in the journal Addictive Behaviors reported that while many teens progress from tobacco to cannabis, comparatively few adolescents try pot and then eventually move on to cigarettes. Finally, data published last week in The American Journal of Public Health reports that adolescent cigarette use is a reliable predictor of later cocaine use.
“Each percent increase (or decrease) in 8th and 10th grade smoking was associated with a … 14 percent to 23 percent increase (or decrease) in prevalence of later cocaine use,” the study found.
Cannabis as an Exit Drug
Rather than being a so-called ‘gateway’ drug, mounting evidence indicates that pot possesses exit drug potential.
Writing late last year in the journal Drug and Alcohol Dependence, researchers at New York’s Columbia University reported a “beneficial effect” of marijuana on treatment retention. “Participants who smoked marijuana had less difficulty with sleep and anxiety and were more likely to remain in treatment as compared to those who were not using marijuana,” the report said.
The findings mimic those of other studies observing that intermittent cannabis consumers are more likely to adhere to their treatment regiment and to complete the outpatient program as compared to those who never used the substance.
Closing the ‘Gateway’
But what about those minority of cannabis users who do go on to use other illicit drugs? Isn’t weed to blame? Not at all.
In fact, in these instances, experts generally identify ‘environmental circumstances,’ not the preceding use of cannabis, as the primary reason why some people transition to other drugs. As acknowledged by the Netherlands Institute of Mental Health and Addiction:
“As for a possible switch from cannabis to hard drugs, it is clear that the pharmacological properties of cannabis are irrelevant in this respect. There is no physically determined tendency towards switching from marijuana to harder substances. Social factors, however, do appear to play a role. The more users become integrated in an environment ('subculture') where, apart from cannabis, hard drugs can also be obtained, the greater the chance that they may switch to hard drugs. Separation of the drug markets is therefore essential.”
Or, to put it another way—permitting marijuana sales to be regulated by licensed, state-authorized distributors rather than by criminal entrepreneurs and pushers of various other, hard drugs would likely result in fewer, not more, tokers trying other illicit substances.