“AS LONG as I am governor of New Jersey, there won’t be legalised marijuana in this state,” vowed Chris Christie, governor of New Jersey, on March 25th. A potential Republican contender in the 2016 presidential race, Mr Christie explained that “every bit of objective data tells us that it’s a gateway drug to other drugs”. Is he right?
A politician claiming “every bit of objective data tells us” should be viewed with suspicion.
The gateway theory seems reasonable enough at first. Most people who take hard drugs start with soft ones. The National Institute on Drug Abuse (NIDA) reports that among people who have tried illicit drugs, about two-thirds began with marijuana. Hardly anyone jumps straight in at the deep end: less than 1% of drug users reported that their first-ever outing was with heroin or cocaine.
But then, it’s also a fact that most heroin addicts had previously tried chocolate. The trouble is that marijuana is so common—about four out of ten Americans, including the president, admit to having tried it—that any abuser of hard drugs is likely to have encountered it along the way. Establishing a causal link is the tricky bit.
The number of marijuana tryers is likely to be higher than that as some people won’t admit to using it (although denials can be genuine – I’ve never tried smoking cannabis, I have an aversion to smoking anything).
Proponents of the “gateway” theory cite two arguments. One is biological: lab rats exposed to THC, the fun bit in marijuana, show greater sensitivity when later exposed to other drugs, such as morphine. Alcohol and nicotine have the same “cross-sensitising” effect. In other words, rats (and perhaps people) that have tried one gently mind-altering substance seem to get more of a kick out of others.
The other argument is social: smoking marijuana, a banned substance, gets youngsters in with the wrong crowd, making them more likely to flout other laws. Breaking one taboo makes it easier to break another. And knowing a marijuana dealer certainly makes it simpler to acquire other substances: drug pushers are notorious for giving free samples of new drugs to their customers.
The first argument is in Mr Christie’s favour. Exposing more people to marijuana, as legalisation probably would, could prime more brains to enjoy other substances. The effect would probably be weak, since those same brains are already exposed to alcohol and tobacco, which have the same sensitising effect. Nonetheless, legalisation would give people another way to mess with their minds. Not everyone would prosper.
But the second argument rather undermines Mr Christie’s position. To the extent that marijuana acts as a social gateway to other drugs, legalisation slams that gateway shut. In Colorado and Washington—and, soon, Alaska and Oregon—marijuana is sold not by drug pushers but by heavily regulated dispensaries, which sell only one drug. The chances of being offered hard drugs under the counter in a Denver pot shop are roughly the same as being offered cocaine along with your beer by a cashier in Walmart.
Drug addiction wrecks people’s lives, but so does too much chocolate, coke, fried food, alcohol and tobacco over time.