The war on drugs is really a war on Marijuana,” says Professor Lynn Zimmer, a sociologist at Queens College, in New York, who is widely regarded as one of the nation’s leading analysts of drug policy. Marijuana, says Zimmer, is the leading justification for drug testing in the workplace, the main target of anti-drug efforts in the schools and the media, and the principal preoccupation of drug warriors in and out of government today. The drug warriors’ tactics include – along with arrests, seizures, incarceration and the intimidation of doctors who would prescribe pot for the terminally ill – a more sinister approach. Spokesmen are quoted by journalists and appear on the evening news and on talk shows, making frightening claims about marijuana’s harmful effects, spinning unproven theories and, in some cases, distorting the known truth in an effort to demonize even casual users of pot.
It’s no wonder that the warriors find themselves in a quandary. They’re essentially fighting a war against the 70 million Americans who have tried marijuana, including half of all Americans aged 18-35 and more than a quarter of everyone older than 35. Polls have indicated that a fourth of all adult Americans favor legalizing pot, which, after alcohol, tobacco and caffeine, is the fourth most popular psychoactive drug in the world.
“You can’t scare middle-class parents with a war on heroin and cocaine,” says Zimmer. “These drugs are too removed, too remote. Marijuana brings it home.”
Bill Clinton’s administration, desperate not to appear soft on drugs, has indulged in its share of scare tactics. Clinton’s newly appointed drug czar, Gen. Barry McCaffrey, has set the tone for the federal government’s new stance, threatening sanctions against medical doctors in California and Arizona (RS 750/751), where citizens voted in November to allow the medicinal use of cannabis. More typical, however, is the approach taken by Secretary of Health and Human Services Donna Shalala, who disingenuously told reporters last December, “All available research has concluded that marijuana is dangerous to our health.”
Is pot dangerous? Is there any scientific research to back up Shalala’s claim? There are, of course, reasons to be concerned about marijuana. It is, like alcohol, a powerful psychoactive drug. Used irresponsibly, it contributes to accidents on the roads and in the workplace. During the period of intoxication, short-term memory is impaired. Heavy pot smokers face some of the same risks as cigarette smokers. And some people become dependent upon marijuana, using it as a crutch to avoid dealing with relationships and responsibilities.
Among kids, especially, it is the daily use of marijuana, not experimental or occasional use, that merits concern. According to the latest annual survey of drug use among high-school students, the percentage of eighth-graders who admit to daily pot smoking increased from 0.2 percent in 1991 to 1.5 percent in 1996. Among 10th-graders, there was an increase from 0.8 percent to 3.5 percent; among seniors, an increase from 2 percent to nearly 5 percent. Of course, smoking marijuana every day would contribute to a teenager’s problems in school and socially, but more likely it is an indicator of something else that is basically wrong.
On the other hand, there is ample evidence that the majority of the 70 million Americans who have tried marijuana are doing just fine. Since the early 1970s, the government has funded studies that have ended up proving that pot is not harmful, then disavowed the findings. In 1988, following an extensive review of the scientific evidence on marijuana, the Drug Enforcement Administration’s own administrative-law judge, Francis Young, concluded that marijuana “in its natural form is one of the safest therapeutically active substances known to man.” Virtually every independent commission assigned to examine the evidence on marijuana and marijuana policy – including the Shafer Commission appointed by President Richard Nixon, a National Academy of Sciences committee in the early 1980s, and numerous others both in the U.S. and abroad – have concluded that marijuana poses fewer dangers to individuals and society than either alcohol or tobacco and should be decriminalized.
And there is little reason to expect anything different from the Clinton administration’s January announcement that it will spend $1 million to review all the evidence on the medical benefits of marijuana. The problem is that no Congress or president has ever had the guts to follow through on the recommendations of independent commissions assigned to balance the risks and harms of marijuana with the risks and harms of marijuana policies. It’s still impossible, for instance, for any government official to speak out publicly about the difference between responsible and irresponsible use of marijuana, as they would with alcohol. All marijuana use is defined as drug abuse – notwithstanding extensive evidence that most marijuana users suffer little if any harm. That position may be intellectually and scientifically indefensible, but those in government regard it as politically and legally obligatory.
So the government resorts to scare tactics and misinformation, relying increasingly on three claims: that today’s marijuana is much more potent than the version that kids’ parents smoked a decade or two ago; that new research has shown the drug to be more dangerous to our health than previously thought; and that marijuana use is a gateway to more dangerous drugs.
Are these claims true? Is today’s marijuana much more potent? Is marijuana much more dangerous than previously believed? Is marijuana a “gateway drug”? Most marijuana researchers depend on government grants to finance their studies. This poses two problems. First, the government tends to encourage and fund only those research proposals that seek to identify harmful effects of marijuana. There are few incentives to investigate the benefits of marijuana, medicinal or otherwise, and little interest in determining either the safety margins of occasional use or ways of reducing the harms of marijuana use. Studies that identify marijuana as harmful are well publicized by the governments’ public-affairs officers. Findings that fail to confirm any harms are ignored.
Second, few marijuana researchers dare publicly challenge the government’s anti-marijuana campaign. Scientists know that the grant-review process can be both scientifically objective and politically subjective. If too many studies fail to identify and emphasize the harms of marijuana, subsequent research proposals may not fare well in grant competitions. It takes a lot of courage for a scientist — dependent upon government grants for his or her livelihood – to raise questions about government policies and statements regarding marijuana. Not many scientists are that brave.
Fortunately, there are a few researchers who maintain their independence. Zimmer, the sociologist at Queens College, and Dr. John P. Morgan, a physician and pharmacologist who teaches at the City University Medical School, in New York, don’t rely on government funding. They have recently completed a book, Marijuana Myths, Marijuana Facts: A Review of the Scientific Evidence, that systematically analyzes and dissects hundreds of studies on marijuana, including virtually all of those cited by government officials and other anti-drug crusaders to justify the war on marijuana. The result is the most comprehensive and objective review of the scientific evidence on marijuana since the National Institute of Medicine’s report in 1982 – one that both debunks many of the myths propagated by drug warriors and tells the truth about what is actually known of marijuana’s harms and margins of safety. What follows is drawn largely from their work.
The Potency Question
No claim has taken hold so well as the charge that marijuana is much more potent than in the past. “If people . . . confessing to marijuana use in the late ’60s . . . sucked in on one of today’s marijuana cigarettes, they’d fall down backward,” said William Bennett, President George Bush’s first drug czar, in 1990. “Marijuana is 40 times more potent today . . . than 10, 15, 20 years ago,” another drug czar, Lee Brown, claimed, in 1995. And from the ranking Democrat of the Senate Judiciary Committee, Joseph Biden, in 1996: “It’s like comparing buckshot in a shotgun shell to a laser-guided missile.”
Is any of this true? No. Although high-potency marijuana may be more available today than previously, the pharmacological experience of smoking marijuana today is the same as in the 1960s and 1970s. The only data on marijuana potency over time comes from the government-funded Potency Monitoring Project at the University of Mississippi. Since 1981, the average THC (tetrahydrocannabinol, marijuana’s principal psychoactive chemical) content of PMP samples – all of which come from drug seizures by U.S. police agencies – has fluctuated between 2.28 percent and 3.82 percent. The project’s findings during the 1970s were substantially lower, possibly because the samples were improperly stored (which can cause degradation of THC) and partly due to an overdependence on low-grade Mexican “kilobricks.” Independent analyses of marijuana during the 1970s, which included samples from sources other than police agencies, reported much higher THC levels, ranging from 2 percent to 5 percent, with some samples as high as 14 percent.
Marijuana of less than 0.5 percent potency has almost no psychoactivity; in fact, in laboratory studies, subjects are often unable to distinguish a placebo from marijuana with less than 1 percent THC. It’s not very likely that marijuana would have become so popular during the 1970s if the average THC content had been so low. Today, some regular marijuana users may have access to expensive, high-potency marijuana, often grown indoors under artificial light by small-scale, low-volume growers. But the potency of the “commercial grade” marijuana smoked by most Americans is not much different than it was 10, 15 or 20 years ago.
Even if marijuana potency had increased, that would not mean the drug has necessarily become more dangerous. It is impossible to consume a lethal dose of marijuana, regardless of its THC content. And in laboratory studies, smokers often fail to distinguish variations in potency of up to 100 percent. Increases of 200 percent to 300 percent in potency result in only 35 percent to 40 percent increases in smokers’ “subjective high” ratings. “Bad trips” and other adverse psychoactive reactions typically have little to do with marijuana potency. Moreover, when potency increases, smokers tend to smoke less, thus causing less damage to their lungs.
The bottom line is this: If parents want to know what their kids are smoking today, they need only recall their own experiences. Neither marijuana nor the experience of smoking marijuana has changed much.
Sex, Health and Memory
Claims of increased THC Potency aside, much of the new war on marijuana relies on claims of new scientific research that shows marijuana to be far more dangerous than previously thought.
There are tons of anecdotal reports that marijuana enhances sex. And there are repeated claims that marijuana interferes with male and female sex hormones, can cause infertility, and produces feminine characteristics in males and masculine characteristics in females. Speaking at Framingham High School, in Massachusetts, in late 1994, President Clinton spoke about “the danger of using marijuana, especially to young women, and what might happen to their child-bearing capacity in the future.”
What’s the truth? Some animal studies indicate that high doses of THC diminish the production of some sex hormones and may impair reproduction. In human studies, however, scientists typically find no impact on sex-hormone levels. In the few studies that do show some impact, such as lower sperm counts and sperm motility, the effects are modest, temporary and of no apparent consequence for reproductive capacity. A real-life example: Jamaica’s Rastafarians, who smoke large amounts of the sacred herb, appear to have no problem making babies.
In 1972, a letter to the New England Journal of Medicine described three cases of breast enlargement in men who had smoked marijuana. In 1980, a letter to the Journal of Pediatrics described a 16-year-old marijuana smoker who had failed to progress to puberty. Both reports received substantial publicity, but neither has been confirmed through research. But studies involving larger numbers of marijuana users and non-users have found no evidence that marijuana distorts or delays sexual development, masculinizes females or feminizes males. There may be good reasons for telling kids not to smoke marijuana, but the president’s warnings were based on myth, not fact.
Now that thousands of people with AIDS are smoking marijuana to stimulate their appetites and promote weight gain, opponents keep insisting that marijuana’s damaging effects on the immune system negate any potential benefits. Here again, the claims are based almost entirely on studies in which laboratory animals are given extremely large doses of THC. There’s no evidence that marijuana users have higher rates of infectious disease than non-users. That’s not to say that there are no dangers. For people with compromised immune systems, smoking can cause lung infections. There is also a risk for AIDS patients that they will contract a pulmonary disease called aspergillosis caused by fungal spores sometimes found on improperly stored marijuana. One solution to this problem would be careful screening of marijuana supplies, a role for the government or pharmaceutical companies. And that is another reason to prescribe legal, controlled marijuana to more than the eight Americans who are now entitled to receive it.
Everyone knows that marijuana – like other psychoactive drugs consumed in sufficient doses – screws up short-term memory. Kids who get high (or drunk) before going to class are less likely to learn what their teachers are trying to teach them. Their minds are more likely to wander. People under the influence of marijuana can remember things they learned previously, but their capacity to learn and recall new information is diminished. Although some find marijuana useful for problem solving and creative tasks, there is little question that marijuana is not conducive to learning in school and other highly structured environments.
The question of whether marijuana use permanently impairs memory and other cognitive functions is a separate issue. During the ’70s, the U.S. government funded three comprehensive field studies in Jamaica, Greece and Costa Rica, in which long-term heavy cannabis users and non-users were subjected to a battery of standardized tests of their cognitive functions. The researchers found virtually no differences between the two groups.
More recently, two studies funded by the National Institute on Drug Abuse reported evidence of cognitive harm in high-dose marijuana users. The first, published in Psychopharmacology, in 1993, found that heavy marijuana users – who reported seven or more uses per week for an average of 6.5 years – scored lower than non-users on math and verbal tests. But the researchers also found that “intermediate” users – those smoking marijuana five to six times per week – were indistinguishable from non-users.
The second study, published in the Journal of the American Medical Association, in 1996, found differences between daily marijuana users and those who smoked fewer than 10 times per month, but the differences were minor. The light smokers performed slightly better on two memory tests and one card-sorting test – while no differences were found on tests of attention, verbal fluency and complex drawing. What we know now, based on existing research, is that if heavy marijuana use produces cognitive impairment, it is relatively minor – and may have little or no practical significance.
The “Gateway Theory,” formerly known as the “steppingstone hypothesis,” has long been a staple of anti-marijuana campaigns. Marijuana use, it is claimed, leads inexorably to the use of more dangerous drugs like cocaine, heroin and LSD. If we can stop kids from trying marijuana, we can win the drug war.
The most recent, and oft-repeated, version of the gateway theory – an analysis conducted by the National Center on Addiction and Substance Abuse at Columbia University – asserts that youthful marijuana users are 85 times more likely than non-users to use cocaine. To obtain this figure, the proportion of marijuana users who had ever tried cocaine (17 percent) was divided by the proportion of cocaine users who had never used marijuana (0.2 percent). The “risk factor” is large not because so many marijuana users experiment with cocaine – only a minority actually do – but because people who use cocaine, a relatively unpopular drug, are likely to have also used the more popular drug marijuana. Similarly, marijuana users are more likely than non-users to have had previous experience with legal drugs like alcohol, tobacco and caffeine.
Alcohol, tobacco and caffeine do not cause people to use marijuana. And marijuana does not cause people to use cocaine, heroin or LSD. There is no pharmacological basis for the gateway theory, since marijuana does not change brain chemistry in a way that causes drug-seeking, drug-taking behavior. In fact, there is no theory here at all – just a description of the typical sequence in which people who use many drugs begin by using ones that are more common.
The relationship between marijuana use and the use of other drugs is constantly changing. In some societies, marijuana use follows, rather than precedes, use of heroin and other drugs. Among American high-school seniors, the proportion of marijuana users who have tried cocaine decreased from a high of 33 percent, in 1986, to 14 percent, in 1995. Americans who smoke pot may be more likely to try other illegal drugs than those who don’t smoke it. But for a large majority of marijuana users, marijuana is a terminus rather than a gateway drug. “Now we’re putting the research into the hands of parents,” Donna Shalala claimed at a recent press conference, renewing the government’s war against marijuana. But if it’s the truth that Shalala wants to distribute, Zimmer and Morgan’s Marijuana Myths, Marijuana Facts is a better source.