Marijuana is the
most commonly abused illicit drug in the United States. A dry, shredded
green/brown mix of flowers, stems, seeds, and leaves of the plant
Cannabis sativa, it usually is smoked as a cigarette (joint, nail), or
in a pipe (bong). It also is smoked in blunts, which are cigars that
have been emptied of tobacco and refilled with marijuana, often in
combination with another drug. It might also be mixed in food or brewed
as a tea. As a more concentrated, resinous form it is called hashish
and, as a sticky black liquid, hash oil. Marijuana smoke has a pungent
and distinctive, usually sweet-and-sour odor.
The main active
chemical in marijuana is THC (delta-9-tetrahydrocannabinol). The
membranes of certain nerve cells in the brain contain protein receptors
that bind to THC. Once securely in place, THC kicks off a series of
cellular reactions that ultimately lead to the high that users
experience when they smoke marijuana.
Grass, pot, weed,
bud, Mary Jane, dope, indo, hydro
marijuana is smoked, its effects begin immediately after the drug enters
the brain and last from 1 to 3 hours. If marijuana is consumed in food
or drink, the short-term effects begin more slowly, usually in 1/2 to 1
hour, and last longer, for as long as 4 hours. Smoking marijuana
deposits several times more THC into the blood than does eating or
drinking the drug.
Within a few minutes after inhaling marijuana smoke, an individual’s
heart begins beating more rapidly, the bronchial passages relax and
become enlarged, and blood vessels in the eyes expand, making the eyes
look red. The heart rate, normally 70 to 80 beats per minute, may
increase by 20 to 50 beats per minute or, in some cases, even double.
This effect can be greater if other drugs are taken with marijuana.
THC enters the brain, it causes a user to feel euphoric— or “high”—by
acting in the brain’s reward system, areas of the brain that respond to
stimuli such as food and drink as well as most drugs of abuse. THC
activates the reward system in the same way that nearly all drugs of
abuse do, by stimulating brain cells to release the chemical dopamine.
marijuana user may experience pleasant sensations, colors and sounds may
seem more intense, and time appears to pass very slowly. The user’s
mouth feels dry, and he or she may suddenly become very hungry and
thirsty. His or her hands may tremble and grow cold. The euphoria passes
after awhile, and then the user may feel sleepy or depressed.
Occasionally, marijuana use produces anxiety, fear, distrust, or panic.
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Someone who smokes marijuana regularly may have many of the same
respiratory problems that tobacco smokers do, such as daily cough and
phlegm production, more frequent acute chest illnesses, a heightened
risk of lung infections, and a greater tendency toward obstructed
airways. Cancer of the respiratory tract and lungs may also be promoted
by marijuana smoke. Marijuana has the potential to promote cancer of the
lungs and other parts of the respiratory tract because marijuana smoke
contains 50 percent to 70 percent more carcinogenic hydrocarbons than
does tobacco smoke.
Marijuana's damage to short-term memory seems to occur because THC
alters the way in which information is processed by the hippocampus, a
brain area responsible for memory formation. In one study, researchers
compared marijuana smoking and nonsmoking 12th-graders' scores on
standardized tests of verbal and mathematical skills. Although all of
the students had scored equally well in 4th grade, those who were heavy
marijuana smokers, i.e., those who used marijuana seven or more times
per week, scored significantly lower in 12th grade than nonsmokers.
Another study of 129 college students found that among heavy users of
marijuana critical skills related to attention, memory, and learning
were significantly impaired, even after they had not used the drug for
at least 24 hours.
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Overall marijuana production in Mexico--the principal source of
foreign-produced marijuana to U.S. drug markets appears to be
increasing. Mexico marijuana production estimates indicate that
production in Mexico was relatively low from 2000 through 2002 during a
period of drought, increased sharply in 2003 as weather improved, and
receded slightly in 2004. Moreover, anecdotal reporting and cannabis
eradication and marijuana seizure data all indicate that marijuana
production in Canada has recently increased, perhaps significantly.
Domestic marijuana production also appears to be increasing, according
to law enforcement reporting that reveals a significant increase in
eradication of domestic marijuana grow sites in 2005. Domestic Cannabis
Eradication/Suppression Program (DCE/SP) data indicate that domestic
cannabis eradication--occurring primarily in California, Kentucky,
Tennessee, Hawaii, and Washington, often on public lands including
Forest Service lands increased steadily from 2000 through 2003,
decreased in 2004, and increased sharply to its highest recorded level
of the foreign-produced marijuana available in the United States is
smuggled into the country from Mexico via the U.S.-Mexico border by
Mexican DTOs and criminal groups; however, a sharp rise in marijuana
smuggling from Canada via the U.S.-Canada border by Asian criminal
groups has increased the domestic availability of marijuana produced in
Mexican criminal groups control most wholesale marijuana distribution
throughout the United States; however, Asian criminal groups appear to
be increasing their position as wholesale distributors of
Canada-produced marijuana. According to law enforcement reporting,
Mexican DTOs and criminal groups control most wholesale marijuana
distribution in the Great Lakes, Pacific, Southeast, Southwest, and West
Central Regions and control much of the wholesale marijuana distribution
in the Northeast Region. Although Asian criminal groups are not the
predominant wholesale marijuana distributors in any region, these
groups, particularly Chinese and Vietnamese groups, now are widely
identified in law enforcement reporting as the principal suppliers of
high potency, Canada-produced marijuana throughout the country.
influence of Asian criminal groups in high potency marijuana
distribution is likely to increase in the near term. Law enforcement
reporting indicates that these groups are increasingly gaining control
over much of the high potency marijuana production and distribution in
Canada and now appear to be extending their influence in the United
States. In fact, law enforcement reporting indicates that the influence
of Asian organizations in drug trafficking--particularly the trafficking
of high potency marijuana--in the United States is now more significant
than that of Russian-Israeli, Jamaican, or Puerto Rican criminal groups.
distribution is widespread throughout the country, as evidenced by the
presence of 14 principal distribution centers for the drug, one or more
of which are located in nearly every region of the country. Much of the
midlevel and retail distribution of marijuana in these and other cities
is controlled by African American, Asian, and Hispanic street gangs;
however, independent dealers control most midlevel and retail marijuana
distribution in smaller communities and rural areas. In fact,
independent dealers are likely to retain control of distribution in
smaller communities because they often distribute locally produced
marijuana rather than foreign-produced marijuana.
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students surveyed as part of the 2005 Monitoring the Future study, 16.5%
of eighth graders, 34.1% of tenth graders, and 44.8% of twelfth graders
reported lifetime use of marijuana. In 2004, these percentages were
16.3%, 35.1%, and 45.7%, respectively.
Approximately 74% of eighth graders, 65.5% of tenth graders, and 58% of
twelfth graders surveyed in 2005 reported that smoking marijuana
regularly was a "great risk."
Youth Risk Behavior Surveillance (YRBS) study by the Centers for Disease
Control and Prevention (CDC) surveys high school students on several
risk factors including drug and alcohol use. Results of the 2005 survey
indicate that 38.4% of high school students reported using marijuana at
some point in their lifetimes. Additional YRBS results indicate that
20.2% of students surveyed in 2005 reported current (past month) use of
Between 2001 and 2005, marijuana use dropped in all three categories:
lifetime (13%), past year (15%) and 30-day use (19%). Current marijuana
use decreased 28% among 8th graders (from 9.2% to 6.6%), and 23% among
10th graders (from 19.8% to 15.2%)