Just Think Twice. You've heard the fiction, now learn the facts.

Stopping is a good thing as you run the risk of addiction with both. You also risk many other effects to your brain and health. For example, Marijuana can cause some lung problems, like bronchitis. Weed can also be a factor in car wrecks--some 14% of people in car crashes test positive for marijuana (possibly in combination with other drugs). Alcohol is also a big factor in car wrecks. And both marijuana and alcohol can affect a person's ability to learn and remember things--crucial for someone in their teen years especially. Alcohol can also lead to liver problems if abused. So I hope you decide to choose health!

Well - I'm sure that will depend on the circumstances and the police officer. However, your own admission that you have used an illegal substance may be enough for the police to arrest you.

Regardless of personal feelings about the legalization of marijuana, the important thing to remember is that marijuana is a serious drug that can have harmful effects on the brain and body. Teens are at a critical period in the development of the brain. All addictive drugs - including marijuana impact the development of the teen brain and can create problems in function including memory, concentration, decision making, and even the development of addiction. Making marijuana legal might increase its availability and make it more accessible for teens. We have seen this with other drugs - including prescription drugs. The rates of teen abuse and addiction to prescription pain killers and other drugs has risen as the number of prescriptions have risen. Whether you are for or against "legalization" of marijuana increased availability and use by teens would not be good for their health, development, or brains.

I worry about it as a scientist interested in the public's health, so no I don't think so. there are risks of using it, just like with most drugs. For one, you can become addicted although many people don't realize that--about 1 person in 11 whose ever used it will become addicted and the numbers increase when you start young or use it regularly (25-50% of daily users). Did you know that there's a recognized withdrawal syndrome linked to marijuana--its similar to cigarettes--irritability, sleep and appetite problems, and craving--which often keeps people using the drug even when they may want to quit.

I'm doubtful about that, especially in this country where opportunity seems to encourage more and more consumption (of anything). In addition, right now most people stop using marijuana as they get older--responsibilities, not worth the risk legally, etc. If it were to be legal and socially sanctioned more people might continue to use, and more health problems would become evident, including increased numbers of people who become addicted to the drug. Do you think that people you know who use it are doing it to be rebellious?

I don't think so. As a scientist, I worry about the public health downsides to legalizing marijuana. Among them: 1) it is addictive--meaning people can't stop using it even though they realize that its affecting their lives in negative ways--about 9% of users become addicted; 2) it affects driving skills, especially in combination with alcohol (14% of those in fatal car wrecks test positive for THC--sometimes in combination with other drugs); 3) it affects your ability to learn--especially important for someone your age. In regular users, marijuana's effects on memory can be detected days or even weeks later--they are not dramatic, but it can keep you from reaching your full potential, or from keeping your competitive edge in sports, e.g.

No. Mostly because if its legal, it's likely that more people will smoke it more often and that increases the number of people who become addicted to it (about 9% of users become addicted), the number of people that get into car accidents because of it, and the loss of potential in youth who do less with their lives because they choose to use drugs rather than help solve our world's problems.

Smoking marijuana is potentially addictive, is bad for the lungs, and the plant contains more than 400 chemicals with unknown health effects that vary from one plant to the other. Thus, the promise lies in isolating ingredients from marijuana that may have beneficial effects, or in synthetic compounds that act similar to THC (the main active ingredient in marijuana) in the brain and the body. Also, marijuana affects driving skills, especially in combination with alcohol (14% of those in fatal car wrecks test positive for THC--sometimes in combination with other drugs); and it affects your ability to learn--especially important for someone your age. Some states have legalized its use with a prescription for various medical conditions; however, that is not something the Federal government recognizes, since all medicines must get FDA approval based on their safety and efficacy--but marijuana has not met their criteria.

A number of states have chosen to legalize marijuana for medical uses, including California. This is problematic since medicines are supposed to be approved by the Food and Drug Administration (FDA) based on well conducted studies showing them to be safe and effective. Marijuana has not met this requirement. Nevertheless, marijuana does contain ingredients with potential medical uses--especially reducing nausea (from cancer chemotherapy, e.g.), increasing appetite (among those who are suffering from severe malnutrition due to their illness), relieving pain and perhaps other uses as well. But as a plant that is smoked, marijuana is not a great idea for a medicine. Smoking itself is bad for the lungs, and the plant contains more than 400 chemicals with unknown health effects that vary from one plant to the other. Thus, the promise lies isolating ingredients from marijuana that may have beneficial effects, or in synthetic compounds that act similar to THC (the main active ingredient in marijuana) in the brain and the body. This is a very active research area right now.

Hi! Interesting question...hard to answer exactly because marijuana is generally not toxic in the sense that if you smoke it, it is going to kill you. But, if you were to get high and then drive, have unprotected sex, or do something else that could be dangerous, the consequences could be serious.

Thanks for the question. Actually, it is both. We often take drugs because we like the way they make us feel. But recent studies have shown that marijuana itself can be addicting. Hope this answer "shatters a myth"! For more facts and myths, take a look at our latest publication, "DRUGS, Shatter the Myths" You can access this from our National Drug Facts Week web pages at www.drugfactsweek.drugabuse.gov.

Smoking marijuana can cause the following: Short-term effects of marijuana use include euphoria, distorted perceptions, memory impairment, and difficulty thinking and solving problems. Long-term marijuana use, especially in a very young person, can result in a risk for mental illnesses as well as addiction. New research links marijuana use and schizophrenia and/or related disorders. High doses of marijuana can produce an acute psychotic reaction; in addition, use of the drug may trigger the onset or relapse of schizophrenia in vulnerable individuals. Hope this helps.

yes--marijuana makes you high--it doesn't really matter why you are using it. But it depends on how much you smoke and a variety of other factors. You can also get addicted if you use it repeatedly. Also, just fyi, marijuana is not an FDA-approved medication although some states have legalized its medical use

All drugs, including marijuana, affect your judgment and your ability to make good decisions. When people are high they often do things that they normally wouldn't do, including having unprotected sex.

It can be. Research has shown that approximately 9% of people who used marijuana may become dependent. The risk of addiction goes up to about 1 in 6 among those who start using as adolescents, and 25-50% of daily users.

Delta-9-tetrahydrocannabinol (THC) is the main chemical in marijuana that is responsible for the 'high' associated with its use. When marijuana is smoked, its effects begin almost immediately and last anywhere from 1 to 3 hours. THC rapidly passes from the lungs into the bloodstream, which carries the chemical to organs throughout the body. It also binds to special receptors in the brain called 'cannabinoid' receptors, causing changes in lots of brain chemicals, but especially the brain chemical dopamine (which is associated with feelings of pleasure). THC not only acts on brain areas linked with pleasure, but also those linked with learning, memory and coordination. Hope this answers your question! For more information on marijuana, see http://www.nida.nih.gov/MarijBroch/Marijteens.html.

just in the manner in which you introduce marijuana into your body, through the lungs (smoking) vs. through your stomach/intestines (eating). The biggest difference between these two will be the speed with which the drug will enter your blood, brain and eventually reach and impact the brain (and body) functioning. Check out www.marijuana-info.org---it's a site designed for teens.

Yes--its addictive, which means that people have trouble stopping even when they want to and they realize that its affecting their lives in a bad way. As far as "chemically" addictive--well, there is a recognized withdrawal syndrome when regular users stop using the drug. It's not life-threatening like some drugs; it's more like tobacco--people get irritable, can't sleep, lose their appetite, and intensely crave the drug--one of the reasons why its hard for regular users to stop when they want to.

It already is for medical purposes but let me explain this (it's a little complicated). The Food and Drug Administration (FDA), which is responsible for ensuring the safety of everything from cosmetics to human and animal medications to our nation's food supply has not approved marijuana to treat any medical illness. That is because smoking marijuana has not been shown in rigorously conducted studies called, clinical trials, to have medical benefits that exceed its risks--the same standard used to approve any medication. However, the FDA has approved certain medications that contain ingredients found in marijuana. These medications are usually prescribed to relieve symptoms in seriously ill patients, such as reducing nausea for cancer patients on chemotherapy or helping AIDS patients to eat more. Also, there is some new and exciting research looking at the biology of cannabinoids, the general class of molecules related to THC, the active ingredient in marijuana. This research suggests new ways of treating pain and other illnesses without the dangers of becoming addicted or the health liabilities linked to smoking marijuana. See http://www.nida.nih.gov/MarijBroch/Marijteens.html for more information.

That's a great question. The answer is yes for now, and maybe in the future. Right now alcohol is responsible for a much greater proportion of health problems and car accidents than marijuana. Some of that is due to the differing effects of the drugs, but some of it is because many more people use alcohol and do so for their entire lives, so we know about a lot more about its long term effects than we do for marijuana. If marijuana were to become legal, we risk seeing more of its adverse health effects in more of the population--e.g., addiction, lung infections.

This is a great question. Research into the effects of long-term cannabis use on the structure (physical makeup) and function (how it works) of the brain have not given us clear answers. One reason is that we may not have tools sensitive enough to reliably measure the effects. Brain imaging studies in chronic users tend to show some consistent changes in how the brain looks but whether or not that impairs cognitive functioning has yet to be established. Some very recent research in adolescents has shown that even in teens' that haven't smoked marijuana in a month, their brains performed differently compared to teens' that didn't smoke marijuana.

I guess I am a little puzzled by your question. It seems that both ways of taking the drug can get you high and cause problems. I'm not sure what digestive problems you mean, unless you get a bloated feeling afterward, but smoking all by itself is dangerous because you are bringing a lot of other chemicals into your lungs. Marijuana and tobacco smoke both have lots of chemicals in it that may not be psychologically active, but can damage your lungs and may lead eventually to emphysema, lung cancer, or chronic obstructive pulmonary disorder (COPD), all of which make it very difficult to breathe. It seems to me that if you are young and active, then doing things that can compromise your ability to do them is not a wise course of action. Learn more about marijuana at http://www.marijuana-info.org/.

The data on marijuana's negative effects on the brain have been somewhat mixed...some studies showing effects, for example, on learning and some types of memory, and others show little lasting effects. There are other studies showing pretty clear effects on the body. For example, effects on the heart -- here are the results -- marijuana increases heart rate by 20-100 percent shortly after smoking; this effect can last up to 3 hours. In one study, it was estimated that marijuana users have a 4.8-fold increase in the risk of heart attack in the first hour after smoking the drug. This may be due to increased heart rate as well as the effects of marijuana on heart rhythms, causing palpitations and arrhythmias. This risk may be greater in aging populations or in those with cardiac vulnerabilities. Effects on the lungs -- studies have shown marijuana smoke to contain carcinogens and to be an irritant to the lungs. Marijuana smoke contains 50-70 percent more carcinogenic hydrocarbons than tobacco smoke. Marijuana users usually inhale more deeply and hold their breath longer than tobacco smokers do, which further increase the lungs' exposure to carcinogenic smoke. Marijuana smokers show disrupted growth of specific cells in their lung tissue, which could lead to cancer. Nonetheless, marijuana smokers can have many of the same respiratory problems as tobacco smokers, such as daily cough and phlegm production, more frequent acute chest illness, and a heightened risk of lung infections. A study of 450 individuals found that people who smoke marijuana frequently but do not smoke tobacco have more health problems and miss more days of work than nonsmokers. Finally, the effects on daily living -- research shows that marijuana has the potential to cause problems in daily life or make a person's existing problems worse. In one study, heavy marijuana abusers reported that the drug impaired several important measures of life achievement, including physical and mental health, cognitive abilities, social life, and career status. Other studies associate workers' marijuana smoking with increased absences, tardiness, accidents, workers' compensation claims, and job turnover. Hope this helps. For more information check out NIDA's web pages -- www.drugabuse.gov. Go to the drop down menu and select marijuana.

Long-term marijuana use, especially in a very young person, can result in a risk for mental illnesses as well as addiction. New research links marijuana use and schizophrenia and/or related disorders. High doses of marijuana can produce an acute psychotic reaction; in addition, use of the drug may trigger the onset or relapse of schizophrenia in vulnerable individuals. A number of studies have shown an association between chronic marijuana use and increased rates of anxiety, depression, and as I mentioned, schizophrenia. Some of these studies have shown age at first use to be an important risk factor, where early use is a marker of increased vulnerability to later problems. However, at this time, it is not clear whether marijuana use causes mental problems, exacerbates them, or reflects an attempt to self-medicate symptoms already in existence. But don't forget that marijuana has some serious short-term effects too. These include euphoria, distorted perceptions, memory impairment, and difficulty thinking and solving problems. Hope this helps.

Well some of the ingredients in pot may be good for treating certain disease or symptoms--specifically nausea, wasting (severe weight loss) from AIDS, and even pain. That's why there are several medications already available (oral forms of THC) or in the pipeline (a mouth spray) based on these ingredients. But the problem with pot is that 1) its smoked, which is definitely not good for your lungs; 2) its addictive-~9% of users become addicted; and 3) it interferes with learning and memory--particularly crucial for you at this point in your life. Also, because its a plant the ingredients vary from one plant to another, meaning that its not an ideal medicine because you have no consistency in what you are getting. Imagine if someone gave you Tylenol for pain and said that they aren't really sure what dose you're getting or what other ingredients may be in the pill--would you choose that?

Let me start by saying that having concerned friends like you can be really important! Thanks! The short answer is yes, MJ can be addicting...that is, people use the drug compulsively (i.e., like your friend using it almost every day) even though it interferes with family, school, work, and recreational activities. Did you know that almost 10% of people using MJ become addicted to it??? Quitting is not easy either...the cravings and withdrawal symptoms like irritability, sleeping problems, and anxiety can make it difficult for long-term marijuana smokers to quit. Need more information on MJ use and addiction? Check out this resource: http://www.nida.nih.gov/tib/marijuana.html, http://www.nida.nih.gov/PDF/TEENS_Marijuana_brochure.pdf.

We know that there is a whole lot of individual differences (that is, the actual addicting properties of any drug depends on the individuals previous drug history, genetics, biology, etc.). So for some people it is relatively few and others it takes much more drug exposure to result in addiction. For more marijuana info, check out: See http://teens.drugabuse.gov/facts/facts_mj1.php.Hope this helps.

Most likely yes. Everyone is different, so I can't say for sure in his case, but someone who is smoking regularly is likely not operating at their full capacity most of the time. People think the memory impairing effects wear off when the drug is out of the system, but 1) the drug gets absorbed into fat cells and is not out of your system completely for some time; and 2) its effects on memory (and other faculties) can still be detected days and sometimes weeks after last use. The effects may not be as dramatic as meth turning your teeth black, but he may be lessening his chances of living up to his full potential. In fact a study of long time marijuana users (20-30 years) who were asked to report on how they think marijuana affected their lives reported less life satisfaction, poorer mental and physical health, relationship problems, and less career and educational achievement than their peers who came from similar backgrounds. Also, he may be addicted and not even realize it. Can he stop smoking for several weeks if he wanted to?

Marijuana is the most commonly used illegal drug in the U.S, with about 33% of 12th graders reporting using it in the past year. It is made up of dried leaves and other parts of the Cannabis sativa hemp plant. Short-term effects of marijuana use include euphoria, distorted perceptions, memory impairment, difficulty thinking and solving problems, loss of coordination. Some people who smoke marijuana get so they can't stop--they're addicted. You'll find the basics and more about marijuana here: http://teens.drugabuse.gov/facts/facts_mj1.php

Here are some other facts to consider: 1) marijuana is addictive--meaning people can't stop using it even though they realize that its affecting their lives in negative ways--about 9% of users become addicted; 2) it affects driving skills, especially in combination with alcohol--so it may be a contributor to deaths indirectly (14% of those in fatal car wrecks test positive for THC--sometimes in combination with other drugs); 3) it affects your ability to learn--especially important for someone your age. In regular users, marijuana's effects on memory can be detected days or even weeks later--they are not dramatic, but it can keep you from reaching your full potential, or from keeping your competitive edge in sports, e.g. Finally, the potential effects of marijuana on our society are still a matter of heated debate--there are too many unknowns about whether it would really help the economy or whether the black market would simply undercut the cost to stay in the market, thereby decreasing the price overall, and increasing its availability especially to younger people who may not have as much money to spend. In addition the concerns I mentioned above there are others especially in young people who's brains are still actively developing.

Addiction is a serious problem, including addiction to marijuana (more than 4 million people in this country meet clinical criteria for marijuana abuse or addiction), but there are treatments available. Right now they are mostly behavioral, teaching people to recognize what triggers their drug use, and helping them develop skills needed to stop. Also, scientists are working feverishly to develop medications that can help people who are addicted to drugs stop using. But addiction is one of the reasons I am concerned about legalizing marijuana--its likely to just increase the numbers of people with marijuana problems, and I am not in favor of adding to the health problems in this country.

No--different states have different laws about the consequences of possessing marijuana, but California would have been the first state to legalize it for recreational use if Prop 19 passed--which it did not. Some states have legalized its use with a prescription for various medical conditions; however, that is not something the Federal government recognizes, since all other medicines must get FDA approval based on their safety and efficacy--marijuana has not met their criteria.

The average age that people start smoking marijuana is 17 but some kids start a lot younger than that. 15 percent of eighth graders have tried marijuana at least once in their lifetime. That's really scary because the brain isn't fully developed until a person is in their mid-twenties, which means that exposure to drugs during this phase can affect how the brain develops. Also, we know that early drug use is associated with later drug problems. So why take the chance?

I just asked a couple of other experts, and we all agree that there is a chemical in marijuana (probably THC) that acts on the brain to stimulate our appetite.

Tough to answer specifically, because a lot depends on the drug combination and the individual who is abusing the combination. It is a bit like playing "Russian roulette" when we take any substance of abuse, so adding other drugs to that mix can result in a very dangerous combination. BTW, did you know that everybody is NOT doing it. Only about 20% of 12th graders say they have smoked pot in the past month.

THC or Delta-9-tetrahydrocannabinol is the main active ingredient in marijuana, responsible for many of its known effects.

Depends on whether you are a regular user or not, your genes, etc. THC (the main active ingredient in pot) gets absorbed by fat cells and can be released slowly for days after use.

It practically impossible to overdose on marijuana--likely you'll fall asleep before you could consume enough to kill you. On the other hand, marijuana is an indirect contributor to fatalities--especially car crashes. Some 14% of people in fatal car wrecks test positive for marijuana (sometimes in combination with other drugs). And marijuana was involved in more than 370,000 emergency room visits in 2008. So its not without its dangers, although overdose is probably not one of them.

Excellent question, and something that everyone should be aware of. Cannabinoid receptors are now known to play an important role in the development of both the brain and other parts of the body. While we don't know the exact effects that marijuana has on a baby's brain, anyone who is pregnant or thinks they may be pregnant should never take any drugs unless it is prescribed by a doctor. Go here for more: http://www.drugabuse.gov/tib/prenatal.html

Depends--overall about 9% of users become addicted; about 1 in 6 if you start young; and about 25-50% of daily users. But in addition to the numbers, the risks for addiction to weed or any substance depends on a variety of individual factors--your genes (anyone in your family have a drug problem?); the age when you start using; whether you have other mental health problems, like anxiety or depression; etc.

We have found recently in studies that marijuana is in fact an addictive drug. About 9% of those who use MJ become addicted -- that is, it can be extremely hard to stop taking it once addicted. We know that there is a whole lot of individual differences (that is, the actual addicting properties of any drug depends on the individuals previous drug history, genetics, biology, etc.). For more marijuana info, check out: http://teens.drugabuse.gov/facts/facts_mj1.php.Hope this helps.

Actually, several of states have legalized medical marijuana (14 or 15, and it's going through the process of legalization in Washington, DC). Even so, it is not currently approved by the FDA for treating any medical illness. As for the difference, there's no difference in the actual marijuana.

Marijuana affects a number of skills necessary for safe driving--reaction time, attention, motor coordination--and a number of studies have documented its impairing effects on driving simulators or even in road tests. Also, when combined with alcohol the effects are worse than either drug alone. Marijuana users often claim they compensate--by driving slower or leaving more space between themselves and the car in front of them. That may be true, but it won't help in an emergency situation if they have to react fast, and any compensatory behaviors they may exert go out the window when alcohol is involved as well. Approximately 14% of people killed in car crashes test positive for marijuana-although it may be in combination with other drugs.

Excellent question, and something that everyone should be aware of. Cannabinoid receptors are now known to play an important role in the development of both the brain and other parts of the body. While we don't know the exact effects that marijuana has on a baby's brain, anyone who is pregnant or thinks they may be pregnant should never take any drug unless it is prescribed by a doctor. Go here for more: http://www.drugabuse.gov/tib/prenatal.html

Yes. Many more. In 2009, about 104,446 people 12 years old and older reported lifetime use of marijuana, 28,000 reported using in the past year and about 17,000 in the past month. I hope you stay with the majority. Good luck

Addiction--about 9% of users; 1 in 6 of those who start young; and 25-50% of daily users.

Great question. The main difference is that smoking a drug will get it much, much faster to the brain that eating it. But also, and equally important, when you eat the drug the digestive system will have a chance to destroy some of the drug, so less of it will reach the brain.

Good question - and one that is frequently misunderstood. Pot, marijuana or cannabis are drugs that build up in your body if you use them frequently. Pot is a drug that likes to be stored in fat. If someone is an occasional user, your urine is usually only positive for one or two days after your last use, but if you use on a daily basis, you build up a large body burden of the drug that is excreted over weeks. This residual drug also continues to affect you while it is in your body, including your brain. Recent research shows that your urine, blood and saliva can be positive for weeks after last use. You might find this website of interest: http://www.marijuana-info.org/.

Fascinating question - and this is one of the truthful folktales about marijuana. Whenever someone smokes marijuana they are taking over one of the most important systems in the body. This system affects your short term memory, body temperature, some aspects of reproduction, and hunger. It also produces the effects of euphoria and relaxation. So in essence smoking takes over or highjacks the normal functions of this system. Therefore, you stimulate the receptors in your brain that tell you you are hungry. Another example that the drug is affecting the normal functioning of your brain. You might find this additional info on marijuana interesting: http://teens.drugabuse.gov/facts/facts_mj1.php.