Cannabis and the Teenage Brain: Why Adolescents Must Avoid Marijuana

on Apr 17, 2023| Modified on Apr 17, 2023

Teenagers often face a myriad of challenges as they navigate the transition from childhood to adulthood. Among these challenges is the increasing prevalence of cannabis use, fueled by its growing popularity and changing legal status. 7

While cannabis has its proponents and is touted for potential medical benefits, its effects on the teenage brain warrant careful consideration. 1 In this article, we will explore how marijuana affects the developing brain and why it should be avoided by adolescents.

The Teenage Brain: A Work in Progress

During adolescence, the brain undergoes significant development and remodeling. This period is crucial for forming neural networks that will support cognitive functions, memory, and decision-making throughout adulthood.6 The endocannabinoid system, consisting of endocannabinoids, cannabinoid receptors (CBRs), and enzymes, plays a vital role in this process. 1

When teenagers use marijuana, the THC (tetrahydrocannabinol) present in cannabis interacts with the endocannabinoid system. This interaction can alter normal brain development, leading to potentially long-lasting and detrimental consequences. 1

The Effects of Marijuana on the Developing Adolescent Brain

1. Impaired Cognitive Functions and Memory

Marajuana use during adolescence has been linked to impaired cognitive functions and memory. THC disrupts the normal communication between neurons and CBRs in the brain, affecting the brain's ability to process information, form new memories, and learn. This interference can have a lasting impact on academic performance and overall intellectual growth. 4

2. Altered Brain Structure

Research has found that chronic marajuana use during adolescence can lead to structural changes in the brain. These alterations can affect areas responsible for decision-making, impulse control, and emotional regulation. Such changes may contribute to the development of mental health issues and increase the risk of addiction. 6

3. Increased Risk of Mental Illness

Studies have shown that cannabis use during adolescence increases the risk of developing mental illnesses such as schizophrenia, anxiety, and depression. The changes in the endocannabinoid system observed in people with schizophrenia suggest that marijuana use may exacerbate or trigger the onset of these disorders, particularly in individuals with a genetic predisposition. 5

4. Impact on School Performance and Social Functioning

Teenage marijuana use can negatively affect school performance and social functioning. The impaired cognitive abilities, memory, and attention span caused by cannabis use can lead to poor academic performance and decreased motivation.4  The impaired cognitive abilities, memory, and attention span caused by cannabis use can lead to poor academic performance and decreased motivation. Additionally, teenagers under the influence of marijuana may struggle with interpersonal relationships and experience social isolation. 7

Why Teenagers Should Avoid Cannabis

Considering the potentially lasting impact of marijuana on the developing brain, it is crucial for teenagers to avoid its use. Parents, educators, and healthcare professionals should collaborate to educate adolescents about the risks associated with teenage marijuana use and support those struggling with substance abuse. 7

In conclusion, while cannabis may offer some benefits for specific medical conditions in adults, its effects on the teenage brain are concerning. As the brain develops during adolescence, it is particularly vulnerable to the negative consequences of marijuana use[1]. By avoiding marijuana, teenagers can protect their cognitive abilities, mental health, and future success.


  1. Jacobus, J., & Tapert, S. F. (2014). Effects of cannabis on the adolescent brain. Current Pharmaceutical Design, 20(13), 2186-2193. Link
  2. Volkow, N. D., Baler, R. D., Compton, W. M., & Weiss, S. R. (2014). Adverse health effects of marijuana use. New England Journal of Medicine, 370(23), 2219-2227. Link
  3. Giedd, J. N. (2004). Structural magnetic resonance imaging of the adolescent brain. Annals of the New York Academy of Sciences, 1021(1), 77-85. Link
  4. Meier, M. H., Caspi, A., Ambler, A., Harrington, H., Houts, R., Keefe, R. S., ... & Moffitt, T. E. (2012). Persistent cannabis users show neuropsychological decline from childhood to midlife. Proceedings of the National Academy of Sciences, 109(40), E2657-E2664. Link
  5. Large, M., Sharma, S., Compton, M. T., Slade, T., & Nielssen, O. (2011). Cannabis use and earlier onset of psychosis: a systematic meta-analysis. Archives of General Psychiatry, 68(6), 555-561. Link
  6. Lubman, D. I., Cheetham, A., & Yücel, M. (2015). Cannabis and adolescent brain development. Pharmacology & Therapeutics, 148, 1-16. Link
  7. National Institute on Drug Abuse. (2019). Marijuana. Link

Related Links:

The Power of Medical Cannabis: Healing Properties and Benefits
Understanding Cannabis Addiction: Natural Remedies for Treatment

Marijuana and Mental Health Issues

Posted by Elaine (Va) on 11/26/2013

I, too, have family members who felt 'it's only pot' and now have mental health issues. From the pot? I don't know, but the fact is that they have an illness now that non-pot smoking members of a very large family do not have. There may be a genetic component, as this is a large family with many double first cousins (sibling marry siblings, then their children marry, etc). Recipe for genetic upset, I know. As for the pot, I think it wise to not take it at least until the body is fully mature--why risk damage to a developing body with a non-essential item? I'm okay with my elderly mother using it for glaucoma or pain relief; she no longer drives and if it makes her life easier I say okay. That leaves the young-adult to retirement age group. I am not okay with getting wasted, and any impairment at all is not okay to be out driving, etc. The impaired individual rarely thinks he is impaired, and there's no test. Also, younger people help themselves to their parents tobacco and alcohol, so you can't control it in the home. This is a problem. Bottom line, we should take good care of ourselves and this means probably no mind-altering substances.

Replied by Timh
(Ky, Usa)
2063 posts

To not distinguish chronic or excessive Pot use in youth from occasional or moderate is an error of thinking. Bad premise and procedure always end w/ bad conclusions and results.

Marijuana and Schizophrenia

Posted by Karen (Santa Barbara, California) on 11/26/2013

I was very glad to receive your latest article on marijuana and the brain. I have a story to share with you. I had a brilliant friend who started with pot in the 1960s. Like many others during that time, he also dropped acid. As he aged, he became extremely delusional and thought various groups were after him. I believe now he had undiagnosed and untreated schizophrenia. He self medicated with marijuana because it was the only thing that made him feel better. However, as one of his closest friends who saw him frequently, I saw that the marijuana made his delusions much worse. The more delusional he became, the more pot he smoked. It was a vicious cycle. He was so miserable. No one in his family or circle of friends could get him the help he needed although we tried and tried. One day he took his own life to end his misery. It was very sad.

One day, a year or two before his death, I tried a small amount of his "medication", pot he said was from Thailand, only the 2nd time in my life to do so. It made me so extremely paranoid for the few hours it was in my system, I almost went to the ER. It makes me shudder to think how many teenagers are smoking it daily thinking it's harmless. Until you've watched a loved one falling apart before your very eyes, you don't really know.

Marijuana and Schizophrenia
Posted by Candance (Nebraska) on 11/25/2013

Interesting article, I enjoyed reading it as I have heard many times that the use of cannabis could have an effect on the brain with teenagers but never had anyone explained in detail how it could effect the brain.

My son was diagnosed with Schizoeffective when he was 20 years old. The illness runs in the family as his father had it also. We have learned to control it via a combination of diet, supplements, meds AND cannabis.

Without all three he quickly goes downhill. It has taken us 10 years to get to where we are now. I don't know about the teenage use and the connection with the illness I just know it runs in the family. But I do know without it now he has issues. We have had him tested several times for temporal lobe epilepsy as it can have the same symptoms as schizophrenia and it has been proven cannabis use can help improve it but so far they have not been able to find any signs of it with my son.

Whether it was genetics or cannabis use that caused this illness for my son I don't know but I do know now without it his brain does not function normally.

I would strongly suggest that if anyone has a teenager and if there is any history of mental illness in your family, share this information with your teenager. Mental illness is very devastating and robs you of your future.

Marijuana and the Teenage Brain

Posted by Kevin (Victoria, Australia) on 11/27/2013

WOW, you guys just brought in a whole lot of controversy as always. It doesn't appear that this is going to change for obvious controlling governmental reasons. For the main part, marijuana, pot whatever you want to call it, is not a drug. 10-33 times stronger, not likely or one would find themselves overdosing quite easily and feel very uncomfortable.

As far as teens smoking it and having the growth of their minds altered, well that is an ongoing study. Some people I have witnessed benefit from smoking weed, some get slower and lethargic and lazy. It all depends on the individual, however, like most nonsensical scientific diatribe, we all seem to get lumped into the ONE category.

People are all different in the way the makeup of their bodies respond to marijuana. I, personally, do not like the initial feeling of getting high, but I feel great shortly afterwards. Some people never know when to stop or moderate with marijuana use, thus abusing something that could be of benefit to them.

Once again, I feel this article has been manipulated by the big pharmaceutical industries and besides why are the pharma companies trying to create a synthetic form of marijuana and market it. Is it because there are more benefits to the use of MJ than not? If they can market a patent on this plant then I guess there are billions of dollars to be had now isn't there.

All this rhetoric about motor skills being slowed down and so forth. I have witnessed people becoming heightened in their awareness, so once again the individual has been wrongly categorized by pseudo science. It all depends on the dose, besides shouldn't we be concerned of the millions of people driving in their vehicles everyday that have just taken their pharma medications and are completely impaired at the wheel of their 4000lb vehicle??!!! Yes, really now, wake up. More people are impaired by prescription drugs than alcohol and marijuana combined. But I guess most people would not comprehend this primarily because most people live in a comatose-brainwashed state of mind since the introduction of chemtrail pollutants and microwave radiation and whatever else the controlling forces of this messed up planet would throw at us.

Also, when you grow marijuana under synthetic light and unnatural soil and with chemical bug sprays, it is not the natural plant anymore and yes, you may call it a drug since the original intent of the plant has been altered. So who is to blame for this then? The ones who want to control MJ!! If it was a free plant, and notice I did not say LEGALIZED!! , all would be well on this planet. Man has not learned to leave things alone, especially the creators laws. Until then, my name is Kevin.

Replied by Gavin
(Northland, New Zealand)

The main thing to remember is that the young brain has enough troubles programing itself during the post puberty period. Mary Jane and any other psychotropic stuff, legal and illegal should be avoided until maturity. Unfortunately the young brain only gets one chance at this, common sense suggests that it's best to stay clear. If taken as an adult the mature human brain has set itself a fall back position. So occasional use doesn't seem to be a problem. Same goes with alcohol.

Replied by Timh
(Ky, Usa)
2063 posts

Back in the day when being "high" in the wrong place at the wrong time needed some assistance. I would pop a daily vitamin, w/ a cup of Java, fallowed by 500mg vit-c and sober up enough to get thru it. Also, as an aid to brain health during any kind of stress ---Lecithin. There are several manufacturers marketing "triple strength lecithin" which would certainly provide all day support and more. The Choline in lecithin is both a fat burner and a detoxifyer; so the choline would certainly be indicated for the lipid cannabinoids. Along w/ other nutrients like the daily multivitamin, will support a cleaner "high" by reducing the side affects like paranoia and oversensitivity.


Posted by Susan (Los Angeles, Ca) on 02/21/2014

On the subject of Marajuana and the Brain, Dr. Daniel Amen's team put out an interview on the subject:

and SPECT scan images of drugs like marijuana on the brain:

Slowed Brain Function

Posted by Gina (Texas) on 11/25/2013

hmmm. my two cents: in my 40 years of marijuana experience I know personally only two people whose marijuana use slowed their brain function when they weren't using. both are male, both started smoking shortly after they reached puberty. one was in the 70s, so he wasn't smoking strong weed. the other has been since 2000, so he was. the first guy wasn't that bright to begin with, the second was. he is still smarter than the average bear, but not near as quick as before. I have heard from other people of men who've been affected that way, but never heard of it happening to a woman.

Replied by Jutza98
(Fort Collins, Co)

Nice article!! I am sick and tired of people defending how a person is affected by pot. The idea that pot is harmless is just wrong, it is not harmless, it is a mind altering drug, plain and simple!!!

People who smoke pot and drive are no different than those who drink and drive, or take prescription medication and drive - all have impaired thinking and "slowed brain functioning"!!

Anyone who believes the fantasy that pot is harmless is living in their own fantasy world.

Perhaps people need to work as a death investigator and see what the "harmless" pot does to people. Driving while only smoking pot has killed the driver as well as those innocent other people either in the same vehicle as the "slowed brain functioning" pot smoker, or an innocent sober driver in another vehicle. Pot is a depressant and I cannot count the number of suicides that have occurred with the only thing in the person's system was THC!!!

I don't care what another person does to their own minds and bodies, however, let's quit the pretending that pot is harmless and cures so many ailments. If they want to promote it as a medicine, then regulate it as such.

I personally have seen way too many people affected by pot. Just as some people are more hyper on alcohol, so are some people on pot. Another lie is that all people who ingest pot are mellow. That is as wrong as saying all people who drink are hyper and crazy.

It always amazes me how people also claim that pot is not addicting. I want to know why then do they spend so much time getting their next fix of pot? If they spent as much time trying to get a job as they do to score some weed they might just lead a happier life and not be so depressed!!

I also personally know several individuals who smoked/ingested pot for many years only to be later diagnosed with BiPolar Disorders. Again, like the issues explained in this article continual use of marijuana might just get the user a serious mental disorder by altering their brain functions with what they think is "harmless"!!

Replied by Prioris

The number one problem with drugs is making them illegal. This allows the state to artificially manufacture crime and help build up the police state out of thin air. Many people will rail against drugs while turning a blind eye to state involvement on all levels.

Too much water can be damaging to ones health. What the study neglects to do is determine how much is too much. There is risk in almost everything. As far as marijuana use, we're talking about a broad spectrum of use by people.

When we're talking about addiction, different substances have different addiction profiles. Someone can be addicted to heroin or smoke cigarettes but still lead a normal life.

btw I don't use marijuana.