Marijuana is the most widely used illegal substance in the world today. It's also the most controversial.

According to the 2004 National Survey on Drug Use and Health (NSDUH), approximately 96.8 million (40.2%) Americans ages 12 and older have tried marijuana at least once during their lifetimes. About 25.5 million (10.6%) people reported past year marijuana use, and 14.6 million (6.1%) people reported past month use.

As you might expect, college students use marijuana at higher rates than the U.S. population generally. The Harvard School of Public Health, which has surveyed U.S. college students extensively every other year since 1989, reports that approximately 47% of U.S. college students have tried pot at least once. About 30% report past year use, and 17% report past month use.

Marijuana Quiz: What's Your PQ?

1. Q: Chocolate and marijuana stimulate the same receptors in the brain.
   A: True. However, you would have to eat about 25 pounds of chocolate in one sitting to get the same effect as smoking one joint.



2. Q: Smoking pot kills brain cells and causes brain damage.
   A: False & Undetermined. It probably doesn't kill brain cells, and early studies purporting to show structural changes in the brains of heavy marijuana users have not been replicated with more sophisticated techniques. However, smoking pot clearly interferes with learning and memory. Occasional users experience residual effects on cognitive functioning, including memory, for up to 48 hours after smoking. Habitual users experience ongoing impaired ability to learn new information, which continues for up to several weeks after quitting use.



3. Q: Pot is the most popular illegal drug in America.
   A: True. No other illegal drug challenges pot's popularity in the U.S.



4. Q: Marijuana can be habit-forming but is not addictive.
   A: False. Pot was once considered a non-addictive substance, and many people still believe this. But current research shows that use of the drug by some people can lead to both psychological and physical dependence. A drug is addictive if it causes craving, loss of control, and compulsive use even in the face of negative consequences. Pot meets these criteria. Furthermore, many habitual marijuana users who quit using experience physical withdrawal symptoms that are similar to, though usually milder than, those suffered by cigarette smokers who quit smoking.



5. Q: Smoking marijuana causes laziness and saps motivation.
   A: Undetermined, but it appears to be more false than true. The lack of motivation that some heavy users experience often can be attributed to other factors such as the use of alcohol or other drugs, depression, or other underlying personality characteristics.



6. Q: Marijuana is a "gateway drug." (That is, smoking pot leads to using harder drugs.)
   A: This is most likely false. Most drug users don't begin with marijuana, but start with tobacco and alcohol at a fairly young age. People who go on to use harder drugs tend to be experimenters. Pot is just one of several or many drugs that experimenters may try.



7. Q: Today's marijuana is 10 times more potent than the marijuana of the 1960's and 1970's.
   A: Yes and no. The THC content of regular marijuana has consistently ranged from 2% to 5% in most samples over the past three decades. Several stronger varieties have always been available. These are easier to obtain and more popular today than in past decades.



8. Q: Use of marijuana promotes aggression and crime.
   A: This is generally false. Marijuana usually has a calming effect. Most criminals who use marijuana began committing crimes before they started smoking pot. On the other hand, a couple of studies have shown a correlation between heavy marijuana use in teenagers and aggressive behavior, disruptive behavior, and crime. It's important to note that correlations do not necessarily show cause and effect.



9. Q: Marijuana is classified as a central nervous system depressant.
   A: True to some extent. Marijuana a member of the cannabis family of drugs that also includes hashish, hashish oil, and tetrahydrocannabinol (THC, the main psychoactive substance in the cannabis plant). Medically, it is also classified as a CSN depressant, muscle relaxant, appetite stimulant, hallucinogenic, antiemetic (alleviates nausea and vomiting), and bronchodilator (improves air flow to the lungs).



10. Q: Smoking pot can make you sterile.
    A: Undetermined. More research is needed. We know that many long-term, heavy-using males suffer from a lowered sperm count and slower moving sperm, and some experience impotence. This isn't the same as sterility, which indicates the absence of motile sperm.



11. Q: No one has ever died from an overdose of marijuana.
    A: True. But that doesn't mean that marijuana is safe. There are many risks involved with using marijuana beyond its illegality. People sometimes die as a result of accidents associated with being high on pot.



12. Q: Smoking pot causes lung cancer.
    A: Undetermined. Marijuana smoke and tobacco smoke are known to be similar in several ways. They both contain at least one well-known carcinogen, benzopyrene, and it occurs in greater concentration in marijuana smoke. On the other hand, a recent study at the University of California Los Angeles, found no elevated cancer risk for pot smokers, even the heaviest ones. Apparently, the jury is still out on this one.



13. Q: Smoking pot impairs the immune system.
    A: Unknown. Cannabinoid receptors are highly concentrated in certain immune-system cells as well as in the brain. Researchers have found that THC impairs immune system function in laboratory animals, but the doses in those studies were extremely high. Corroborating research has not been conducted on humans.



14. Q: The effects of smoking pot can last up to two full days.
    A: True. THC, the main active ingredient in marijuana, is extremely fat-soluble, which means it is stored in the body's fatty tissues and can slowly enter the bloodstream for up to two days after smoking.



15. Q: Modern drug testing techniques can identify marijuana in your system up to one month after use.
    A: This may be true for heavy users if the test is particularly sensitive. Most tests, especially those available over the counter, are less sensitive, but even they can detect the presence of THC in heavy users for up to two to three weeks.



16. Q: Smoking pot can make you go crazy.
    A: Go crazy? Probably not. But some pot users experience mild flashbacks, anxiety or panic attacks, and marijuana clearly has been shown to exacerbate certain pre-existing psychological conditions such as anxiety and panic disorders.

Marijuana Basics

How Marijuana Works
HowStuffWorks, a reliable online source for clear, unbiased explanations, offers a lively, in-depth description of marijuana the plant and marijuana the drug.

National Institute on Drug Abuse (NIDA)
NIDA, a division of The National Institutes of Health (NIH), supports over 85 percent of the world's research on the health aspects of drug use, abuse and addiction. Its InfoFacts section on marijuana provides a good description on the effects of marijuana use as well as an extensive bibliography.

The Vaults of Erowid
Erowid provides reliable, non-judgmental information about psychoactive plants and chemicals and related issues. The site includes input from academic, medical, and experiential experts. The comprehensive section on marijuana includes not only general information but also pages on marijuana history and culture.

Marijuana Politics

National Organization for the Reform of Marijuana Laws: NORML
NORML is a nonprofit lobby organization that intends to provide a voice for Americans who oppose marijuana prohibition. NORML supports a policy of decriminalization, the removal of all criminal penalties for the private possession and responsible use of marijuana by adults, including cultivation for personal use, and casual nonprofit transfers of small amounts.

Drug Policy Alliance
The Drug Policy Alliance focuses on marijuana law reform in an effort to end marijuana prohibition in the United States and elsewhere. The project brings together public education efforts, strategic litigation, media outreach and federal and state legislative drafting and lobbying to reform prohibitionist marijuana policies.

Marijuana Policy Project (MPP)
MPP's stated purpose is to develop and promote policies to minimize the harm associated with marijuana. They support research, policy development, lobbying, and educational initiatives.

Texas Statutes: Criminal Penalties

In the State of Texas, possession and/or sale of any amount of marijuana is illegal.

Details
*With no prior felony convictions, if convicted of possession of less than one pound of marijuana a judge must impose a sentence of probation with mandatory drug treatment. If no treatment center exists within the jurisdiction, the judge may waive the treatment requirement. They judge can also waive all fines.

Texas has a marijuana tax stamp law that requires people who possess marijuana to purchase state-issued stamps and affix them onto his or her marijuana. Failure to do so may result in a fine and/or criminal sanction. Although nearly half of all US states have marijuana tax stamp laws on the books, few citizens observe them. Most individuals are unaware that such laws exist in their state; others fear that complying with the law will incriminate them. The legislative intent of drug tax laws is to impose an additional penalty - tax evasion - on drug offenders after they are arrested and criminally charged with a drug violation.

Federal Statutes: Criminal Penalties

Details
*MMS: Mandatory minimum sentence: When someone is convicted of an offense punishable by a mandatory minimum sentence, the judge must sentence the defendant to the mandatory minimum sentence or to a higher sentence. The judge has no power to sentence the defendant to less time than the mandatory minimum. A prisoner serving an MMS for a federal offense and for most state offenses will not be eligible for parole. Even peaceful marijuana smokers sentenced to "life MMS" must serve a life sentence with no chance of parole.

The sentence of death can be carried out on a defendant who has been found guilty of manufacturing, importing or distributing a controlled substance if the act was committed as part of a continuing criminal enterprise, but only if the defendant is (1) the principal administrator, organizer, or leader of the enterprise or is one of several such principal administrators, organizers, or leaders, and (2) the quantity of the controlled substance is 60,000 kg or more of a mixture or substance containing a detectable amount of marijuana, or 60,000 or more marijuana plants, or the if the enterprise received more than $20 million in gross receipts during any 12-month period of its existence.