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Drugs & Health Blog

Real Teens Ask About Marijuana

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Sara Bellum

In a recent Drug Facts Chat Day, Jiacalone_01 from Cashmere High School in Washington asked: What percentage of 9th graders smoke marijuana?

Not So Popular

Most teens are not smoking marijuana. We know this from asking teens themselves. How? Through the annual survey of teen drug use called Monitoring the Future, which surveys 8th, 10th, and 12th graders about their drug use and attitudes. The survey found that about 12 percent of 8th graders reported marijuana use in 2009 compared to about 27 percent of 10th graders and 22 percent of 12th graders. 

The survey also showed that marijuana use has declined steadily since the mid-1990s until about 2002. Since then, it’s kind of leveled off, so the people here at NIDA are trying to figure out why, and how to get things back to a downward trend.

The ABC's of THC

One reason for the leveling off may be something else the survey found—which is a change in attitudes among teens toward marijuana smoking—that they consider it to be less harmful than they did in years past.

The thing is, marijuana is more than just a mix of dried leaves from the cannabis sativa plant. It actually contains a chemical called delta-9-tetrahydrocannabinol, or THC, along with about 400 other chemicals. Although many of these can affect your health, THC is the main psychoactive (i.e., mind-altering) ingredient. (In fact, marijuana’s strength or potency is related to the amount of THC it contains, which is something people who use marijuana won’t know since it's an illegal substance.)

THC alters the way your brain functions, which can be bad news for teen brains since they’re still developing. For example, THC can disrupt what goes on in your hippocampus, which can lead to problems with learning and memory—since that’s what this brain area gets involved in. Disrupting its normal functioning can lead to problems studying, learning new things, and recalling recent events.

Get the Facts

You can read more on marijuana here:

P.S. Some people argue that marijuana is not addictive. Wrong! In 2007, the majority of youth (age 17 or younger) entering drug abuse treatment reported marijuana as their primary drug abused. We admit that, we still don’t know everything that marijuana use does to teens. But we do know that adolescents’ brains are still growing and changing—so is it really worth the risk?

Comments posted to the Drugs & Health Blog are from the general public and may contain inaccurate information. They do not represent the views of NIDA or any other federal government entity.


I don't think that teenagers should use marijuana any more than they should use any other drug. However, it's difficult to convince them that marijuana is so bad when cigarettes and alcohol, both legal substances, cause just as many or more stated long term problems. Marijuana, cigarettes and alcohol are all illegal for teenage consumption, yes, but only marijuana is illegal for adults, too. Considering that teens are particularly alive to adult hypocrisy, how can we possibly convince them that marijuana is so bad when it's stated long term side effects are equal to or less than drugs they'll be able to legally consume after reaching adulthood?

@Donald--agreed, many legal drugs can cause a lot of damage, particularly cigarettes and alcohol, as you mention. And that's why we also work to prevent teens from abusing legal drugs as well as illegal ones. Here's some info on tobacco and alcohol, for example.

excuse me my friend whos 15 and smokes once a month does that affect his learning or anything permanent

Drug use can have consequences, even smoking marijuana occasionally. To learn more, check out our Marijuana Drug Facts page:

It sounds like you care about your friend. Figuring out what to do when someone you know is having trouble with drugs can be tricky. You want to help, but you might not know how to bring it up. Here are some tips.

Listen without making judgments.

Share scientific information about what drugs can do to a person. Get the latest on how drugs affect the brain and body here: Once your friend understands how drugs affect the brain, body, and life, it might open their eyes.

You should also talk with your parents, a trusted adult, or the school guidance counselor for advice.

please help me? after a month i stop smoke weed why today is back when im eating.. how to remove it? pls help me? While eating I'm returning dizziness and dryness...

@KEVIN KENNETTE If you are looking for help staying away from marijuana you can use SAMHSA’s online Substance Abuse Treatment Facility Locator ( or call 1–800–662–HELP to tap into a support network where you can find immediate and confidential help 24/7. They will also be able to direct you to local treatment options. Good luck!

Marijuana addiction treatment is not a quick and easy process. In general, the longer and more intense the Marijuana use, the longer and more intense the treatment you’ll need. But regardless of the treatment program’s length in weeks or months, long-term follow-up care is crucial to recovery.

True but when you think about it I would rather have someone smoke than use marijuana. But its just a dumb thing to even think about.

Is there really someone named Sara Bellum? Just curious

@LEARNtheFACTS--Sure there is. She's been around NIDA for years and years. :)

This is a blatant example of abusing the facts. In your article you say that marijuana CAN do this and CAN do that, but nothing is definitive. It has been proven that marijuana CAN (see what I did there, i can use general phrasing too) be used as medicine for pain relief as well as many other medical uses. Why do you fail to mention this? Also, you say that most teens are not smoking marijuana. This data is most likely not accurate. Who is collecting the data, other kids? I think not. If you were a teen and an adult asked you whether or not you did drugs, even if it was anonymous, what motivation would you have to answer yes. Even they did do drugs they would say no because there is very little incentive for them to answer yes. Either you answer no and have no change of getting in trouble with school/law/parents or say yes and have a chance of getting in trouble. I know which one I would choose.

Please stop distorting facts and figures to convey your personal view on marijuana

@Chris: NIDA depends on huge national surveys given anonymously to teens each year. These surveys reach over 48,000 teens. Research shows that teens are actually likely to be truthful in such surveys, where they can answer anonymously, than in other methods of gathering personal information. Also, the results show unusual uniformity across different kinds of big national surveys, which further supports the findings. Often, our personal experience of the world doesn't line up with the larger trend. About medical uses--I addressed a comment already on the medical uses of THC, the active ingredient in marijuana, which you correctly note do exist. The blogs usually focus on one main topic, so hard to cover everything in every post.

@Donald yeah I agree also to you donald...that there are too many substances that legally accepted but damages the life..marijuana is better than cigarettes..but instead of doing some drug thing why not trying a new hobby like [body building] {edit: removed commercial link per guidelines] or doing sports?

Most teens are to smoking marijuana, I know this because i'm a teen myself and I used to smoke pot until I had an anxiety attack I thought I couldn't breath, I was wheezing, and I witnessed high levels of parnoia! teens tell you they dont smoke weed because they lie to you trust me I used to lie all the time about what I did or did not do, and that's how all other teens are like so we need to help them while we still got a chance to save thier lives.

yes there are health risks to using any drug and anything you can do, walking, running, sex. with that said the risks are far from equal to the rest, it is in fact much lower especially when it comes to death. everything i know of that is a drug or not has a much lower lethal dose. that 2007 report on the addiction of pot is far from bias. the reason so many teens abuse it is its the lesser evil of the legal and illegal, i have yet to meet someone that gave sexual favors for a hit of pot. i do have a question though, why do you say that a pot user wouldn't know about thc and its play in potency? everyone knows about thc and its potency, why do you feel its necessary to slander pot users this way? to be honest allot of them are smart people. and on a closing note pot is much less addictive than other abused drugs, caffeine is far more addictive. could it possibly be that people see less harm to others from pot when compared to other drugs? did you know that the prohibition of pot since the drug testing phase of business started has made cocaine and other harsh more popular due to the fact that pot can be detected much later than it counterparts?

@kcdude53: the reason NIDA talks about the unknowns of pot potency is because it is hard to know with any particular "sample" of marijuana the makeup of chemicals and other ingredients--which can make it potentially dangerous since you don't ncessarily know what you're getting each time. And even though pot may be less addictive than other drugs, it can still be addictive and, beyond that, cause other problems related to memory, motivation, coordination, etc. These effects can lead to not doing as well in school or to things like impaired driving, which then can lead to criminal justice and other consequences especially hard on teens. Cocaine and pot can both be detected by urinalysis up to 3 days for casual use.

Tell the teenagers the truth about marijuana and think for yourself do some research and learn the truth about the medical affects so we can stop denying ourselves the massive amounts of resources possible through the industrial growth of hemp for fuel, a fiber, and better quality quickly renewable supply of building materials (12" blocks of hemp mixed with lye are 6 times lighter then concrete, have an insulation value of R-28, is fire resistant, and is recyclable.

New Biologically Active Compounds from Cannabis

Humans have been using cannabis for thousands of years for medical treatments, spiritual purposes, textile manufacturing, and other reasons. In recent history, chemists have isolated many cannabinoids, the metabolites in cannabis sativa, and have described some of their biological activities. For example, some cannabinoids have potent effects on multidrug resistant bacteria and others are effective against pain. The structures of known cannabinoids also inspire chemists to create synthetic chemicals to mimic certain aspects of their function, like pain reduction, while providing a powerful medical effect and avoiding negative side effects.

Although a lot of work that has been done on cannabis, scientists have not identified every cannabinoid, so many research groups are continuing to identify and categorize the chemicals in cannabis. Samir Ross from the University of Mississippi led one such group in the discovery of nine new cannabinoids, and they published the structures and biological activities of these chemicals in an advanced article in the Journal of Natural Products.

The researchers grew plants from high-potency Mexican C. sativa seeds and harvested the whole buds of mature female plants. They performed chemical extraction and purification procedures on the plant material to isolate the nine cannabinoids. They then determined the molecular structures of these new chemicals using a variety of techniques, including 1D and 2D NMR, UV, and HRESIMS (high resolution electron spray ionization mass spectra).

After figuring out the chemical structures, it was crucial to know how useful these molecules might be in terms of medicinal properties. The first good news was that none of the cannabinoids were toxic to cells extracted from African green monkey kidneys, which meant that they have potential as drugs. Upon closer inspection, several of the compounds had respectable biological activities, as well.

Compound 5 had potent antileishmanial activity, which makes it a possible candidate against leishmaniasis, a parasitic disease that is spread by the bite of the sandfly. Compound 8 was effective at killing Staphylococcus aureus, a frequent cause of staph infections, and compound 7 had good activity against Candida albicans, a fungus that gives people oral and genital infections. The other cannabinoids weren’t as biologically active, but they all had some drug potential. For insistence, compounds 2 and 6 were mildly affective against MRSA, and compound 1 had some antimalarial activity.

The identification of these biologically relevant cannabinoids will give natural product chemists new ideas for future drugs. Even the less active ones can turn out to be useful, as chemists can make modifications of the structures that are more potent.

@Locked Llion: no doubt that research has shown marijuana has medicinal properties. THC, the main active ingredient in marijuana, produces effects that can potentially treat a variety of medical conditions. THC is the main ingredient in an oral medication currently approved to treat nausea in cancer chemotherapy patients and stimulate appetite in patients with wasting syndrome due to AIDS. Also, since cannabinoids can affect the immune system, cannabinoid-based drugs may be useful in managing autoimmune diseases, where the body's own immune system breaks down. Scientists are continuing to investigate other potential medical uses for THC and other cannabinoids in the marijuana plant.

The value of smoked marijuana, though, is a little less clear, because the potential harm from inconsistent ingredients and chemical concentrations in different marijuana samples, not to mention from the smoke itself, could override the potential benefits. Most everyone recognizes that we need more research to clarify the positive health effects of marijana and to develop safer formulations and delivery methods--beyond smoking. So once again, good science will have to come before policy changes.

LockedLlion says:
Thank you. Your comment is awaiting moderation.
May 8, 2010 at 7:03 pm
New Biologically Active Compounds from Cannabis
what do you guys screen the facts that you will post on your site I sure hope you aren't that bias.

muffin, its not about saving lives, i hate that you were one of the rare cases with realy bad adverse reactions but i highly doubt it would have killed ya, heck you would have ben the only recorded fatality due to pot. nidawriter, your right, we dont know what we are getting each time, as far as potency the experienced user can tend to smell a difference between weak and strong pot and as far as chems that dont belong would be eliminated by legalizing it. as far as the addictiveness goes it is nothing compared to crack, heroine, alcohol, tobacco, even less addictive than caffeine, so saying its addictive is flawed unless you mention the fact that video games, computers, tv, working and exercising are just as addictive if not worse. what i meant about the comparison to cocaine as far as drug tests go is this,
#1 pot is detected in urine for 2-3 weeks in most individuals
#2 coke and other illict drugs tend be detected in urine for 2-4 days in most individuals
#3 due to pot being detected longer and the fact that alot of people want good jobs and to get messed up, they turn to coke and other harsher drugs, so that they can get messed up friday night and pass a pee test no later than Wensday if it even takes it that long.
conclusion: pot being illegal + passing a pee test is becoming more necessary for the work force = more demand for coke and other hard drugs.
now as far as side affects go yes that does happen but how bad it happens and wether it lingers with ya depends on your smoking habit, the casual or once in awhile smoker may have these broblems while high but will not see lasting affects, the daily light smoker meaning .5-1.5 grams a day may see have these problems while high but not as bad as the casual and chances are it wont linger, now with heavy smokers meaning they stay baked are the people that you are realy dealing with when it comes to these problems, but if they stop for some time it will usually start getting better after week 1 even if they just go back to being a light smoker the long term problems tend to fade. but lets be honest these are also symptoms of cafeine and nicotene withdraws witch can be as devisting to a teens life if it is not legal related. legal issues are the main threat that pot has to its users and its insane that pot has "no medical use" while coke and opiates do. and marinol is not very affective and most of its users go back to pot due to its lack of performance and that it makes alot of them scary high. as far as needing to isolate and identifie how ever canabinoid works, no. concintrating the individual chems for a medicine may do to pot what it did for cocaine, cocaine is as harmful as it is due to purity, in its plant form its nowhere near as harmful. i think pot works as well as it does due to the many different chems that make it. personally i love science and would love to see how all the diferent banoids work by themselves and together but sceince dismanteling it for medicine rather than leaving it in its natural form is as scary as giving a kid ridalin or adderal, as far as other systems to take it, you can eat it but the affects are stronger last longer and takes longer for an affect, you can vaporize it and it wont burn the plant material but has a different feel than smoking it. but to realy do it justice it should be legal, it will open jobs, cut back on victamless crimes thuss freeing jails and prisons for actuall bad people, open up jobs for people who use it responcibly, and can help the environment by reducing the use of materials that mess with it, and help improve the lives of people who can be helped without the use of hard drugs like oxycottin, adderal, morphine, and many more drugs that are not just highly addictive but can easily be fatel or cause conditions that will worsen the quality of life for the person who is already suffering.

I'm doing my senior project on teens issues dealing with everyday issues that all teens go through and im stuck with 2 questions can anyone help me? what cause major issues for while using drugs, what are other ways that i a mentor can do to help the teens in my community with drug problem.

@teenmentor10--Sure! But can you clarify what you need? Are you saying: what are the major issues behind why many people use drugs?--or do you mean what happens in the lives of people who get addicted? Or what are the consequences of using drugs? Sorry, just not far as being a mentor to teens with drug problems, you might see what groups are active in your community--ask your guidance counselor or a local church mission or even a community volunteer coordinator. Do a key word search with your community in the string. Good luck.

As substance abuse counselor and a person in recovery, I am very much aware of potential dangers of Marijuana. However, whenever a source, such as this cites "the majority of youth (age 17 or younger) entering drug abuse treatment" as an authority on what is addictive I recognize a species argument when I see it. So to will all of my clients and young people in general. This is lazy rhetoric that only raises the anti-authoritarian stance of those who wish to minimize the potential dangers of marijuana.

@TGratch--sorry, did not mean to sound "specious," but that's the data. It's from the Treatment Episode Data Set, or TEDS, which I'm sure you're familiar with. Here is the table that shows percentages of which drugs different ages are reporting to treatment for. Marijuana is #1 for teens.

It's good to know that some people in this world or in this discission is educated on marijuana. first thing i would like to say is if there is 400 (or any other ridiculious number) of chemicals in marijuana what are they? do they really exsist? and if they do why dont you give us an example of the names of these chemicals? they cant because its a scare tatic for people not to smoke pot. Also if marijuana is as bad as any other drug (claimed by "proffessionals") then whats the annual death rate? tobacco kills at least 450,000 (it can be proven) alcohol kills 250,000 (can be proven) marijuana kills 0 people (no recorded deaths) so if both tobacco and alcohol can kill 700,000 people combined, how and why are these drugs still legal and getting money? THC yes the main thing in marijuana, yes it can mess with your brain causing effects but its not its effects that make it illegal (because if it was it wouldnt be in any medical practice) its the way people use it that makes it illegal such as transporting it in large quantities, smoking large quantities, smoking for any emotional reasons. The way people abuse it is forming an addiction and the way that could happen is doing the drug for any emotion reasons or having an overactive curiosity for the drug, thats how a dependancy gets formed, its never good to try or do a drug without proper knowledge of it. last thing im going to say and im done parents if you know that dangerous things like drugs are out there, educate your kids as soon as they're at a age they know what they're doing (7-11) dont lie to them, give them the straight facts about it and the straights consequences about it because thats the first place it starts, so overall just let them know its out there and give them good knowledge about what can possibly happen if they do it.

@Ryder--No one at NIDA is trying to fool anyone, just doing what you recommend in your last sentence: getting out the "straight facts" and the "straight consequences." Sorry, you cannot connect "0" deaths with marijuana use. For one thing, up to 11% of people who die in car wrecks test positive for THC in their blood.

What a great site - therev are a million things to do that are more fun then smoking some unknown grass.
go to the beach, go to the movies, go to the gym - you are not missing anything. [Deleted commercial link, per g/l]

At the person who said i would rather have someone smoke cigarettes then smoke marijuana. I think, personally, that is stupid. Both of my parents smoke cigarettes and are hopelessly addicted to nicotine. But i also have a lot of friends that smoke marijuana and have not shown any addictive behavior I know many people that smoked marijuana for 4+ years everyday for that matter, and still had little to no trouble stopping. Of course marijuana is addictive and does do damage to a teens brain but the addiction is mild and the brain damage is not nearly as severe as other substances, or even falling and hitting your head can be more severe. But even when a person is addicted to marijuana and they stop there withdrawal symptoms include: headaches, and temporary loss of motivation. But take alcohol withdrawals, they can kill you, literally kill you. Now granted i am just a kid but even i know that that is a stupid decision of our government/states to keep alcohol legal and still keep marijuana illegal. Especially when marijuana has positive affects on a person, medicinally that is. Which can induce: helping people sleep with no dependency for it once stopping, can increase appetite for HIV patients, and can relieve pain efficiently without the addiction some of our pain medications cause. Another stupid decision to keep the less strong pain medications that are addictive legal, and marijuana, a very efficient pain killer with little addiction, illegal. Any idea why half of America is blind to all of this?

@CJ--Like you, the scientists at NIDA do recognize that the THC in marijuana has effects that could potentially treat a variety of medical conditions. Along with the uses you point out-like relieving pain and increasing appetite-scientists are continuing to investigate other potential medical uses for THC. Smoking it, though, is controversial because the negative effects of marijuana smoke on the respiratory system are likely to offset potential benefits that marijuana could give to some patients. Like tobacco smoke, the smoke of marijuana consists of a toxic mixture of gases and tiny particles, many of which are known to harm the lungs. Someone who smokes marijuana regularly may have many of the same respiratory problems that tobacco smokers do, such as daily cough, more frequent upper respiratory llnesses, and a greater risk of lung infections. We still have a lot to learn about marijuana's pros and cons, but it's pretty safe to say smoking it is not a good idea if you care about your health. Thanks for your comment!

So, how about vaporizing marijuana? are there any proven health risks from that? like peer-reviewed studies? of long-term damage to brain or cognition? I say long-term, b/c obviously when someone is high, their linear cognition is affected (though they may be able to think creatively and have more associative thinking) I just haven't seen any peer-reviewed studies and I'm very very skeptical.

@Cameron - There are no long-term studies of effects of vaporizing marijuana versus smoking, because it is too new. But, there would be no reason to expect vaporizing to be any safer for brain health. Unlike tobacco, the health risks of which pertain to toxins affecting the lungs, marijuana’s risks primarily have to do with the effect of THC on the brain; with vaping as with smoking, large quantities of THC enter the brain very rapidly via the lungs.

Wait, I'm confused. I've never seen any solid evidence that THC causes any permanent or irreversible brain damage. Any changes in cognition/memory seem to be reversed with abstinence. Could you provide a peer-reviewed study showing otherwise?

The Maier et al 2012 study showed permanent loss of 8 IQ points when users began using cannabis heavily in adolescence, even if they quit as adults; if they started in adulthood, then quit, the losses were indeed reversible.   Here’s a link to an article about that study and if you scroll to the bottom you can read the study yourself.  While there continues to be much to learn about marijuana’s effects on the brain, be it through smoking or vaporizing or ingesting through food, the evidence very clearly shows that it is detrimental to the developing teen brain and our ultimate goal is to provide teens with the facts about how use of any drug, including marijuana, comes with specific health risks so that they can make the best decisions for themselves.

ello jello:) u know weed is bad and i think that that people that r addicted to durgs we should help them cause thats what im doing in my town

i think that durgs r harmful to the human body

the thng is about durgs they tend to kill the human body and they think that it is cool to do so and get high well the pepl i fill srry for the ones that r hooked on the durgs and right now i just fell reel bad about them this is mud_vanye54 saying durgs r bad!!!!!!!!!!!!!

nida, i guess you couldnt come up with a valid argument to my statement. as far as 11% who died in wrecks tested positive so? how many were high at the moment? you do know you dont stay high for 2 weeks at a time unless you smoke that much, million things to do shut it. not many pot smokers wish to argue the risks to a minimum but when someone gives biased info or lack of info that just makes it look bad its irritating. we know the dangers and want everyone else to know the risks, facts are facts and i like the good and badwhats the % of smokers who are bad addicts? (that really go through bad withdraws) i know a person that triped off of pot and his mom nearly went blind from constant use but both wished it to be legal since they knew they were a small minority. i love science and facts and would love to see the full stats that have ben collected but nida wont tell the full story. why?

peanuts kill more people than pot so argue with that!

@NIDAwriter- not being able to smoke the marijuana is a miniscule problem because there are THC pills and vaporizers both which are not smoke but produce the same affects.

Cmon all you pot smokers out there. Lets be real for a minute. You are probably still talking about all the great things you are going to do in your life, and that pot expands your mind. Ha. Its all a lie !! Dont waste your time smoking this garbage. Wake up and get help ! The biggest joke is the marijuana industry is run by criminals and you are signing their paychecks. And dont think for a minute that I dont know what I am talking about. I was an abuser for 15+ years, and found out the hard way. Dont make the same mistake.

@Weednogood It only pays criminals since everything dealing with pot is illegal, I know all about the drug industries and how the laws affect them, drugs are sold legally everyday that can cause more damage mentaly and physically than pot ever could, some with scripts and some over the counter, anything and everything can be addictive and abused so I dont want to hear that b.s. the only addiction i have is tobacco and hating rich aholes and people that do what they can to make it easier for them. I dont care about expanding my mind, ef that, I have a real bad temper that ive ben working on for 15 years and im trying to turn my back to my violent urges, im 23 and ive done good with or without, but i dont kick out the front doors of the places i work when i have a little bit of garbage in me. to be honest it works wonders for people, and ruines less lives than any single drug you can get over the counter like alcohol and tobacco.

There are too many substances that affect our life and the Marijuana is one from these.
Marijuana also known as Cannabis which is prepared from Cannabis plant intended for use as a psychoactive drug. The most common form of cannabis used as a drug is the dried herbal form.
This is nice piece of information that u gave here. I like all the points that you make in your blog. You provide an excellent overview. I feel strongly about it and I would like to read more from you. Amazing post!

Informative with a lot of misinformation should be a tag line for this article.

no calls marijuana pot...unless you're stupid. and THC is a hallucinogen and not all marijuana is spirnkled with it

@me - whaaa? THC is the active ingredient IN marijuana, not sprinkled.

Ha..Ha..Give it up folks or pot smokers.Convincing your self with drugs it's just like"chasing the wind and satisfaction"which is not happening!

lol, sprinkled. i still say legalizing would help out

Admiring the time and accomplishment you put into your blog and abundant advice you offer! I will bookmark your blog and accept my accouchement analysis up actuality often. Thumbs up!

how do you feel when ur done useing marijuan ? (withdrawl symptoms)

@hey4 When people who are addicted to marijuana try to quit, they may feel a variety of withdrawal symptoms. Along with craving, that could include feeling irritable or anxious or having trouble sleeping. That makes it hard for long-time marijuana smokers to quit, but these symptoms fade pretty quickly. The best idea is not to start, especially since the risk of addiction is pretty great (25-50%) in people who use every day, especially if they’re teens.