1. Marijuana is more harmful than tobacco – Many people think smoking marijuana is just as harmful as smoking tobacco, but this is not true for many reasons. (For example, most marijuana smokers smoke the bud, not the leaf, of the plant. The bud contains only 33% as much tar as tobacco; Not one case of lung cancer has ever been successfully linked to marijuana use; Cannabis, unlike tobacco, does not cause any narrowing of the small air passageways in the lungs.) Click here for more details.
2. Marijuana is a gateway drug – We were taught in school that people who try marijuana eventually move on to crave harder drugs, usually with the implication that marijuana is addictive and coke or crack are just the next step. In hindsight, this is absurd. The primary basis for this "gateway hypothesis" is a recent report by the Center on Addiction and Substance Abuse (CASA), claiming that marijuana users are 85 times more likely than non-marijuana users to try cocaine. This figure, using data from NIDA’s 1991 National Household Survey on Drug Abuse, is close to being meaningless. It was calculated by dividing the proportion of marijuana users who have ever used cocaine (17%) by the proportion of cocaine users who have never used marijuana (.2%). The high risk-factor obtained is a product not of the fact that so many marijuana users use cocaine but that so many cocaine users used marijuana previously. It is hardly a revelation that people who use one of the least popular drugs are likely to use the more popular ones – not only marijuana, but also alcohol and tobacco cigarettes. The obvious statistic not publicized by CASA is that most marijuana users – 83 percent – never use cocaine. Indeed, for the nearly 70 million Americans who have tried marijuana, it is clearly a "terminus" rather than a "gateway" drug. Click here for a recently-released 12-year study on the subject.
3. Marijuana causes brain damage – The most celebrated study that claims to show brain damage is the rhesus monkey study of Dr. Robert Heath, done in the late 1970s. This study was reviewed by a distinguished panel of scientists sponsored by the Institute of Medicine and the National Academy of Sciences. Their results were published under the title, Marijuana and Health in 1982. Heath’s work was sharply criticized for its insufficient sample size (only four monkeys), its failure to control experimental bias, and the misidentification of normal monkey brain structure as "damaged". Actual studies of human populations of marijuana users have shown no evidence of brain damage. For example, two studies from 1977, published in the Journal of the American Medical Association (JAMA) showed no evidence of brain damage in heavy users of marijuana. That same year, the American Medical Association (AMA) officially came out in favor of decriminalizing marijuana. That’s not the sort of thing you’d expect if the AMA thought marijuana damaged the brain.
4. Marijuana use is increasing at an alarming rate – Reports of slight increases in marijuana use, especially among youth, are being used to convince Americans that a renewed campaign about the drug’s dangers is necessary to avert an impending epidemic. According to government surveys of the general population, marijuana use began decreasing in 1980, after more than a decade of steady increase. By 1990, the downward trend showed signs of slowing, but use-rates remained substantially lower than those recorded in the 1970s. Today 34.3% of high school seniors claim to have smoked pot in the last 12 months which is down from 52.8% in 1976, 50.9% in 1986, and just barely higher than the 33.1% of 1996. See for yourself.
5. Marijuana is more potent today than in the past – This myth is the result of bad data. The researchers who made the claim of increased potency used as their baseline the THC content of marijuana seized by police in the early 1970s. Poor storage of this marijuana in un-air conditioned evidence rooms caused it to deteriorate and decline in potency before any chemical assay was performed. Contemporaneous, independent assays of unseized "street" marijuana from the early 1970s showed a potency equivalent to that of modern "street" marijuana. Actually, the most potent form of this drug that was generally available was sold legally in the 1920s and 1930s by the pharmaceutical company Smith-Klein under the name, "American Cannabis".
6. Marijuana is an addictive drug – It is now frequently stated that marijuana is profoundly addicting and that any increase in prevalence of use will lead inevitably to increases in addiction. Essentially all drugs are used in "an addictive fashion" by some people. However, for any drug to be identified as highly addictive, there should be evidence that substantial numbers of users repeatedly fail in their attempts to discontinue use and develop use-patterns that interfere with other life activities. National epidemiological surveys show that the large majority of people who have had experience with marijuana do not become regular users. In 1993, among Americans age 12 and over, about 34% had used marijuana sometime in their life, but only 9% had used it in the past year, 4.3% in the past month, and 2.8% in the past week. A longitudinal study of young adults who had first been surveyed in high school also found a high "discontinuation rate" for marijuana. While 77% had used the drug, 74% of those had NOT used in the past year and 84% had NOT used in the past month. Compare this to a truly addictive drug, such as the nicotine in smoked tobacco with a 90% addiction rate, and the argument for possible marijuana addiction starts to sound very silly.
7. Marijuana damages the reproductive system – This claim is based chiefly on the work of Dr. Gabriel Nahas, who experimented with tissue (cells) isolated in petri dishes, and the work of researchers who dosed animals with near-lethal amounts of cannabinoids (i.e., the intoxicating part of marijuana). Nahas’ generalizations from his petri dishes to human beings have been rejected by the scientific community as being invalid. In the case of the animal experiments, the animals that survived their ordeal returned to normal within 30 days of the end of the experiment. Studies of actual human populations have failed to demonstrate that marijuana adversely affects the reproductive system.
8. Marijuana suppresses the immune system – Like the studies claiming to show damage to the reproductive system, this myth is based on studies where animals were given extremely high — in many cases, near-lethal — doses of cannabinoids. These results have never been duplicated in human beings. Interestingly, two studies done in 1978 and one done in 1988 showed that hashish and marijuana may have actually stimulated the immune system in the people studied.
9. Marijuana smoke contains over a thousand chemicals – True but very misleading. The 31 August 1990 issue of the magazine Science notes that of the over 800 volatile chemicals present in roasted COFFEE, only 21 have actually been tested on animals and 16 of these cause cancer in rodents. Yet, coffee remains legal and is generally considered fairly safe.
10. Marijuana is a drug without therapeutic value – Proposals to make marijuana legally available as a medicine are countered with claims that safer, more effective drugs are available, including a synthetic version of delta-9-THC, marijuana’s primary active ingredient. For thousands of years, throughout the world, people have used marijuana to treat a variety of medical conditions. Today, in the United States, such use is prohibited. Although 36 states have passed legislation to allow marijuana’s use as a medicine, federal law preempts their making marijuana legally available to patients. People undergoing cancer chemotherapy have found smoked marijuana to be an effective anti-nauseant – often more effective than available pharmaceutical medications. Indeed, 44% of oncologists responding to a questionnaire said they had recommended marijuana to their cancer patients; others said they would recommend it if it were legal. Marijuana is also smoked by thousands of AIDS patients to treat the nausea and vomiting associated with both the disease and AZT drug therapy. Because it stimulates appetite, marijuana also counters HIV-related "wasting," allowing AIDS patients to gain weight and prolong their lives.
