Like an annoying uncle who seems to keep coming back again and again, the “gateway theory”—that using cannabis makes people more likely to use harder drugs—just won’t seem to go away. This is despite the fact that research shows the vast majority of marijuana users do not go on to use hard drugs.
Correlation, scientists often remind us, isn’t the same thing as causation. If marijuana caused other drug use, the abuse of hard drugs would have risen along with that of weed, and that hasn’t been the case.
Advocates note that cannabis has actually been shown, in many cases, to help prevent people from abusing other substances such as opioids. Some modern drug rehab counselors, in fact, encourage their clients to use marijuana as an “exit drug.” Even DARE now acknowledges that the overwhelming majority of pot smokers never go on to pills and powders.
Argument Against Cannabis Reform
Still, The New York Times recently heralded a “comeback” for the gateway drug theory, which was first popularized by Dr. Robert L. DuPont, Jr., in 1984, during Ronald Reagan’s War On Drugs.
It seems that political demagogues such as Attorney General Jeff Sessions and New Jersey Gov. Chris Christie have routinely trotted out the now-discredited gateway theory as a chief argument against cannabis law reform.
Ironically, the latest research indicates that it isn’t marijuana that’s a gateway; it’s alcohol and nicotine.
A Columbia University study published in November showed rats exposed to alcohol are much more likely than other rats to push a lever giving them a dose of cocaine. Researchers found that alcohol suppresses two genes that normally act as cutoff switches for cocaine’s effects, creating a “permissive environment” for coke in the rats’ brains.
Another study from 2011, performed by some of the same researchers, produced comparable findings using nicotine and mice.
Cannabis: Exit From Opioids?
Cannabis appears to actually lower opioid usage. A 2008 paper found that chronic pain sufferers can reduce their doses of pain-relieving opioids by using marijuana. Even people who combine marijuana with prescription opioids for pain control aren’t more likely to abuse alcohol or other drugs, research has shown.
Japan’s experience casts even more doubt on the gateway theory. In Japan, where cannabis use is far less prevalent than in most Western nations, 83 percent of hard drug users didn’t start out smoking weed, according to a 2010 study. The best evidence we have is that social factors such as poverty and poor environment are greater predictors of hard drug use than is early exposure to marijuana.
The Institute of Medicine of the National Academy of Sciences, in a 1999 report on “the dangers of medical marijuana” for Congress, declared “there is no conclusive evidence that the drug effects of marijuana are causally linked to the subsequent use of other illicit drugs.”
Opioid overdose deaths have, in fact, gone down in states that have legalized cannabis for medicinal purposes.
As Newsweek noted in 2015, “[A]nyone who actually talks with problem drugs users (and doesn’t simply talk about them) knows that marijuana can help drug users prevent, control—even stop—hard drug use.”
Even the DEA Has Given Up On Pushing the Gateway Theory
In a telling move, even the Drug Enforcement Administration (DEA) quietly removed material from its website earlier this year about cannabis as a gateway drug, reports The Hill.
That happy sign of progress, however, doesn’t eclipse the unhappy fact that Atty. Gen. Sessions, a staunch supporter of the DEA, uses his unscientific opinions about marijuana to justify his opposition to cannabis law reform.
Sessions actually mentioned the gateway drug theory in a 2014 Senate Judiciary Committee oversight hearing:
“Lives will be impacted, families will be broken up, children will be damaged because of the difficulties their parents have, and people may be psychologically impacted the rest of their lives with marijuana. And if they go on to more serious drugs, which tends to happen, and you can deny it if you want to, but it tends to happen, there will be even greater (consequences).”
According to the Drug Policy Alliance, research simply doesn’t support Sessions’ claims that cannabis leads to more serious drug use.
“Allowing Mr. Sessions to make law enforcement decisions based on biased, out-of-date information does a tremendous disservice to ASA’s members and the American people at large,” said the legal counsel for Americans for Safe Access, a pro-medical marijuana group.