Marijuana and Teens

Recent surveys, both in Canada and the US, have documented a dramatic rise in marijuana use among adolescents since 1992. This increase has caused much official consternation, and after four years of relative silence on the issue the Clinton administration is mounting a new, 195 million dollar media campaign against drugs, with adolescent marijuana use a major focus.

Teens, it turns out, don't seem particularly worried about pot. The rise in the number of young people who have tried marijuana over the last five years has been accompanied by a decline in the risk they perceive of smoking it occasionally. Meanwhile, the use of hard drugs such as cocaine and heroin has stayed far below that of marijuana, and adolescents perceive these substances as far more risky to use than pot.

Perhaps teens recognize what the National Institute on Drug Abuse (NIDA) has been at pains recently to deny: that there are valid distinctions between soft and hard drugs in addictiveness and potential for harm, and that such distinctions can inform one's choice of psychoactive substance. Occasional use of marijuana is perceived by many, mostly older, adolescents as no more harmful than using alcohol or tobacco.

Teens, in short, are not stupid, and in this case their perceptions are pretty much on the mark. Although certainly not risk free (few psychoactive substances are), marijuana compares favorably to alcohol and tobacco with regard to health hazards and potential for abuse. Consequently, the attempt to tar it with the same brush as cocaine and heroin simply backfires, undercutting the credibility of both NIDA and beleaguered parents, who are asked to instill fear of the "evil weed" into their increasingly skeptical children.

Much is made of pot being a gateway drug which leads to further experimentation and addiction, but as even NIDA admits, most of those who try marijuana don't progress to other drugs or become addicts. Except for powerfully reinforcing drugs like cocaine, heroin and methamphetamine, it's not the particular substance one encounters that usually leads to abuse. Rather, it's a combination of risk factors - parents' and peers' substance use, poor social adjustment, low expectations of achievement, and idle after school hours - which increase the probability of abuse and dependence. If marijuana is a gateway to hard drugs at all, it is most likely due to its illicit and counter-cultural status: the purveyors of pot can put your adolescent in touch with the local crack connection, while the glamour of defying the ban on marijuana may transfer to using more dangerous substances.

None of this is to deny that using marijuana has its risks and long term effects, and its use by developing adolescents should therefore remain illegal and be strongly discouraged. As the disastrous health consequences of cigarette smoking make clear, the psychoactive ingredient of marijuana, delta-9-tetrahydrocannabinol (THC), would best be ingested without inhaling the carcinogenic byproducts of a burning plant. (Marijuana may actually be worse than tobacco in this respect.) While not nearly as devastating as chronic alcoholism, the regular and prolonged use of THC may compromise short term memory and perhaps other cognitive functions, and preliminary research, although by no means definitive, has also implicated THC as an immune system suppressor. Even though non-smoked THC is approved for medical purposes, and thus has been found safe and effective for some applications, its recreational use (as for alcohol and nicotine) should remain occasional, and restricted to those over 21. Pregnant women should avoid it, and the penalties that now apply to drunk driving should also apply to those who drive under the influence of THC.

Despite its bad official press, THC actually ranks lowest in addictive potential of all commonly used substances, even below caffeine, according to two independent ratings by NIDA and the University of California. Lab animals cannot be induced to consistently self-administer THC, as they can with opiates, amphetamines, cocaine, alcohol and nicotine. Nevertheless, NIDA has made much of recent research, published in the journal Science, showing that cannabis acts on the same reward mechanisms in the brain as do other drugs. Rats given large and regular doses of THC or a synthetic equivalent showed withdrawal symptoms when doses were abruptly stopped. But this rather unsurprising result, which holds for alcohol and nicotine as well, doesn't show THC to be especially problematic, just that its heavy use may in some cases lead to habituation. The fact remains that marijuana is simply not in the same class as heroin and crack, drugs which act far more powerfully and specifically on those brain sites implicated in dependence. This means that its increased availability following decriminalization for adults would not result, as some fear, in an epidemic of cannabis abuse.

The best argument, perhaps, for keeping marijuana illegal across the board is that we simply don't need another widely available intoxicating substance, however benign, which might deflect adolescents from the necessary business of putting their lives together. But the horse is already well clear of the barn. In recent surveys many teens say that it's nearly as easy to get marijuana as alcohol and cigarettes. Drug enforcement hawks will reply that this means stricter sanctions are necessary, but how strict are we willing to get to suppress a drug that, used in moderation and in a non-smoked form, is no more risky (subtracting the risks of criminal prosecution) than having an occasional glass of wine with dinner?

Such policy questions should be addressed while keeping in mind the contingent history of our relationship with psychoactive substances. Since things could have turned out quite differently, we shouldn't suppose that our current legal selection of drugs is ultimately correct. Marijuana, not tobacco, might have become the fashionable ingredient for cigarettes in European salons, and alcohol might now be illegal had prohibition survived. What then drives the ideology that would forbid any marijuana use, and that absurdly classifies it with much more dangerous substances?

Some opponents of decriminalizing marijuana fear that it would set us on a slippery slope toward accepting any and all drugs, but this fear is irrational precisely because all drugs are not the same. We justly balk at sanctioning the use of substances that are highly addictive and harmful, as in the growing effort to curtail tobacco sales to minors. Other opponents, most of them hardly teetotalers, share the conventional prejudice that getting high on pot is somehow morally suspect. They suppose that some intoxicants (the currently legal ones, it just so happens) are fine while the rest are corrupting, and that therefore we shouldn't expand our repertoire of even mildly altered states. But if the effects of alcohol, nicotine and caffeine used in moderation are perfectly acceptable, why not those of THC, used in moderation?

Some will object that moderation in the use of marijuana is exactly what cannot be guaranteed; that decriminalizing pot for adults would inevitably increase the number of users (some teenagers included) that abuse the drug and fall prey to its possibly damaging long-term effects. Granting this point, the issue then becomes whether the social and personal benefits of lifting the ban on marijuana outweigh the harms of a potential increase in abuse.

This is exactly parallel to the dilemma faced by those who wanted to end alcohol prohibition: since prohibition helped to reduce alcohol-related addiction, disease and accidents, how could one responsibly advocate its repeal? Nevertheless, prohibition ended when it became clear that the personal liberty to enjoy alcohol, restrained by reasonable public health and law enforcement safeguards, was deemed a greater good than heavy-handed attempts to reduce alcohol-related harms. Similarly, it is difficult to justify the staggering costs of the marijuana ban - the person-hours of drug enforcement, the ultimately futile attempts at crop eradication, the overloaded courts, and the draconian jail sentences - when weighed against the small increase in abuse that decriminalization for adults might entail. If we want proportionality between the sanctions against a drug and its potential for harm, then criminal penalties for personal marijuana use should be abolished.

If we fail to reconsider our current policy, and continue to exaggerate the evils of any and all cannabis use, teenagers will judge adults hypocritical and continue to light up joints as they chant "Just say no!". A better course would be to introduce teens to the responsibilities, pleasures and risks of adult life by informing them accurately about drugs and addiction, just as we do (or should do) for sexuality, diet, exercise and careers. A scientifically grounded consideration of psychoactive substances, unclouded by the prohibitionist reflex, will show THC, like alcohol, to be comparatively harmless when used responsibly by adults. By being straight with kids, and ourselves, about pot's active ingredient, we'll gain credibility and strengthen the case against truly dangerous and addictive drugs. If we respect our children's intelligence, the chances are they'll behave more intelligently.

In our public health campaigns we should vigorously advise against smoking marijuana, while exploring safer means of ingesting recreational THC which standardize a moderate dose and guarantee purity. As with alcohol and nicotine, we should limit its availability to adolescents by establishing a minimum age for possession, enforced by appropriate sanctions. Use of THC by adults could be regulated by prohibiting any sales or public consumption, with civil penalties - not jail sentences - for infractions. Whatever course we adopt, there are clearly many policy options short of commercial legalization that would improve upon the absurdly punitive status quo. There would, of course, be many devils in the details of regulating decriminalization, but none nearly as onerous as our foolish obsession with attaining a cannabis-free culture.

Even with the most enlightened policies, some cannabis use by teens will inevitably continue, but we won't be denying them the drug on the spurious basis that there is something especially bad about THC. We'll be denying it for the same good reasons we deny them nicotine, alcohol, or any other psychoactive substance: successful physical and psychological maturation is jeopardized by adolescent drug use, and at their age they've got more important things to do, such as fashioning a life that doesn't revolve around looking cool or getting high.

©   Thomas W. Clark

The Gatekeeper Hypothesis

(Open letter to Alan Leshner, director of the National Institute on Drug Abuse)

Dear Alan,

You’re the head of the National Institute on Drug Abuse (NIDA), which prides itself on supporting "more than 85% of the world’s research on the health aspects of drug abuse," according to a recent press release. You’ve got clout, and use it to push the image of NIDA as an organization wedded to science, altruistically seeking the causes and cures of addiction. Me, I work in relative obscurity at a private firm in Boston which gets funding from the state to conduct applied research and evaluation on substance abuse. I’ve also been a member for the last five years of the NIDA’s Community Epidemiology Work Group (CEWG), a twenty city consortium of researchers that tracks illicit drug use trends in the U.S.

Until recently, you didn’t know that. No reason you should, after all. While you’ve been heading up NIDA, I’ve been conducting local surveys and focus groups on adolescent substance use, with occasional getaways to CEWG conferences. I was just a face in the crowd you addressed at our 1997 meeting in Washington.

But now you’re at least dimly aware of my existence, and therein hangs a tale. Our lives intersected when the Boston Globe published a Sunday opinion piece of mine on decriminalizing marijuana. I took the position that marijuana used in moderation by adults is, from a health standpoint, no more dangerous than using alcohol and tobacco, and that NIDA’s refusal (along with most of the official establishment) to admit as much undercuts its credibility. If you want to impress kids with the dangers of drug use, hyperventilating on the evils of pot is not the way to go. I never suggested that it’s harmless, mind you, or that adolescents be allowed to smoke it. Only that if one wants proportionality between the sanctions against a substance and its danger to life and limb, the prohibition against the private consumption of cannabis by adults should be lifted.

For NIDA, as well as state health departments, all this is anathema, of course, so as the article went to press I wondered nervously what sort of fire it would draw. Would I lose my job? (No, I’m still gainfully employed.) Would my firm’s funding from state and federal sources be cut in retaliation? (No, and such retaliation, could it be proved, is of course actionable.) Would someone like White House drug policy chief Barry McAffrey or you, Alan, weigh in with a reply?

Indeed you would. Three weeks to the day after the article appeared, your letter appeared in the Globe, the heavy guns brought to bear in defense of NIDA orthodoxy. Most of it was predictable enough. You said "marijuana is a drug with a high potential for abuse" that leads many people to seek treatment, that it affects "learning, memory, emotional state, perception, and the motor skills necessary to drive a car," and that its long term use can affect the lungs and immune system.

Although the first of these claims is certainly arguable, especially when comparing pot to alcohol and nicotine, and the evidence for immune system damage is equivocal at best, I won’t debate these points here because another of your assertions is the crux of my concern (and now yours, I hope). You said, and I quote in full, with emphasis added: "Another science-based reason for not condoning marijuana use comes from a recently published study by a Harvard researcher showing that use of any illicit drug, but especially marijuana, significantly increases the probability that an individual will abuse other drugs during the course of a lifetime" (my emphasis). Could it be true? Had the notorious gateway or "stepping stone" hypothesis about marijuana actually received some empirical support?

Since you didn’t specify the exact study in your letter, I was left wondering what I’d missed, since evidence supporting the gateway hypothesis, from Harvard, no less, would ordinarily have ignited an all-out media blitz from NIDA. After all, your group never misses a chance to capitalize on bad news about pot. But I hadn’t heard a word about such research, and I usually keep pretty close tabs on this stuff. So what was up?

After some fruitless attempts to find out from your office what Harvard study you had in mind, I visited NIDA’s web site and found a press release on a recent, NIDA-funded study led by Dr. Ming Tsuang of Harvard. It had appeared in the November, 1998 issue of the Archives of General Psychiatry, and was titled "Co-occurrence of Abuse of Different Drugs in Men." This had to be it, right?

Well, sort of. Going to the Archives web site, I discovered that Tsuang et al. had conducted a large twin study of Vietnam vets showing that individuals who abuse one type of illicit drug are indeed predisposed to abuse other drugs, for reasons having to do with a person’s genetics and environment. As they put it in their summary of findings, "Abusing any category of drugs was associated with a marked increase in the probability of abusing every other category of drugs."

But what about marijuana? Did this recent Harvard study show that using it especially leads to the abuse of other drugs? Not at all, in fact quite the opposite.

First, Tsuang defines quite specifically what he calls the "marijuana gateway model": "…the shared genetic and environmental influences operate through their influence on marijuana abuse, which in turn influences the abuse of every other category of drug. The gateway model of drug abuse…presents a sequential theory of lifetime patterns of drug initiation in which cigarettes, alcohol, or marijuana represent phases in drug use that facilitate involvement with "harder" drugs."

Second, he tests the gateway model against the twin study data, seeing to what extent it matches the actual patterns of co-occurrence. It doesn’t. Tsuang explicitly rejects the marijuana gateway model in favor of a model in which genetic and environmental influences on drug abuse don’t operate via marijuana. Visit the site, read for yourself.

It’s hard to imagine a more blatant conflict between your supposedly Harvard-backed claim that pot in particular leads to other drugs and Tsuang’s finding, a finding, by the way, which NIDA has been careful never to mention, even though it funded the research. This means either that there’s yet another recent Harvard study on co-occurring drug abuse that contradicts Tsuang’s (highly unlikely, since the world would have heard about it) or that in making this claim, you badly compromised NIDA’s vaunted commitment to scientific integrity, by inverting the findings of your own research.

Given NIDA’s penchant for intimidation and its selective reporting of data on marijuana, the second possibility, unfortunately, seems most probable. What agency, after all, put pressure on the World Health Organization to drop from its 1998 report on international drug trends a section comparing cannabis favorably to alcohol and tobacco? What other agency would stoop to trumpet, as evidence of pot’s addictiveness, studies (reported in Science) in which rats were injected with massive doses of THC and then chemically withdrawn using potent antagonists, as if this had the least relevance to how people use cannabis? NIDA’s official stance on cannabis seems increasingly disingenuous considering the recent Institute of Medicine’s report on medical marijuana, which concluded that pot is neither a gateway drug nor particularly addicting.

So why, pray tell, would you so mislead the readers of the Globe? If unintentional, it shows a stunning carelessness with the facts; if intentional, an equally stunning disregard for science and the public trust. Either way, it looks bad, very bad. My wild guess (you might call it the "gatekeeper" hypothesis) is that your agency, which conducts 85% of the world’s research on drug abuse, is also heavily invested in defending our failed 60 year policy of marijuana prohibition, and so must carefully control access to and interpretation of evidence on the health effects of cannabis.

Sounds crazy, but maybe you need to divest yourself of policy commitments to honor your commitment to science. Just a thought. But remember, with published research only a mouse-click away, it’s getting harder and harder to pull a fast one.

Yours,

Thomas W. Clark, Boston