Is Marijuana Use Really Harmful?

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Chapter 2
Is Marijuana Use Really Harmful?

Not everyone agrees that there is such a thing as a "marijuana culture," but when the term is used in the news, it generally refers to a group of people who are marijuana users and who, by their style of dress, music, symbols, and values, intentionally set themselves apart from mainstream society. These marijuana users tend to view people who are anti-marijuana but use alcohol and tobacco as hypocrites. Opponents of this "marijuana culture," on the other hand, feel that since marijuana users do not respect the marijuana laws and encourage other people to use the drug, they are a threat to law-abiding society.

Although the existence of a "marijuana culture" is questionable, the growing number of marijuana users in society is evidence that the popularity of this drug is increasing. It is, therefore, important to determine just how widespread marijuana use truly is, in what ways it is harmful, how serious these threats are, and how they rank compared to alcohol, tobacco, and other illegal drugs. Further, it is important to identify how society acquires its views of marijuana users and how accurate those views are.

How Common Is Marijuana Use?

According to a 1998 federal government survey, marijuana is the most commonly used illegal drug in the United States. This survey found that there were about 2.1 million people who started using marijuana in 1998, and that more than 72 million Americans twelve years of age and older (33 percent of that population) had tried marijuana at least once in their lifetimes. When those numbers are compared to a 1985 survey by the same organization, it is clear that marijuana use is increasing. The 1985 survey found 56.5 million Americans twelve years of age and older (29.4 percent versus 33 percent in 1998) had tried marijuana at least once in their lifetimes. Further, according to the National Institute on Drug Abuse (NIDA), use among high school–aged people alone increased by about 56 percent between 1991 and 1998.

Another indication that marijuana use is on the rise in the United States is the amount of money spent on the drug. Various government agencies report that Americans spend between $7 billion and $11 billion on marijuana each year, and those agencies report that these figures may be low.

Marijuana use is clearly very common, and use is increasing across all social, age, and ethnic groups. During the early part of the twentieth century, for instance, marijuana use in the United States was largely confined to African Americans and immigrants from Mexico, but by the 1970s and continuing into the present, surveys and arrest records show that marijuana users now represent the entire spectrum of American society.

Marijuana in Movies and Music

One of the most common ways that ideas, including ideas about marijuana, spread throughout modern society is by popular entertainment, especially movies and music. Until recently, no far-reaching analysis of how drugs are portrayed in the popular media existed. In 1999, however, the White House Office of National Drug Control Policy (ONDCP) released the first study designed to measure the frequency and nature of illegal drug, alcohol, and tobacco use in popular movies and music. This study determined how often illegal drugs, alcohol, and tobacco were mentioned or shown in movies and music as a first step toward understanding the possible connection between media representations of substances and real-world substance use. The researchers found that an extremely high percentage of the movies studied (98 percent of the two hundred most popular movie rentals of 1996 and 1997) showed tobacco, alcohol, or illegal drugs being consumed. Tobacco and alcohol appeared in more than 90 percent of the movies, and illegal drugs appeared in 22 percent of the movies. Further, one-fourth of the movies depicting illegal drugs contained graphic portrayals of drug preparation and consumption.

Researchers also looked at the thousand most popular songs of 1996 and 1997 and found that more than a quarter of them contained clear references to either alcohol or illegal drugs, although only 2 percent of the songs had substance use as a central theme. Only about a fifth of these songs mentioned any consequences of drug use, being arrested or getting addicted, for example. Use of illegal drugs was associated with wealth or luxury in a fifth of the songs in which drugs appeared, with sexual activity in about a third, and crime or violence in a fifth. The researchers also found that references to drug use were far more common in rap music (63 percent of all rap songs) than any other type of music, including alternative rock (11 percent), top 100 (11 percent), heavy metal (9 percent), or country-western (1 percent).

Although no statistics prove that drug messages in movies and music actually cause drug use, there is a general feeling among many people that the media help shape society's ideas of what is normal and acceptable. If there is such a thing as a "marijuana culture," say the critics, the creators of popular entertainment must accept a good deal of responsibility for creating and spreading it.

Marijuana on the Internet

Marijuana is also consistently one of the top one hundred words looked up on the Internet's search engines. It is possible to find pictures of marijuana, learn how to grow it, find out how to beat a drug test, become a connoisseur of different types of marijuana, chat with other users about their marijuana experiences, buy drug paraphernalia, and even purchase marijuana seeds.

Marijuana Internet sites are about equally divided between those presenting a wide range of information about the drug and those offering marijuana-related merchandise for sale. From smoking paraphernalia to pro-pot T-shirts, marijuana-related products are abundantly available on the Internet. Exact figures on how much money is spent via the Internet on products related to marijuana and other drugs are difficult to determine, but the sites advertising this merchandise number in the thousands.

This particular branch of e-commerce disturbs many people, particularly because so many teens are attracted to it. Statistics show that teenagers spend more time online than any other age group, and the operators of the unregulated marijuana websites appear to recognize this fact. Critics argue that many of the sites direct much of their advertising, by language and images, at kids and teens.

Looking at the prevalence of marijuana-related items and information on the Internet and in other media, many people conclude that there is an organized, highly visible, and active pro-marijuana culture in America. Pro-marijuana messages show up in popular mainstream movies (Saving Grace, Cheech and Chong's Up in Smokeseries, Half-Baked, and Stepmom, to name a few), music, magazines, books, political rhetoric, and television shows (for example, That '70s Show). As a result, several organizations, including the National Institute on Drug Abuse and U.S. Department of Health and Human Services, have begun programs that address this imbalance between pro- and anti-marijuana messages in the popular media to prevent further encouraging youth to embrace marijuana culture.

A "Gateway" Drug?

One of the most common reasons opponents of marijuana view the drug as harmful is that they believe it leads to the use of "harder" drugs such as heroin, LSD, and cocaine. Indeed, numerous studies have found that most users of heroin, LSD, and cocaine used marijuana before they used the more harmful substances. Those studies, however, also found that most marijuana users never go on to use other illegal drugs.

In fact, a large body of statistical evidence actually supports the view that marijuana does not typically function as a gateway drug. As marijuana use in the United States increased during the 1960s and '70s, use of heroin, a strong and very addictive drug, declined. Then when marijuana use declined during the 1980s, heroin use remained fairly stable. In addition, from 1960 to 1990, as the percentage of the American population using marijuana went up and down, the percentage of the population using the drug LSD hardly changed at all. Likewise, cocaine use increased in the early 1980s as marijuana use was declining. And during the 1990s, cocaine use continued to decline as marijuana use increased slightly.

According to the Lindesmith Center–Drug Policy Foundation, of all the high school seniors in 1994 who had ever tried marijuana, less than 16 percent had ever tried cocaine, the drug most often associated with the alleged gateway effect of marijuana. In fact, the proportion of marijuana users trying cocaine has declined steadily since 1986. The Lindesmith Center found no studies whatsoever that linked marijuana use with an increased likelihood of using harder drugs like cocaine and heroin.

In short, numerous researchers have found no evidence that marijuana use inevitably leads to the use of other drugs. The 1999 U.S. government IOM report on medical uses of marijuana states, "There is no conclusive evidence that the drug effects of marijuana are causally linked to the subsequent abuse of other illicit drugs."1

This is the case in other countries, too. In the Netherlands, for example, where marijuana use among young people increased during the 1990s, cocaine use decreased and remains considerably lower than in the United States. In the Netherlands, marijuana is legal if purchased in government-regulated outlets, a policy designed specifically to separate young marijuana users from the illegal markets where heroin and cocaine are sold. The Netherlands was the first country to enact legislation based on the notion that marijuana users would not even be exposed to drugs like cocaine and heroin if marijuana use were legalized, and the Dutch government considers this policy successful in reducing hard drug use.

American proponents of marijuana legalization, like the National Organization for the Reform of Marijuana Laws (NORML), agree with the conclusions of the IOM report and the marijuana policy of the Netherlands. NORML asserts that the real gateway effect of marijuana use is not the result of any tendency of marijuana to make users crave stronger drugs but its illegal status, which exposes buyers to more dangerous drugs on the black market. As long as marijuana is illegal, NORML and others say, users are more likely to be exposed to heroin and cocaine when buying marijuana from illegal sources, because those people are sometimes the same dealers who sell more dangerous, addictive drugs.

Does Marijuana Use Cause Dependence or Addiction?

Most scientific medical evidence indicates that marijuana is not addictive in the way that heroin, nicotine, and other drugs are addictive. Marijuana generally does not make a user's body so dependent on the drug that the person feels physically compelled to keep using it. Nevertheless, all drugs can be used in an addictive fashion by some people, and that includes marijuana. This possibility is another reason marijuana opponents contend that the drug is harmful.

For a drug to be classified as addictive, there needs to be evidence that using it causes substantial numbers of users to fail repeatedly in their attempts to stop using it. Heroin and nicotine, for instance, meet this definition, and both are considered highly addictive. Based on numerous national studies, however, marijuana does not appear to meet this definition of addictiveness.

This is because the great majority of people who have used marijuana do not become regular users. For example, a 1993 report by the Lindesmith Center found that about 34 percent of Americans had used marijuana sometime in their life, but only 9 percent had used it in the past year, 4.3 percent in the past month, and 2.8 percent in the past week. The report also described a study of young adults who had first been surveyed in high school. The study found that even though many students had tried marijuana, most had not continued using it: 77 percent reported they had used the drug—but 74 percent of those had not used it in the past year, and 84 percent had not used it in the past month.

In addition to the Lindesmith Center study, many other private and government research studies have sought to determine if marijuana actually does produce the classic symptoms of addiction in humans, including physical dependence, tolerance, and withdrawal. In 1972 during the Nixon administration, growing marijuana use prompted the federal government to review the existing studies on the drug. After studying all the available information, the government issued a report concluding that marijuana does not possess physically addictive traits. Since then the vast majority of articles published in medical journals have agreed. Two reports in particular—one from the Addiction Research Center (part of the National Institute on Drug Abuse) and another from the University of California—compared the addictiveness of heroin, cocaine, nicotine, alcohol, caffeine, and marijuana. These reports found nicotine to be the most addictive and marijuana the least addictive of the drugs studied. Marijuana also ranked last in terms of producing a physical tolerance to the drug and was deemed least likely to produce signs of withdrawal upon quitting. According to the 1999 IOM report on marijuana's potential medical uses, "Compared to most other drugs. . . dependence among marijuana users is relatively rare. . . . [T]he proportion of marijuana users that ever become dependent is 9 percent of all users, compared to 32 percent of all tobacco users, 15 percent of all alcohol users, 17 percent of all cocaine users, and 23 percent of all heroin users."2

Even so, some researchers contend that there is evidence to show that some marijuana users experience some withdrawal symptoms when they want to stop using the drug. These symptoms are minor, however, when compared to the withdrawal symptoms experienced by users of highly addictive drugs like heroin or nicotine. In the words of the 1999 IOM report, "Although few marijuana users develop dependence, some do. . . . A distinctive marijuana withdrawal syndrome has been identified, but it is mild and short-lived. The syndrome includes restlessness, irritability, mild agitation, insomnia, sleep disturbance, nausea, and cramping."3

Another fact marijuana opponents point to as an indication that marijuana may be addictive after all is the rise in recent years of marijuana addiction treatment programs. At first glance, this would seem to confirm the existence of marijuana addicts, but on closer examination, even this situation is ambiguous. Corresponding to the increase in treatment programs, there has been an increase in drug testing in the workplace, schools, and elsewhere. When an employee fails a drug test by testing positive for marijuana, that person is usually given the option of going to a treatment program, getting fired from the job, or being arrested. Marijuana supporters contend that this choice of options has given rise to an increase in the number of people voluntarily entering treatment programs for marijuana dependence. Neither side yet has unambiguous evidence to support its position.

Does Marijuana Cause Lung Disease?

Marijuana may not be as addictive as some other drugs, but marijuana smoke does contain lung irritants that could increase the risk of lung disease. Although frequent marijuana smokers report respiratory problems like chronic cough, phlegm, and wheezing, clinical studies of daily marijuana users have found no increased risk of serious lung diseases like chronic bronchitis, emphysema, or lung cancer.

In one study, conducted continuously since 1982 at the University of California, Los Angeles, (UCLA) Medical School, researchers have compared marijuana-only smokers, tobacco-only smokers, smokers of both, and nonsmokers. They found that some marijuana-only smokers developed lung problems, but such problems were much less frequent and less pronounced than those found in tobacco smokers. In addition, the impairments found in marijuana-only smokers occurred primarily in the lung's large airways, not the smaller, more delicate airways. Since repeated inflammation of the small airways leads to chronic bronchitis and emphysema, marijuana smokers, the study concluded, are not likely to develop these diseases.

Marijuana is usually smoked unfiltered, which allows more of the tar and other substances found in burning vegetable matter into the user's lungs. Furthermore, because most marijuana smokers inhale deeply and hold the smoke in their lungs for many seconds, more of these dangerous substances are consumed in one inhalation of marijuana than in one inhalation of tobacco. Nevertheless, even a heavy marijuana user smokes the equivalent of only a few cigarettes per day. That may explain why research has not found any evidence that marijuana-only smokers have an increased risk of developing lung cancer. Nevertheless, bronchial cell changes that appear to be precancerous have been seen in some people who smoke marijuana more than twice a day, which indicates that an increased risk of cancer among heavy users is definitely possible. More research, however, will be necessary to confirm this connection.

Does Marijuana Use Lead to Brain Damage?

The lungs are not the only place in the body that marijuana opponents say is at risk from marijuana use. They insist that marijuana use damages a person's brain. But like all issues associated with marijuana use, not everyone agrees.

A research study from the 1970s found structural changes in several brain regions in two rhesus monkeys that had been intentionally exposed to high doses of THC. Because these changes primarily involved the hippocampus, this finding suggested that brain damage (problems with learning and memory) in human marijuana users might be possible. Other studies on mice and rats found similar brain changes. Like many studies on marijuana's effects, however, all of these animal studies required exceptionally large doses of THC to produce observable changes to brain tissues, in some cases up to two hundred times the typical dose used by humans.

Several years later in another study, rhesus monkeys were exposed through face-mask inhalation to marijuana smoke that was equal to four to five joints per day for one year. When the monkeys were analyzed seven months later, the scientists found no changes in the hippocampus structure, cell size, cell number, or nerve connections, suggesting that even heavy marijuana use may not lead to irreversible changes in the hippocampus part of the brain. Because of research like this repudiating earlier reports of brain damage, the 1999 IOM report on medical marijuana concluded, "Earlier studies purporting [claiming] to show structural changes in the brains of heavy marijuana users have not been replicated with more sophisticated techniques."4

Despite this conclusion, opponents of marijuana insist that the research is not complete and that further studies will turn up evidence that marijuana use leads to brain damage. Thus studies continue to explore the effect of marijuana on brain functioning with ever-increasing scientific reliability. These latest studies have found that even though marijuana intoxication does not impair the brain's ability to retrieve information learned previously, it can, particularly when high doses are used, interfere with the ability to transfer new information into long-term memory. Therefore, most researchers conclude that marijuana can temporarily impair some memory functions, but that it does not cause permanent brain damage.

Does Marijuana Affect Male Fertility?

For many years scientists have known that in men, marijuana use also causes reduced fertility. A 2000 study conducted by scientists from the University of Buffalo found definite evidence that marijuana use has caused infertility in some men. This research proved that cannabinoids, both the body's natural cannabinoids and THC from marijuana, can prevent sperm from functioning normally. High concentrations of cannabinoids, for instance, can cause sperm to be less effective at fertilizing eggs. This fact led scientists to conclude that heavy marijuana users may jeopardize their fertility. How often this happens is still unknown, but the lead scientist in the University of Buffalo study stated, "The increased load of cannabinoids in people who abuse marijuana could flood the natural cannabinoid-signal systems in reproductive organs and adversely impact fertility. This possibility may explain observations made over the past 30 to 40 years that marijuana smoke drastically reduces sperm production in males."5

Does Marijuana Use Make People Unmotivated?

Marijuana is also sometimes said to make users passive, apathetic, unproductive, and unable or unwilling to fulfill their responsibilities. This combination of traits is called the amotivational syndrome.

The thought that marijuana causes amotivational syndrome in users first appeared during the late 1960s, as marijuana use was increasing among American youth. Whether or not marijuana makes people less motivated, though, is difficult to test and prove. For example, it is difficult to tell whether an unmotivated person became that way because of marijuana use or if that person was unmotivated for other reasons before ever trying marijuana. In efforts to better understand this issue, researchers conducted several large-scale studies of high school and college students. One study of college students found that marijuana users actually had higher grades than nonusers and that both groups were equally likely to successfully complete their educations. Other studies, these conducted in high schools, found little difference in grade-point averages between marijuana users and nonusers, except that one study found lower grades among students who used marijuana every day. That study's authors felt, however, that it was possible, based on profiles of the students, that the poor grades and marijuana use were part of a bigger set of social and emotional problems.


If there is truly such a thing as the marijuana culture, then its national holiday is April 20, or 4/20. For many years, marijuana users have used the number 420 as a symbol for their drug, and all around the world they have developed a tradition of smoking marijuana at 4:20 p.m. on 4/20. Furthermore, many pro-marijuana organizations hold rallies and lectures on April 20 each year.

There are several theories to explain the origin of 420 as a symbol of the marijuana culture. One theory says that 420 is a police code for marijuana use in some towns. Another theory says it represents the 420 chemical components supposedly found in marijuana. Others believe that a group of students met regularly after school and their meeting time, 4:20, became a symbol of marijuana smoking that somehow spread.

Whatever its origin, for many years 420 was a secret symbol understood only by members of the marijuana culture. Its symbolic meaning eventually leaked out into mainstream society, however, and it has since become commercialized, showing up on clothing, bumper stickers, and other merchandise.

Besides studies comparing marijuana users and nonusers, considerable laboratory research has been directed at finding a link between marijuana use and amotivational syndrome. Most of these studies found that marijuana did not have a significant impact on motivation or learning and work performance. Such results have led researchers to suspect that people with low motivation from nondrug reasons—perhaps because they live with depression, illness, or poverty—are more likely to use drugs, including marijuana. The 1999 IOM report on medical uses for marijuana supported this view, citing statistical evidence suggesting that people with preexisting low motivation levels are more likely to use alcohol and other drugs. The IOM report added that there is no evidence linking low motivation to marijuana use, stating: "When heavy marijuana use accompanies these symptoms [of low motivation], the drug is often cited as the cause, but no convincing data demonstrate a causal relationship between marijuana smoking and these behavioral characteristics."6

Currently available evidence strongly suggests that the health and social risks posed by marijuana are less than previously believed. Nevertheless considerable disagreement remains about whether or not marijuana and the existence of a marijuana culture are harmful.

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Is Marijuana Use Really Harmful?

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Is Marijuana Use Really Harmful?