 |
|
 |
| |
| MYth |
|
MARIJUANA IS A GATEWAY DRUG.
Even if marijuana itself causes minimal harm,
it is a dangerous substance because it leads to the use of "harder drugs"
like heroin, LSD, and cocaine.
"Marijuana use is on the rise. . . . These findings are especially alarming
since the use of marijuana--the most widely used drug often leads to the use
of other, more dangerous drugs."
"Children who have used marijuana are 85 times likelier to use cocaine than
children who have not used marijuana."
"It appears that the biochemical changes induced by marijuana in the brain
result in a drug-seeking, drug-taking behavior, which in amyn instances will
lead the user to experiment with other pleasurable substances."
"Since marijuana use, harmful as it is in its own right, is often a prelude
to the use of other drugs . . . [it is] doubly disastrous."
"Although marijuana is not as addictive or toxic as cocaine, smoking
marijuana--or seeing others smoke marijuana--might make some individuals
more disposed to use other drugs."
|
| |
| Fact |
| |
MARIJUANA DOES NOT CAUSE PEOPLE TO USE HARD DRUGS.
What the gateway theory
presents as a causal explanation is a statistical association between common
and uncommon drugs, an association that changes over time as different drugs
increase and decrease in prevalence. Marijuana is the most popular illegal
drug in the United States today. Therefore, people who have used less
popular drugs, such as heroin, cocaine, and LSD, are likely to have also
used marijuana. Most marijuana users never use any other illegal drug.
Indeed, for the large majority of people, marijuana is *terminus *rather
than a *gateway* drug.
|
| |
PROPONENTS of the gateway theory, formerly known as the "stepping-stone
hypothesis," argue that even if marijuana itself is not very dangerous,
marijuana leads people to use other more dangerous drugs. In the 1950s,
marijuana was said to be a gateway to heroin, and in the 1960s, a gateway to
LSD. Today, marijuana is discussed primarily as a gateway to cocaine.
People who use cocaine, a relatively unpopular drug, are likely to have used
the more popular drug, marijuana. Marijuana users are also more likely than
nonusers to have had previous experience with legal drugs, such as alcohol,
tobacco, and caffeine. Alcohol, tobacco, and caffeine do not cause people
to use marijuana. Marijuana does not cause people to use heroin, LSD, or
cocaine.
The relationship between marijuana and other drugs varies across societies.
Within the United States, the relationship varies across age groups and
substances, and from one social group to another. Over time, as any
particular drug increases or decreases in popularity, its relationship to
marijuana changes. While marijuana use was increasing in the 1960s and
1970s, heroin use was declining. During the past twenty years, as marijuana
use rates fluctuated, rates for LSD remained constant. Cocaine became
popular in the early 1980s as marijuana use was declining later, both
marijuana and cocaine use declined. Recently, marijuana use ahs increased
while the decline in cocaine use has continued.
Figure 4-1 illustrates the changing relationship between marijuana use and
cocaine use over time. At the height of cocaine's popularity in 1986, 33
percent of high school seniors who had used marijuana had also tire
cocaine. By 1995, only 14 percent of marijuana users had tried cocaine.
Even when marijuana users try cocaine, they do not necessarily become
regular users. In fact, very few do. As shown in figure 4-2, of the
seventy-two million Americans who have used marijuana, about twenty million
have tried cocaine. Of this twenty million, about 30 percent used cocaine
only once or twice. Only 17 percent used cocaine more than one hundred
times. In other words, for every one hundred people who have used
marijuana, *only one *is a current regular user of cocaine.
The probability of trying cocaine is not distributed equally across the
population of marijuana users. Teens who use marijuana occasionally, and
use no illicit drugs other than marijuana, are unlikely to ever try
cocaine. Indeed, most teens who try marijuana never even become regular
users of marijuana. In 1994, among twelve- to seventeen-year-olds who had
tried marijuana, 60 percent had used it fewer than twelve times and about
40 percent had tried it only once or twice.
Studies show that most teens who try cocaine have had many previous drug
experiences. Most began using alcohol and marijuana at an earlier age than
their peers, and most continue to use both alcohol and marijuana
frequently. Most also tried numerous other illicit drugs before trying
cocaine. One study, looking at adults who had been marijuana users in high
school, found that over 80 percent of those who eventually tried cocaine
were already multiple-drug users. They regularly used alcohol, tobacco, and
marijuana, and had also tried stimulants, sedatives, and psychedelics.
Few adolescents become early multiple-drug users, and those who do differ
from their peers in a number of ways. They are more likely to be poor, more
likely to live in neighborhoods where illicit drug use is prevalent, less
likely to come from stable homes, less likely to be successful at school,
and more likely to have psychological problems. Most multiple-drug users
engage in a variety of deviant and delinquent activities prior to using
legal or illegal drugs. In other words, within the general population of
adolescent marijuana users, there is a deviant minority who become multiple
-drug users.
A report by the Center on Addiction and Substance Abuse (CASA) says that
youthful marijuana users are eighty-five times more likely than nonusers to
use cocaine. CASA's calculation is based on marijuana and cocaine
prevalence data from 1991. To obtain the eighty-five times "risk factor,"
CASA divided the proportion of marijuana users who had ever tried cocaine
(17 percent) by the proportion of cocaine users who had never tried
marijuana (0.2 percent). The "risk factor" is large not because so many
marijuana users experiment with cocaine, but because very few people try
cocaine without trying marijuana first.
Recent animal studies showing that THC increases the availability of dopamine
in the brain's "pleasure-reward substrate" are used to claim that marijuana"primes" the brain for heroin and cocaine, drugs which also affect
dopamine's availability in this system. Other researchers have failed to
find dopamine effect from THC, More importantly, there are no studies
showing that "priming" animals with injections of THC increases their
willingness to self-administer heroin or cocaine. After injections of THC,
animals will not even self-administer THC. In short, pharmacological
explanations for a gateway effect from marijuana have no foundation. |
|
| In the end, the gateway theory is not a theory at all. It is a description
of the typical sequence in which multiple-drug users initiate the use of
high-prevalence and low-prevalence drugs. A similar statistical
relationship exists between other kinds of common and uncommon related
activities. For example, most people who ride a motorcycle (a fairly rare
activity) have ridden a bicycle (a fairly common activity). Indeed, the
prevalence of motorcycle riding among people who have never ridden a bicycle
is probably extremely low. However, bicycle riding does not cause
motorcycle riding, and increases in the former will not lead automatically
to increases in the latter. Nor will increases in marijuana use lead
automatically to increases in the use of cocaine or other drugs. |
|
|
|
|
