ADHD Comorbidities & Related Conditions

The Damaging Effects of Cannabis on the ADHD Brain

Cannabis use has grown in popularity among people with ADHD, some of whom report that marijuana helps them manage symptoms of anxiety, rejection sensitive dysphoria, and poor sleep without a prescription medication. What many teens and adults do not realize is that cannabis consumption is associated with dangerous risks — like cannabis use disorder — that disproportionately affect ADHD brains.

Cannabis and marijuana used by teens with ADHD

Cannabis is used by a startling number of people with attention deficit hyperactivity disorder (ADHD). Studies show that more than half of daily and non-daily cannabis users have ADHD1, and about one-third of adolescents with ADHD report cannabis use2. People with ADHD are also three times as likely as their neurotypical peers to have ever used marijuana.3

As with other popular substances, cannabis is commonly abused. In fact, the risk of developing cannabis use disorder (CUD), a problematic pattern of cannabis use linked to clinically significant impairment, is twice as high in people with ADHD3. Contrary to popular belief, individuals can be mentally and chemically dependent on and addicted to cannabis. Contemporary marijuana has concentrations of THC higher than historically reported, which exacerbates this. What’s more, the adverse effects of cannabis are especially amplified in people with ADHD.

What are the Negative Effects of Cannabis?

Tetrahydrocannabinol (THC), one of cannabis’ active compounds, inhibits neuronal connections and effectively slows the brain’s signaling process. THC also affects the brain’s dendrite architecture, which controls processing, learning, and the overall health of the brain. Science has not yet fully determined whether THC’s effects are reversible; some parts of the brain show healthy neuronal growth after cannabis use stops, but other parts do not.

Short-term and long-term cannabis use also impairs:

  • Motivation (hampering effect)
  • Memory, especially in people under 25, by altering the function of the hippocampus and orbitolfrontal cortex, where much of memory is processed
  • Performance on complicated task performance with many executive steps. Studies have shown, for example, that driving ability, even while not under the influence, can be impaired in regular marijuana users

Cannabis use may also lead to the following health-related impairments:

  • Chronic bronchitis
  • Chronic obstructive pulmonary disease (COPD)
  • Emphysema
  • Cannabinoid hyperemesis syndrome (characterized by severe bouts of vomiting and dehydration)
  • Elevated resting heart rate

Cannabis use may exacerbate disorders like paranoia, panic, and mood disorder. Studies have also found that increased cannabis consumption can uniquely contribute to elevating suicide risk, even when controlling for underlying mental health disorders, like mood disorder or anxiety 4 5. Individuals who begin regular cannabis use also exhibit more suicidal ideation, even when controlling for pre-existing mood disorders, studies show.6 7

What is Cannabis Use Disorder (CUD)?

Cannabis is addictive — 9 percent of people who use cannabis regularly will become dependent on it 8. This figure rises to 17 percent in those who start using cannabis in adolescence.9

CUD can develop after extended cannabis use. It is diagnosed when at least two of the following occur within a 12-month period:

  • Taking cannabis in larger amounts over longer periods of time
  • Difficulty quitting cannabis use
  • Strong desires or cravings to use cannabis
  • Lots of time spent trying to obtain, use, or recover from cannabis
  • Problems with work, school, or home because of interference from cannabis use
  • Social or interpersonal problems due to cannabis use
  • Activities given up or reduced because of cannabis use
  • Recurrent cannabis use in physically hazardous situations, such as driving
  • Physical or psychological problems caused or exacerbated by cannabis use
  • Tolerance to cannabis
  • Withdrawal from cannabis

How Does Cannabis Affect the ADHD Brain?

Cannabis use impairs areas and functions of the brain that are also uniquely impaired by ADHD.

The substance’s negative effects are most harmful to developing brains. Many studies show that usage earlier in life, particularly before the age of 25, predicts worse outcomes. One study found that heavy marijuana use in adolescence was associated with a loss of 8 IQ points, on average, in adulthood 10. Another study found that people under age 18 are four to seven more times at risk for CUD compared to adults.11

People with ADHD, whose brain development is delayed by slowly maturing frontal lobes, are thus more vulnerable to cannabis’ effects on neuronal connections. Some of these impairments may be irreversible.

Cannabis can also interact significantly with some ADHD medications. Research studies have shown that methylphenidate (Ritalin, Concerta) reacts significantly with the substance, and can cause increased strain on the heart.12

Other studies show that the use of cannabis can decrease the effect of a stimulant medication13. An individual trying to treat their ADHD with stimulants is actually placing themselves at a disadvantage, since the cannabis is impacting them negatively and making the medication less effective.

The increased risk of suicide associated with cannabis use further complicates marijuana among individuals with ADHD, who already face an elevated risk for suicide compared to neurotypical individuals 14.

What Draws People with ADHD to Cannabis?

Cannabis activates the brain’s reward system, and releases dopamine at levels higher than typically observed. In low-dopamine ADHD brains, THC thus can be very rewarding.

Many people with ADHD also claim that cannabis helps them focus, sleep, or seemingly slow the pace of their thoughts. One analysis of internet threads found that 25 percent of relevant posts described cannabis as therapeutic for ADHD, while 5 percent indicated that it is both therapeutic and harmful 15. Despite some users reporting short-term improvement in symptoms, there is currently no evidence that suggests cannabis is medically or psychologically helpful for managing ADHD in the long-term.

Cannabis’ increased availability and legalization have increased accessibility; many cannabis products are falsely marketed as medicinal for ADHD.

Also contributing to an increased likelihood of cannabis use and CUD among individuals with ADHD is the prevalence of low self-esteem, sleep problems, poor impulse control, and sensation-seeking tendencies in this population.

How is Cannabis Use Disorder Treated in People with ADHD?

There is no approved medication to treat CUD — treatment generally means teaching patients strategies to maintain sobriety. Treatment can include talk therapies, like cognitive behavioral therapy (CBT) and dialectical behavior therapy (DBT), and participating in support groups like Marijuana Anonymous.

One small but insightful study looking at motivations to quit cannabis use in a group of adults with ADHD found that saving money was a major contributing factor 16. The same study found that the most common strategy for maintaining abstinence was breaking social connections with people who smoke marijuana.

Treating and targeting ADHD itself in a patient that has CUD is also essential. Stimulant medication can be implemented as part of ADHD treatment, and it is not considered a violation of sobriety.

How Should a Parent Help a Teen with ADHD Who Is Using Cannabis?

It’s normal for parents to experience a range of emotions after discovering that their child is using cannabis. The initial gut reaction or emotion is understandably anger and disappointment, but it’s best to release these feelings prior to engaging in conversation. Any dialogue with teens must be done in a controlled, calm way — teens will not listen to parents who are yelling and blurting out things they will later regret.

Seeking consultation with a doctor, pediatrician, or therapist who has experience in substance abuse can help, especially for parents who are struggling with their owns feelings and reactions toward their child.

The next step is for parents to educate themselves on cannabis and how it can be appealing. Parents should try to proactively see what their child might be experiencing, and why they might have turned to the substance. When the conversation does start, parents should work deliberately not to shame their child, and instead focus on understanding their child’s experience on cannabis.

Parents should calmly ask questions like:

  • “I found this and I’m concerned, but I’d like to know what the appeal of this is for you?”
  • “What does this do for you?”
  • “How did you feel the very first time that you did this?”

While parents are encouraged to have calm and thoughtful conversations with their teen, they should also set boundaries and consequences for substance use to remind their child that it is not acceptable. Without shaming, parents must establish rules that discourage substance use, especially in the household.

Many parents will say that they would rather have their child smoke in the house than outside with others. But this mentality doesn’t stop teens from smoking or using anywhere else. Instead, allowing at-home use communicates a sense of permission associated with substance use.

If teens say they are simply experimenting, they should know that experimentation can quickly turn into something more dangerous. Parents should inform them that teens with ADHD are at higher risk for addiction. Teens should also be aware, if they aren’t by this point, of any family history of addiction, which also has a genetic component.

Placing limits on smoking can create some backlash. Teens and young adult may be so gripped by the substance they they are willing to lie about using it to parents. Parents should approach their child if they suspect they are using, even after rules are in place, but should keep in mind that this substance, like any, can have people not always be truthful. That’s very different from thinking that their child can’t be trusted and is a liar.

Children should be reminded that they are loved and that their health is most important. Smoking marijuana doesn’t mean that parents have failed or that they’ve done a bad job with their children. There’s a terrible stigma on addiction surrounding character and morality — it’s important to remember that teens aren’t using drugs because they are bad people. Very, very good people are addicted to substances or experiment with them.

The information in this article is based on Dr. Roberto Olivardia’s two-part Marijuana and the ADHD Brain webinar series. The first part, “Marijuana and the ADHD Brain: How to Identify and Treat Cannabis Use Disorder in Teens and Young Adults” was broadcast live on February 26, 2020. “Marijuana and the ADHD Brain, Part 2” was broadcast live on March 26, 2020.


1 Loflin, M. et. al. (2014) Subtypes of Attention Deficit-Hyperactivity Disorder (ADHD) and Cannabis Use, Substance Use & Misuse, 49:4, 427-434, DOI: 10.3109/10826084.2013.841251

2 Molina, B. S. et. al. (2013). Adolescent substance use in the multimodal treatment study of attention-deficit/hyperactivity disorder (ADHD) (MTA) as a function of childhood ADHD, random assignment to childhood treatments, and subsequent medication. Journal of the American Academy of Child and Adolescent Psychiatry, 52(3), 250–263.

3 Lee, S. et. al. (2011). Prospective association of childhood attention-deficit/hyperactivity disorder (ADHD) and substance use and abuse/dependence: a meta-analytic review. Clinical psychology review, 31(3), 328–341.

4 W. Pedersen, “Does cannabis use lead to mood disorder and suicidal behaviors? A population-based longitudinal study,” Acta Psychiatrica Scandinavica, vol. 118, no. 5, pp. 395–403, 2008.

5 Schmidt, K., Tseng, I., Phan, A., Fong, T., & Tsuang, J. (2020, Feb.). A Systematic Review: Adolescent Cannabis Use and Suicide. Addictive Disorders & Their Treatment. doi: 10.1097/ADT.0000000000000196

6 H. Chabrol, J. D. Mabila, and E. Chauchard, “Influence of cannabis use on suicidal ideations among 491 high-school students,” Encephale, vol. 34, no. 3, pp. 270–273, 2008. Doi : 10.1016/j.encep.2007.04.002

7 Raja, M., & Azzoni, A. (2009). Suicidal ideation induced by episodic cannabis use. Case reports in medicine, 2009, 321456.

8 Lopez-Quintero, C., et. al. (2011). Probability and predictors of transition from first use to dependence on nicotine, alcohol, cannabis, and cocaine: results of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). Drug and alcohol dependence, 115(1-2), 120–130.

9 Volkow, N. D. et. al. (2014). Adverse health effects of marijuana use. The New England journal of medicine, 370(23), 2219–2227.

10 Meier, M, et. al. (2012). Cannabis use and neuropsychological decline. Proceedings of the National Academy of Sciences. 109 (40) E2657-E2664; DOI: 10.1073/pnas.1206820109

11 Winters, K. C., & Lee, C. Y. (2008). Likelihood of developing an alcohol and cannabis use disorder during youth: association with recent use and age. Drug and alcohol dependence, 92(1-3), 239–247.

12 Kollins, S. et. al. (2015, Jan). An exploratory study of the combined effects of orally administered methylphenidate and delta-9-tetrahydrocannabinol (THC) on cardiovascular function, subjective effects, and performance in healthy adults. Journal of substance abuse treatment, 48(1), 96-103.

13 Volkow, N. D., Wang, G. J., Telang, F., Fowler, J. S., Alexoff, D., Logan, J., Jayne, M., Wong, C., & Tomasi, D. (2014). Decreased dopamine brain reactivity in marijuana abusers is associated with negative emotionality and addiction severity. Proceedings of the National Academy of Sciences of the United States of America, 111(30), E3149–E3156.

14 Balazs, J., & Kereszteny, A. (2017). Attention-deficit/hyperactivity disorder and suicide: A systematic review. World journal of psychiatry, 7(1), 44–59.

15 Mitchell, J. T. et. al. (2016). “I Use Weed for My ADHD”: A Qualitative Analysis of Online Forum Discussions on Cannabis Use and ADHD. PloS one, 11(5), e0156614.

16 Chauchard, E. et. al. (2018). Cannabis Withdrawal in Adults With Attention-Deficit/Hyperactivity Disorder. Prim Care Companion CNS Disord. 20(1). pii: 17m02203. doi: 10.4088/PCC.17m02203.

7 Comments & Reviews

  1. I’m tired of just about everyone acting like marijuana is harmless.

    Reading this article, I said yes to the following with regards to my fiance.
    Difficulty quitting cannabis use
    Strong desires or cravings to use cannabis
    Physical or psychological problems caused or exacerbated by cannabis use
    Tolerance to cannabis
    Withdrawal from cannabis

    He had a heart attack in early February, and they placed two stents. One artery was 90% blocked, the other was 100% blocked.
    The cardiologist stated he was not to return to smoking, as it could contribute to his heart condition. Everyone thinks he is smoking it because of his back pain, but that is only part of the picture. He is an addict of another substance, and I won’t get into it here. The cardiologist and his family seem to think that him using edibles will solve that issue. It would, if he was just treating the pain. I think he uses it to de-stress and he likes being high/stoned. I don’t like the way he acts when he is on it. He does not remember his behavior when he is high. I had a surgery last summer, and was told I needed a driver, because I would still be under the influence of anesthesia. My fiance drove me home, but while I was still in recovery, he decided to step out into the parking garage and smoke it in his car. When I smelled the stank on him, I was pissed.
    All I can do is hope things will get better. I love him, and he treats me well. I hope his smoking won’t lead to another heart attack. You would think the heart attack would scare him enough that he wouldn’t want to risk it, but given that he is an addict, the pull of the substance is greater.

  2. I feel a lot of this article is fear-mongering click bait.

    I do think there are dangers of marijuana use, and sure, anything can be addictive. But I also think that there are a lot of positive outcomes as well. This article also seems to focus mostly on tweens, teens and young adults and consumption by smoking. There is no mention of microdosing, sublinguals, low dose tablets and topical uses. Nor does it talk about safety in moderation, use in conjunction with other types of help (ie: cognitive behavioral therapy).

  3. Wow really outdated and paranoid article. It’s shocking how NOT ONCE by anyone even in the comments mentioned the default assumption was that everyone using cannibinoids are smoking it? You ignorant dummies, the reason for those associations is that burning a substance and then inhaling that burning substance brings carcinogens directly into your body. Yes, there is lost cognitive function with abuse, mainly through dendritic loss and the COX2 signalling pathway but thats the case with may psychiatric meds anyway.

  4. “While parents are encouraged to have calm and thoughtful conversations with their teen, they should also set boundaries and consequences for substance use to remind their child that it is not acceptable.”

    To me, this quote almost completely destroys the validity of this article. How is it possible to have a thoughtful conversation with someone while holding a predetermined conclusion? As a regular cannabis user and teen with ADHD, I could always sense when my parents would discuss my behavior as if it was an open discussion, while clearly angling for a single outcome from it – and it would always lead to their frustration (instead of open-mindedness) when I brought up points that contradicted their pre-conceived view.

    This isn’t to say my cannabis use hasn’t caused me problems in the past, but rather that I believe the approaches and viewpoints to dealing with it shared in this article are flawed. The article defines a loose and open-to-interpretation definition of Cannabis Use Disorder, and then proceeds to imply all levels of use fall into this category. Imagine an article written about Alcohol that implied any regular use of it qualified you as an alcoholic! The truth is, cannabis, like alcohol, caffeine, adderall etc. can bring benefits in MODERATION. I self-medicate many of my ADHD symptoms with it, including as a motivating reward for completing work, as a dopamine boost to push myself to complete chores and, probably most beneficially, to provide mental relief from the stresses of day-to-day life a person with ADHD experiences. The risk/reward ratio has always been positive for me, which may be difficult for others to understand since the rewards of cannabis use are experienced personally.

    MY PROBLEM WITH THIS ARITCLES INTERPRETATION OF CUD: If you smoke enough weed to increase your tolerance to it, you are also violating taking cannabis in larger amounts over longer periods of time, meaning you fit enough of the criteria to have the disorder, even though you may be experiencing no actual ill effects! Nearly everyone I know has experienced varying levels of tolerance and therefore use with other substances (alcohol, caffeine), but very few of them have had actual problems with those substances. Also, there is no mention of tolerance breaks as an effective treatment for CUD, leading me to believe the article is biased by the incorrect view that Cannabis is inherently harmful, and no use of it should be tolerated.

  5. This is fear-mongering clickbait.

    Marijuana has been instrumental in helping those with mental illness- depression, and anxiety to name two that are often associated with ADHD. There are multiple tools and ways for one to ingest cannabis, yet smoking is the single method mentioned here.

    It seems the author of this article has preconceived notions on marijuana and marijuana use and all of their research was based on finding information that supported those beliefs.

    This is an outdated view. Alcohol and prescription drugs are far more addictive and dangerous than cannabis.

  6. What a nonsense. I dont only have adhd but also fms, spd, eds, sjogrens, pelvic disability, graves disease, severe depression and ptsd and autism. I use thc oil or cbn against pain, and other stuff. Smoking cannabis is not done. Most people i know who dont use oil, vape. Tobacco kills and is more addictive. My dog with cancer is on pure cbd paste and i rub her tumor with weed creme. Your article is so off. Its 2021, read up on stuff.

  7. Did BIG PHARMA sponsor this? Such much fear mongering. My doctor already recommended the use of cannabis for the treatment of anxiety and ADHD years ago. The author here has a Ph.D, not a Pharm-D or an M.D. degree. So, I’m going to go with the professional opinion of someone who is certified by the board of medicine to give me recommendations. My wife is also a doctor, and she agrees with my physician on this. Gotta love Ph.D’s that pretend they have the background, education, and experience to make medical recommendations. Go to med school, graduate, and then come talk to us.

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