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Marijuana (pot, weed, grass, reefer, herb, green, joint, bong toke) is the common name for a crude drug made from the plant Cannabis sativa. The main mind-altering (psychoactive) ingredient in marijuana is THC (delta-9-tetrahydrocannabinol), but more than 400 other chemicals also are in the plant. A marijuana "joint" (cigarette) is made from the dried particles of the plant. The amount of THC in the marijuana determines how strong its effects will be. The type of plant, the weather, the soil, the time of harvest, and other factors determine the strength of marijuana. The strength of today's marijuana is as much as ten times greater than the marijuana used in the early 1970s. This more potent marijuana increases physical and mental effects and the possibility of health problems for the user. Hashish, or hash, is made by taking the resin from the leaves and flowers of the marijuana plant and pressing it into cakes or slabs. Hash is usually stronger than crude marijuana and may contain five to ten times as much THC. Pure THC is almost never available, except for research. Substances sold as THC on the street often turn out to be something else, such as PCP.

What are some of the immediate effects of smoking marijuana?

Many feelings experienced by marijuana users are subjective in nature. Feelings may include euphoria, relaxation and hilarity, and negative psychological reactions include panic attacks, anxiety and hallucinations. A common bad reaction to marijuana is the "acute panic anxiety reaction." People describe this reaction as an extreme fear of "losing control," which causes panic. The symptoms usually disappear in a few hours. Although it is difficult to measure objectively, researchers have expressed concern over marijuana's effects on motivation. A picture has emerged of amotivational syndrome, which can be described as a massive and persistent loss of ambition that is replaced by chronic apathy and passivity toward goals and the future. Amotivational syndrome is seen most frequently in heavy marijuana users.

Some immediate physical effects of marijuana include a faster heartbeat and pulse rate, bloodshot eyes, and a dry mouth and throat. Marijuana also produces inability to complete psychomotor tasks. Driving performance is impaired, due to altered perception of space and time, and the ability to make quick decisions is reduced. Marijuana intoxication interferes with other skills such as communicating, or recalling verbal or graphic material from short-term memory. The degree of impairment depends on the dose and potency of the drug, the individual's tolerance, and the complexity of the task. Studies of marijuana's mental effects show that the drug can impair or reduce short-term memory and alter one's sense of time. A study of college students has shown that critical skills related to attention, memory, and learning are impaired among heavy users of marijuana, even after discontinuing its use for at least 24 hours. No scientific evidence exists indicating that marijuana use improves hearing, eyesight, and skin sensitivity.

What other physical problems does marijuana cause?

Marijuana use increases the heart rate as much as 50 percent, depending on the amount of THC. It can cause chest pain in people who have a poor blood supply to the heart - and it produces these effects more rapidly than tobacco smoke does. In addition, several facts about marijuana smoking have produced persistent concern about its effects on the respiratory system. First, marijuana is smoked "unfiltered," and the cigarette is consumed almost entirely. Also, when smoked marijuana is deeply inhaled, and the smoke is held in the lungs for several seconds. Therefore, the smoke is in contact with lung tissues for long periods of time, which irritates the lungs and damages the way they work. Marijuana smoke contains some of the same ingredients found in tobacco smoke that can cause emphysema and cancer. Ingredients include carbon monoxide, nitrosamines, benzopyrene, and over 60 cannabinoid compounds. All of these are respiratory irritants and potential carcinogens. Users have reported symptoms such as hoarseness, coughing, laryngitis and bronchitis.

In addition, many marijuana users also smoke cigarettes; the combined effects of smoking these two substances creates an increased health risk. Long-term use of marijuana has been shown to produce precancerous cell changes and several recent studies suggest that marijuana smoking can lead to lung cancer. Examination of human lung tissue that had been exposed to marijuana smoke over a long period of time in a laboratory showed cellular changes called metaplasia that are considered precancerous. In laboratory test, the tars from marijuana smoke have produced tumors when applied to animal skin. These studies suggest that it is likely that marijuana may cause cancer if used for a number of years.

In addition to irritation of the respiratory system, specific physical effects of chronic marijuana use include impairment of the immune system. Also, there is evidence that regular marijuana use may damage the reproductive system, including reducing sperm production, decreasing estrogen production, and causing menstrual or ovulatory irregularities. Research on marijuana use during pregnancy is inconclusive, although like most substances, marijuana crosses the placental barrier. Evidence suggests that marijuana use during pregnancy may be sufficient to produce permanent fetal abnormalities, and may increase harm to the fetus greatly if combined with other drug use, inadequate prenatal care, or malnourishment. Some research studies suggest that the use of marijuana during pregnancy may result in premature babies and in low birth weights. Studies show that men and women may have a temporary loss of fertility. These findings suggest that marijuana may be especially harmful during adolescence, a period of rapid physical and sexual development.

How long does marijuana stay in the body?

Marijuana is highly fat soluble, and thus it is absorbed readily into fat cells in the body and will accumulate in the brain, liver, lungs and reproductive organs. These parts of the body are covered by fatty membranes. As a result of this storage within the body, marijuana poses serious danger because its effects may persist for several days or even weeks with chronic use. When marijuana is smoked, THC, its active ingredient, is absorbed by most tissues and organs in the body; however, it is primarily found in fat tissues. The body, in its attempt to rid itself of the foreign chemical, chemically transforms the THC into metabolites. Urine tests can detect THC metabolites for up to one month after having smoked marijuana.

Is marijuana addictive?

Addiction refers to the development of a physical and/or psychological dependence to the use of a substance. The first sign of physical dependence is tolerance. Tolerance to a drug develops when increasing doses of a drug are required to produce the same effect. If marijuana use is infrequent or doses are small, tolerance to the drug is not apparent. After prolonged use, however, it is necessary to ingest more marijuana to produce the same feelings. The fact that the body stores THC may be a factor in developing tolerance. In addition to signs of tolerance, physical dependence also is manifested when an interruption of drug use produces physical withdrawal symptoms. Marijuana use is not commonly considered to cause significant withdrawal symptoms, although many users report physical symptoms associated with stopping their use after using frequently and in high doses. Those symptoms include depressed mood, irritability, sleep disturbance, changes in appetite, among others.

Can users of marijuana become psychologically dependent?

Because of the "good feeling" and instant gratification that marijuana can produce, psychological dependence is a very real consequence. Moreover, the lack of motivation that also is experienced by regular users may make it even more difficult to discontinue using marijuana. Long-term regular users of marijuana often become psychologically dependent on continued use. They may have a hard time limiting or controlling their use, they may develop problems with their school work, jobs and personal relationships, and they may continue using in spite of these problems. They also may become preoccupied with using, and in some cases the drug becomes the most important aspect of their lives. These are all clear signs of dependence on marijuana.

What are the dangers of marijuana use for young people?

One major concern for marijuana use is its negative effects on young people as they grow up. Research shows that the earlier people start using substances like marijuana, the more likely they are to go on to experiment with other drugs. In addition, when young people start using marijuana regularly, they often lose interest and are not motivated to do their school work. The effects of marijuana can interfere with learning by impairing thinking, reading comprehension, and verbal and mathematical skills. Research shows that students do not remember what they have learned when they are "high". They also no longer engage in other maturity inducing activities, such as sports, hobbies or intimate relationships.

How does marijuana affect driving ability?

Driving experiments show that marijuana affects a wide range of skills needed for safe driving -- thinking and reflexes are slowed, making it hard for drivers to respond to sudden, unexpected events. Also, a driver's ability to "track" (stay in lane) through curves, to brake quickly, and to maintain speed and the proper distance between cars is affected. Research shows that these skills are impaired for at least 4-6 hours after smoking a single marijuana cigarette, long after the "high" is gone. If a person drinks alcohol along with using marijuana, the risk of an accident greatly increases. Marijuana presents a definite danger on the road.

How are people usually introduced to marijuana?

Many young people are introduced to marijuana by their peers - usually acquaintances, friends, sisters, and brothers. People often try drugs such as marijuana because they are curious about its effects, and because they feel a need to be part of the group. Children must be taught how to say no to peer pressure to try drugs. Parents can get involved by becoming informed about marijuana and by talking to their children about drug use.

What is marijuana "burnout"?

"Burnout" is a term first used by marijuana smokers themselves to describe the effect of prolonged use. Young people who smoke marijuana heavily over long periods of time can become dull, slow moving, and inattentive. These "burned-out" users are sometimes so unaware of their surroundings that they do not respond when friends speak to them, and they do not realize they have a problem.

MYTHS & FACTS ABOUT MARIJUANA:

MYTH: Marijuana is safe because it is a plant.

FACT: Many plants are toxic and unsafe for human use, including marijuana. Some natural plants, including some mushrooms, are deadly, with no avialable antidote once they are consumed.

MYTH: Marijuana users do not go on to use other drugs.

FACT: Studies show that marijuana users have a predisposition to use other drugs. Most heavy drug users started out using marijuana.

MYTH: Marijuana wears off in a few hours.

FACT: Because marijuana is stored in the fat cells of the body, its effects may be felt for days or weeks following ingestion.

MYTH: Marijuana relieves stress.

FACT: Marijuana, like all drugs, merely postpones coping with problems and deadlines; marijuana use can lead to depression.

MYTH: Marijuana is safer than alcohol.

FACT: Marijuana contains carcinogenic chemicals, and it is a dangerous substance that should not be considered a "safe" alternative to other substances.

MYTH: Marijuana expands the mind.

FACT: Marijuana clouds the mind, interfering with memory, speech, comprehension and decision-making ability, and the effects can last for days or weeks.

MYTH: Marijuana today is safer than earlier varieties.

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