Straight Dope

The Research on Marijuana Safety

(Part 1 of 4) by Gary Stimeling

 

Copyright 2005 Psychotropics Cornucopia, Inc. All Rights Reserved.

 

I wish to propose for the reader’s favourable consideration a doctrine which may, I fear, appear wildly paradoxical and subversive. The doctrine in question is this: that it is undesirable to believe a proposition when there is no ground whatever for supposing it true. I must, of course, admit that if such an opinion became common it would completely transform our social life and our political system….

— Bertrand Russell, “On the Value of Scepticism,” Sceptical Essays I (1928)

 

            Of all the thousands of medicinal and psychoactive drugs known to earthlings, cannabis is by far the most extensively studied. Science has answered most of the questions put to it about marijuana. Indeed, science has answered these questions over and over again, generation after generation, always coming to more or less the same conclusions: The drug is very enjoyable, often beneficial, medically useful, and remarkably harmless even when overused, posing little or no threat to public health and safety. The accumulated body of research is vast and constantly growing, yet little of this knowledge has made it into the mainstream media or the thinking of lawmakers, and it has had no effect on American federal policy since prohibition began in 1937. In fact, the government has consistently made its programs and pogroms more at odds with science rather than less. In their propaganda campaigns, the White House Office of National Drug Control Policy (ONDCP) and its allies continue to fight the facts of research with untruths disproved long ago in the scientific literature—avowedly and with the consent of Congress.([1]) This cognitive dissonance may seem surprising until one examines Dope War politics [see the Activism page]. As George Carlin has observed, “The reason the mainstream is referred to as a stream is because of its shallowness.”

Opponents of freedom for cannabis users often claim a scientific consensus based on the following lie, which seems to have been told first in a pamphlet from the California Narcotic Officers’ Association: “There are over ten thousand documented studies available that confirm the harmful physical and psychological effects of smoking marijuana.”([2]) Actually, scientists have published some five thousand treatises on cannabis since 1839, and the overwhelming majority of those that deal with possible harm indicate that the risks are small or nonexistent.

 

Alleged Short-Term Physical Dangers

            Suppressionists often cite marijuana-related hospital emergency room visits as evidence of the drug’s dangers. Emergency room staff now must test for illegal drugs in patients they admit. They’ve long been required to ask about recently used drugs, legal or illegal, and list up to five of them on the medical chart. If the patient mentions or tests positive for illegal ones, the visit is automatically tagged as drug-related, whether or not the drugs have caused the problem, and the event must be reported to the federal Drug Abuse Warning Network (DAWN). Despite the large number of irrelevant listings generated by this system, cannabis is the only illicit drug whose percentage of ER mentions is less than the percentage of the general population who use it, according to federal statistics.([3])

In a typical year, about 1.5 percent of patients making “drug-related” ER visits report using only marijuana. An unknown but small proportion of those are actually prompted by an effect of marijuana, usually a panic attack caused by a large dose, a reaction that may include the fear that one is dying. This is very unpleasant but not the least bit dangerous.

In all of medical history, there is no record of death from an overdose of cannabis.([4]) Even extrapolating from the most alarmist toxicity data in rats, produced by Gabriel Nahas, a scientist who has devoted his life to proving that cannabis is deadly,([5]) a 175-pound person would have to ingest about 10 grams of pure THC at one time to have a 50/50 chance of dying. To smoke this amount, spread over the course of a 17-hour day, would require power-sucking 1,000 average-sized joints of low-quality weed containing 2 percent THC (one per minute) or 100 joints of the world’s strongest 20-percent ganja (one every 10 minutes).([6])

Work by a different scientific team indicates that the average lethal dose in rats is actually 6 to 15 times larger. These researchers failed to induce any deaths at all in dogs using bodyweight-adjusted doses up to 24 times the level used in Nahas’s tests. In monkeys, more relevant to humans, they got no deaths at 72 times that level.([7]) This suggests that even 7,200 joints of hash or super weed smoked, or 16 pounds eaten, would not be fatal from the THC, although it certainly would be from lung failure or stomach rupture. All in all, Oxford pharmacologist Leslie Iversen rates cannabis much less toxic than aspirin, from which hundreds die each year of gastrointestinal bleeding.([8])

            Cannabis increases the pulse rate 20–50 percent while dilating the blood vessels, so the heart pumps more blood with the same or less effort. Breathing becomes slower and deeper. The combination increases oxygenation throughout the body.([9]) The effect is similar to that of mild to moderate exercise, but it diminishes with regular use. The vasodilation causes red eye, which also is harmless, except that it increases the risk of being caught.

Anxiety is most common at high doses, especially when neophytes sample strong material loaded with THC. Enhanced perception of the body may focus attention on the more rapid heartbeat, leading to “the fear.” In addition, cannabis sometimes releases memories of an unpleasant event from the past, or clarifies an emotional conflict in the present, which can cause anxiety but also may be an opportunity to work through the problem. Also, users sometimes experience depersonalization, a sense of separation from the self, of being a detached observer (a true scientist!). This may lead to panic, or it may be felt as a pleasant vacation from the ego, an introduction to the nonattachment cultivated by Eastern religions and ancient philosophies.

An important study of 2,500 people who’d smoked cannabis at least five times found that 40 percent felt muddle-headed and less able to solve problems while high, even though most of them still enjoyed the euphoria and relaxation. This sample was large enough to allow researchers to compare pairs of identical vs. fraternal twins for this confusion, as well as for anxiety reactions. Apparently these responses are caused by genetic differences.([10]) THC is the chief pharmacologic contributor to panic attacks, and that they are less likely with Cannabis indica, in which THC is balanced by large amounts of cannabidiol, a hypnotic sedative.([11])

            Cannabidiol tested on 15 insomniacs improved their sleep dramatically,([12]) and as the high wears off, most people find that marijuana promotes sound sleep, perhaps spiced by a vivid dream. But some find the opposite, particularly at high doses of cannabidiol-poor sativa strains. Anxiety and undesired wakefulness are best treated by reassurance from a friend or lover, hand-holding, massages, and hugs. A sedative herbal tea like valerian will help. In extreme cases, which occur more often after eating cannabis than smoking it, a tranquilizer may be needed.

            Some people report a hangover of slight fatigue and mental fogginess the day after, but two studies have agreed with the majority opinion, finding instead an improved mood and clearheaded alertness the next morning.([13]) Pure THC, on the other hand, often produces mild but demonstrable confusion the next day, especially at high doses,([14]) suggesting that cannabidiol or other cannabinoids protect against this effect, too.

 

Now! Stronger Than Ever!

            One of the myths prohibitionists flog is that more potent strains of cannabis make it a dangerous drug now, even if Sixties Mexican wasn’t. But scare stories about new, super-strong pot began at Senate hearings back in 1974.([15]) They have often been repeated in uncritical media whose editors have no real-world understanding of the drug or its users.([16]) Criers of the potency bogeyman often make absurd claims that marijuana is 20, 50, or 100 times stronger than it used to be. Such statements are wrong on two counts.

            In the first place, the THC content of each variety of cannabis is genetically determined and probably has remained fairly constant since prehistoric times. The government’s own statistics show that it hasn’t changed much in three decades.

Since 1972, the University of Mississippi Research Institute of Pharmaceutical Sciences Potency Monitoring Project (PMP) has tested samples of marijuana seized by police. Most warnings about increased potency rest on comparisons of PMP figures after 1980 with those before. In the 1970s, when few samples were tested, the average recorded THC content was under 1 percent; one year it was 0.18 percent.

These numbers were due to incompetent storage and testing.([17]) If they had been accurate, the whole phenomenon of getting high would have had to have been a mass delusion. Marijuana with less than 0.5 percent THC has no mental effect whatsoever when smoked, and unless potency is above 1 percent, most people can’t tell the difference between pot and a placebo from which all THC has been removed with acetone.([18]) PharmChem, an independent street-drug testing service active in the 1970s, consistently recorded average THC levels between 2 and 5 percent.([19]) Around 1980, PMP scientists improved their procedures and began receiving more samples. Since then their yearly averages have held steady between 2.0 and 4.5 percent.([20])

Nearly all of the PMP samples have been commercial grade mass-market pot rather than high-end connoisseur types, which, being sold in small quantities over small networks, are less vulnerable to law enforcement. Plant breeders have created some very strong varieties in recent years, but there is a genetic limit to THC content—10 to 20 percent in cured buds of the best varieties. Rather than increased potency, the chief aims of selective breeding have been to increase weight yield per plant, to produce short plants that mature fast for safer clandestine growing, and to enhance various medical properties. Service in Vietnam gave thousands of soldiers a chance to try the good stuff, and most people who got stoned in the Sixties and Seventies know that extremely powerful grass from Thailand, Panama, Hawaii, and elsewhere could sometimes be found. In 1968, I myself was privileged to sample some astonishing black cannabis brought from Alexandria, Egypt, by a merchant seaman.

High-test weed may be more widely available now than in decades past, though I’ve found no scientific surveys to prove this. If so, we have the narcopolice to thank, for forcing much of the American market to switch from outdoor-grown imports to intensively nurtured indoor domestic.

That brings us to the second and more important reason the potency scare is bunk: Cannabis rich in THC is actually safer than weaker material. The quick effect of smoking lets people titrate the dose, ingesting roughly the same amount of THC regardless of its concentration in the plant.([21]) Thus, the stronger the herb, the less a user smokes to get high, thereby inhaling less of the harmful compounds formed when any vegetation burns.([22])

Long-term users who don’t smoke constantly tend to get higher from the same amount and quality anyway, due to the phenomenon of reverse tolerance. Tolerance—diminution of effect with continued use—develops to some of marijuana’s effects, such as the pulse-rate increase, and even to the high if you smoke pipe after pipe day after day. However, unlike heroin and cocaine users, many marijuana users find that, as time goes on, they need less rather than more to reach their preferred level of euphoria. Experienced users become more efficient smokers,([23]) and reverse tolerance continues to develop long after they’ve learned the technique. With aging, the brain becomes more sensitive to drugs anyway,([24]) so pot of any given strength may seem more powerful than it was in one’s youth. Moreover, because a fatal OD is impossible, and because THC causes no known damage to human tissues or organs, a greater concentration of it does not mean greater danger, as it does with many other substances. In fact, the forced increase in homegrown primo may be the only case in which drug laws have actually (though unintentionally) decreased a hazard from a drug.

 

Gateway to Mainline

            The addiction myth is another Dope War vampire that keeps coming back from the dead, no matter how many stakes science drives into its heart. It’s a two-parter, with variations:

1.     Marijuana is insidiously addictive even though it displays few characteristics of other addictive drugs, and none to the same degree. Or maybe it’s not really addictive, but at least it’s so doggone pleasant that anyone who tries it even once will be drawn to use it constantly. But then,

2.     The first blush wears off. Or maybe marijuana somehow changes the brain into an indiscriminate drug sponge. In any case, the infatuation with cannabis wanes, and, like a bored lover, the user seeks other substances with stronger “kicks” (the Puritan word for “pleasures”). But these other drugs too are so much more rewarding than daily life in the modern world that the poor soul ends up being drawn helplessly from that first puff of weed down into a quicksand of addiction and degradation.

The words “addiction” and “dependence” are often used interchangeably. Strictly speaking, addiction refers to a drug habit enforced by physical withdrawal symptoms that produce severe sickness or even death when one tries to quit. Because most pharmaceutical antidepressants can produce suicidal depression when stopped abruptly, they are addictive in this sense. Heroin, barbiturates, and alcohol cause addiction if used continually for long enough.

Dependence is a fuzzier term whose meaning varies with context and the person using it. One’s relationship with a plant spirit (the aboriginal term for a drug) can take many forms, all of which are called dependence by those who disapprove. It may mean a craving that the user regrets but feels helpless to control, like unrequited love. It may give pleasure followed by guilt, like cheating on a spouse. It can devolve into meaningless ritual that yields only self-hatred, like a bad marriage. Or it can simply mean occasional or continued use driven only by the user’s pleasure in it despite external condemnation—a rewarding fling or long-term affair.

Withdrawal symptoms may or may not be present in dependence. If present, they may be distressing but not dangerous, or the condition should properly be called addiction. A drug of dependence can be harder to kick than an addictive one, despite the lack of life-threatening withdrawal symptoms. A tobacco habit is usually harder to break than a heroin habit. Cocaine and speed produce dependence in some people, marijuana in a few, tobacco in nearly all. Dependence began to be emphasized in 1964 when a committee of United Nations doctors realized that it covered a wider range of problems than addiction—and coincidentally would generate many times more patients.([25])

Marijuana breeds a very unusual monkey. When pharmacologists list drugs according to addiction or dependence potential, cannabis is always near the bottom of the list, below nicotine, heroin, morphine, barbiturates, alcohol, opium, Valium, cocaine, amphetamines, and caffeine.([26]) It certainly ranks below most mind-altering pharmaceuticals and probably below the most overlooked of all popular drugs—chocolate.

A federal survey in 1994 found that 31 percent of Americans over the age of twelve had tried marijuana, but only 0.8 percent smoked it every day or two even when they could—2.5 percent of those who’d tried it.([27]) Those figures have not changed much in subsequent surveys. Unlike people dependent on other habit-forming drugs, most daily marijuana users who decide to quit are able to do so without much trouble, and the vast majority of them can smoke pot occasionally without reverting to constant use.([28])

A minority of heavy pot smokers do find it hard to quit or cut back when they want to,([29]) and since about 1990 there has been a large increase in the number of marijuana users in drug-treatment programs. However, most of the increase is due to coercion.

Prohibition makes maintaining a supply of cannabis much more time-consuming and dangerous than picking up a pound of coffee at the corner deli. Most people in the illegal-drug treatment business say a willingness to deal with the hassle in order to obtain one’s preferred stimulant is proof of dependence rather than independence. The fourth edition (1994) of the American Psychiatric Association’s Diagnostic and Statistical Manual even lists arrest as evidence that a person has an abuse problem with the drug itself! Naturally, some users sign up for a program to try to get rid of their desire and get out from under the law’s thumb.

In addition, drug-testing programs catch marijuana users more often than users of other drugs, because cannabis metabolites stay in the body longer. Users then are forced into treatment to satisfy their parents or spouses, keep their jobs, or stay out of jail, regardless of whether they’ve ever had any problems with pot. Nearly all of those who voluntarily seek treatment for marijuana abuse report it as secondary to abuse of other drugs.([30])

Efforts to demonstrate THC addiction in the laboratory have fared poorly. Unlike the case of cocaine, opiates, alcohol, barbiturates, and other habit-formers, no matter how much THC you give the lab rats, after you stop, they do not press levers to get more of it.([31]) One group of researchers did succeed in producing physical withdrawal symptoms in mice, but only by injecting them with huge doses of THC for four days and then giving them an antagonist drug to immediately remove all cannabinoids, internal as well as external, from their receptors.([32]) This is in stark contrast to actual human use, which involves much lower levels of THC and gradual replacement of it at receptor sites by normal levels of endocannabinoids as the high wears off.

Studies on people have been even less encouraging for the treatment industry. In a 1967 experiment, ten men in the Federal Narcotics Hospital in Lexington, Kentucky, were required to inhale a joint every waking hour for a month, but doctors still found no withdrawal symptoms upon abruptly ending the smokathon.([33]) When another group of researchers fed volunteers enormous daily doses of pure THC for a month, then stopped, the subjects experienced nothing more serious than mild nervousness, sweating, and nighttime wakefulness, the same symptoms reported by about one-sixth of heavy users in the real world when they suddenly quit.([34])

Drug treatment is an example of medicalization, the encroachment by doctors, in this case as agents of the state, into areas of life that were formerly matters of personal effort and help from friends. In an Australian study of long-term heavy cannabis smokers, evaluators judged 57 percent as dependent, though only 9 percent had ever felt their use sufficiently out of control to seek help.([35]) Most of the popular and scientific articles claiming to have verified marijuana addiction in humans are written by treatment providers.([36]) In fact, in a transparent effort to drum up business, some of them perversely argue that all cannabis use should be considered addiction, even when a person’s symptoms don’t satisfy their own professional guidelines for dependence—precisely because marijuana addiction is “subtle and difficult to identify.”([37]) Tremendous effort has gone toward teasing out evanescent evidence of cannabis dependence and/or addiction, and ratifying it for broad application in drug-screened populations.([38]) To understand where this trend could lead, consider: In the Third Reich, all use of drugs not approved by the state was officially diagnosed as mental illness, and the mentally ill were systematically murdered in the gas vans. Will the final solution to cannabis use be kinder and gentler, perhaps a compulsory vaccine against the effects of THC?

While “marijuana addiction” is a misrepresentation of the facts, the gateway or stepping-stone theory is a logical fallacy akin to the domino theory of communism or the porn theory of sex-killers. Cold War ideologues of the West blamed all pro-socialist elections and revolutions on subversion from communist states, ignoring the attraction that the poor might feel for any alternative to their impoverishment by corporate oligarchs. By the same token, sexual images supposedly explain Ted Bundy, but not the 50 million American men (and women and couples) who merely get excited by them without wanting to kill anyone. Drug-suppression ideologues, too, blame the totality of a phenomenon—use of drugs they condemn, some of which undeniably cause harm to some users—on its largest and most benign subset, marijuana use.

In part, the gateway theory is a misunderstanding of statistics, a confusion of cause and effect conditioned by propaganda.([39]) Most marijuana fans started out with booze, cigarettes, coffee, chocolate, Ritalin, Valium, Adderal, Paxil, or Zoloft, but few people blame pot smoking on these legal and prescribed mind-alterants. Most users of less common illegal drugs like heroin and cocaine have tried marijuana first, simply because it’s more available—but as many as 39 percent have not, depending on locale and social class.([40]) The U.S. government’s own statistics show that only 1 in 200 Americans who try marijuana go on to smoke crack even once a month. Only 1 of 333 pot initiates use heroin monthly.([41]) You might as well say that walking leads to bungee-jumping.

Lab rats given THC don’t press levers to get other drugs.([42]) Surveys of drug use throughout the world have shown that the specific hard drugs to which the gateway drug leads vary by age, nationality, social class, education, and fashion. In the United States in the 1950s, marijuana supposedly led to heroin; in the 1960s, LSD; in the 1970s, Quaaludes and PCP; in the 1980s, cocaine; in the 1990s, Ecstasy. Rates of use of other drugs show no correlation with marijuana use over time, either. Of course, the fact that the law lumps all banned substances together does tend to erase the boundaries between them in the criminalized underground. And once people realize they’ve been lied to about grass, they naturally assume, not always correctly, that authoritarian sources are lying about other drugs, too. Propaganda buries the facts about actual dangers, so in that sense the law itself is the only real gateway.

Despite all this, the gateway idea does contain a grain of truth. It simplistically explains why mind-altering drugs are so attractive to so many people, without forcing anyone to wonder why contemporary life creates demand. Most grown-ups in “leisure societies” spend two or three times more hours working than so-called primitive peoples did, enduring far higher levels of continuous tension.([43]) To prepare for these joys of adulthood, children spend 12 to 20 years walled up in schools developing myopia. People in the sweatshop colonies have it far worse. Can we devise a better situation for making people crave a change of consciousness? Anyone who has ever unwound with a martini or a joint after a hard day knows one reason we like drugs.

While some illegal drug use is reactive against society’s discontents, another part is proactive fulfillment of a normal human desire for illumination, an unknowing (or knowing) attempt to re-create bygone initiations, vision quests, shamanic experiences, and plain old euphorias, all of which were aided by a wide variety of natural drugs in natural societies.([44]) Power seeks to eliminate or marginalize transcendence in order to promote the orderly service of elites by wage-slaves. Expanded consciousness is the antidote for its contraction—the soul-death demanded by National Capitalism([45]) and promoted by its approved soporifics, energizers, and adjustment drugs. The idea is to maximize need while minimizing supply, partly to profiteer in secret and partly to keep the machine humming. Partaking of the kind herb is called “getting high” because it raises us briefly above the whole demonic system. One taste of this exalted perspective inevitably makes us desire another, even without any physical addiction.

Gabriel Nahas, one of the most ardent foes of pharmacological freedom, has recognized this point unconsciously: “The biochemical changes induced by marijuana…lead the user to experiment with other pleasurable substances.”([46]) Science indicates that the change is not biochemical, however. All addictive drugs raise or lower levels of the neurotransmitter dopamine in the brain’s pleasure center, and the “drug sponge” idea rests on an experiment that seemed to indicate that cannabis raises dopamine levels in this area of the brain.([47]) Gateway theorists love to cite it as the proof they’ve been seeking for so long.([48]) Other work found no such correlation,([49]) however, and research on the internal cannabinoid system suggests that it is a master controller that moderates or normalizes levels of other neurotransmitters throughout the nervous system.([50]) This may be the reason that many people have used marijuana successfully to help them beat real addictions.([51])