Marijuana myths abound – weed is safe, weed calms anxiety, weed does not hurt anyone. These myths are wrong!

Smoking cannabis has complications for some.

Check out the two stories of college cords who developed cannabis use complications – Cannabis Use Disorder and Amotivational Syndrome.

These are two of the most common complications of chronic marijuana (cannabis) use among teens and young adults – Cannabis Use disorder (CUD) and Cannabis Hyperemesis Syndrome (CHS), each of which occurs in about 10 percent of regular cannabis users.

Comparable conditions that occur in ~10% of people.

Below are comparisons to other common conditions that support our framing CUD and CHS not as rare disorders, but as important, under-recognized public health concerns, especially in high-use populations like adolescents or daily cannabis users.

• ADHD in children ~10% (most common neurodevelopmental diagnosis)
• Asthma in children & adults ~7–10% (higher in urban/low-income settings)
• Anxiety disorders in teens ~9% (higher since 2020 and the pandemic)
• Type 2 Diabetes in adults ~11% (age 20+) (higher in older adults)
• Migraine in adults ~9–10% (higher in women)
• Chronic Kidney Disease (CKD) ~15% (mostly mild/moderate) Stage 3+ in ~6%
• Major Depressive Disorder (MDD) in adults ~8–10% (higher in women)
• Generalized Anxiety Disorder (GAD) ~7–10% lifetime (may co-occur with depression)
• Substance Use Disorders (non-cannabis) ~10.5% (alcohol, opioids, stimulants)
• ADHD in adults ~ 8–10% (more common in males)
• PTSD ~6–10% over lifetime (higher in women, veterans, trauma survivors)

graphs showing support for legalization of marijuana

Recently, there has been a rise in public support for marijuana (cannabis) use. As more states have legalized medical and recreational marijuana since 2012, national attitudes have become more favorable.

According to a 2025 Pew Research Center survey, about 54% of U.S. adults support legalizing marijuana for both medical and recreational use. Thirty-three percent support it for medical use only, and 12% oppose legalization entirely

Support for legalization varies by age group: Pew found that for those under 30 years old, ~65% favor both medical & recreational legalization, for those aged 65 to 74, only ~49% support both uses, and among elders over 75 years, only 31% support both. Older adults more often favor medical use only or oppose legalization.

Younger adults are consistently the most supportive of legalization. Gallup examined these preferences in 2020 and found that among 18 to 29-year-olds, ~79% are in favor of legalization. Those 30 to 49 years felt similarly, with ~75% in favor. The support for legalization fell off at ages 50 and above to ~55 to 60%.

In addition, our current partisan divide also effects support for marijuana legalization. Democrats overwhelmingly support legalizing marijuana, Independents lean strongly in favor, and Republicans remain narrowly divided.

Discrepancies in the public perception of the effects of cannabis use (marijuana)

However, there exist several discrepancies in the public perception of the effects of marijuana. In a July 2024 Gallup poll, young adults (18 to 34) generally perceived marijuana as positive for users (though positivity has declined since 2022).

By contrast, adults aged 55+ saw cannabis as negative for users. Across all age groups, fewer than half now believe legalization has a positive impact on society as a whole.

Not surprising is the fact that forty-nine percent of adults report having tried marijuana at least once, but only 12% use it regularly (about once per month or more). Younger adults (under 50) are roughly twice as likely to be regular cannabis users compared to those aged 65+ (12% vs. 6%).

Younger groups view marijuana more positively, both in terms of individual effects and general acceptability, compared to older generations. Usage patterns follow similar trends with younger adults being more likely to be regular users.

It’s Not as Harmless as You Think: What Parents Need to Know About Teen Marijuana Use

Cannabis Use Disorder

Here’s the catch – epidemiologic research suggests that about 1 in 5 (20%) of regular, recreational marijuana users will develop Cannabis Use Disorder (CUD) at some point. That risk increases significantly with frequent or early use, high potency of THC, and early age at initiation (under 18 years old). Other risk factors for developing CUD include current mental health disorders (e.g., depression, anxiety), genetic or family history of substance use disorder, and lower socioeconomic status or school disengagement (for adolescents).

How likely are you or your teen to develop CUD? (these data are shocking).

• Among lifetime users of cannabis, ~9% will ultimately develop CUD.
• Among regular/recreational users, about ~20% (or 1 in 5) will progress to CUD.
• Among daily users this prevalence skyrockets to 25 to 50%.
• Among adolescents with early onset, 17 to 25% of moderate users will progress to CUD.  That rate increases to 50% for adolescents who are daily users. 

While most recreational users do not become dependent, daily users and teens face the highest risk. The overall lifetime risk of CUD among marijuana users is about 9–20%, but up to 50% for daily adolescent users.

young adult smokin marijuana (cannabis)

The key symptoms of Cannabis Use Disorder include:

• craving and strong urges to use,
• unsuccessful efforts to cut down,
• using more than intended,
• neglecting responsibilities,
• withdrawal symptoms (irritability, sleep issues, loss of appetite),
• continued use despite physical or psychological harm.

Check here for a checklist of symptoms for CUD.

Amotivational Syndrome

Amotivational Syndrome is not a formally recognized medical diagnosis, but it is a well-described behavioral phenomenon observed in chronic cannabis users, particularly those with Cannabis Use Disorder (CUD). The syndrome refers to a persistent lack of motivation to engage in goal-directed activities, especially in academic, occupational, or personal domains. My story of about my younger daughter’s college crash exemplifies this condition. Link

Telltale symptoms of amotivational syndrome include:

• apathy,
• reduced initiative,
• decreased productivity (poor performance at school, work, or home),
• blunted affect (a limited emotional expression or emotional flatness),
• social withdrawal, low energy and fatigue,
• poor concentration (difficulty focusing or sustaining attention, even on simple tasks),
• lack of long-term planning and disinterest in setting or achieving future goals.

Check here for a checklist of signs of Amotivational Syndrome.

Cannabis Hyperemesis Syndrome

Cannabis Hyperemesis Syndrome (CHS) is a relatively rare but increasingly recognized condition that affects some long-term, frequent cannabis users. Estimates vary, but here’s the current understanding based on recent studies and medical reviews:

The prevalence Cannabis Hyperemesis Syndrome (CHS) among frequent cannabis users is ~6% to 10%. There are emergency department data indicating that CHS cases represent a growing proportion (estimated 10–30%) of unexplained vomiting visits among young adults in states where cannabis is legal. Prevalence of CHS is hard to pin down due to underdiagnosis, misdiagnosis (as cyclic vomiting syndrome or gastroenteritis), and patient reluctance to disclose cannabis use.

CHS was first described in 2004. The symptoms of CHS in chronic cannabis users aged 18 to 35 years old are

• cyclical nausea and vomiting, and abdominal pain.
• gradual onset, and vomiting episodes worsen over time.
• temporary relief is described from hot showers or baths.
• in the emergency department, treatment involves IV fluids and antiemetics.

CHS occurs mostly in daily users for more than one year, and usually those using high potency THC >10%.

Symptoms of CHS often resolve completely when cannabis use stops. Cessation is the only known cure.

How parents can approach the conversation with their teen or young adult who uses marijuana.

Approaching a teen or young adult who uses marijuana can be challenging—but with the right tone and strategy, it can be a powerful opportunity to open communication, express concern, and guide healthier decision-making.

Prepare yourself and stay calm. Avoid reacting emotionally or with immediate punishment. Your tone matters more than your facts at first. (You have the facts you need in this article.)

• Start the conversation during a calm, private moment – not when you’re angry or during a conflict. Begin with open-ended, nonjudgmental questions:
• “Can I ask you something? How does marijuana fit into your life right now.”
• “How do you feel when you use it? What do you like about it?”
• “Have you ever thought about what it might be doing to your energy or your mood?”
• Express concern, but not control, and frame your concern as care, not criticism.
• “I’m not mad at you—I’m worried about you.”
• “I love you and I see some things changing, like your motivation and mood, and I wonder if marijuana is part of that.”
• Try to avoid accusations (“You’re throwing your life away!”) and absolutes (“You always…” or “You never…”). Please try to avoid shame (“You’re lazy because of weed.”)
• Use “I” statements: “I’ve noticed…”, “I feel worried when…” and try to stay curious, not confrontational.
• If they’re open, share relevant, science-based facts. 1)The adolescent brain is still developing until ~25 years-old. 2) Daily or high potency use increases risk for anxiety, depression, and Cannabis Use Disorder. 3) Marijuana can affect motivation, attention, sleep, and academic or work performance. 4) CHS (Cannabis Hyperemesis Syndrome) is a real and rising concern.
• Try to listen more than you talk. Teens are more likely to reflect on their behavior if they feel heard. Validate what they’re experiencing: “I get that it helps you relax” or “You’re not the only one feeling anxious.”
• Offer support. If your teen seems open to change, then help them identify goals: “What do you want your summer/job/school year to look like?” Maybe encourage a trial break from cannabis: “What if you tried 30 days off and see how you feel?”
• Suggest talking to a counselor or doctor—especially if there are signs of anxiety, depression, or dependency. You should seek professional guidance if:
• They are daily users or show signs of addiction (withdrawal, defensiveness, neglecting responsibilities).
• There are other mental health concerns or worsening school/work performance.
• They resist all feedback and your relationship becomes volatile.

References

Hasin, D. S., Sarvet, A. L., Cerdá, M., Keyes, K. M., Stohl, M., Galea, S., & Wall, M. M. (2017). US adult illicit cannabis use, cannabis use disorder, and medical marijuana laws: 1991–1992 to 2012–2013. JAMA Psychiatry, 74(6), 579–588. https://doi.org/10.1001/jamapsychiatry.2017.0724

Volkow, N. D., Han, B., Compton, W. M., & Blanco, C. (2016). Marijuana use and use disorders in adults in the USA, 2002–14: Analysis of annual cross-sectional surveys. The Lancet Psychiatry, 3(10), 954–960. https://doi.org/10.1016/S2215-0366(16)30208-5

Patnode, C. D., Perdue, L. A., Rushkin, M., O’Connor, E. A., Bean, S. I., Guirguis‑Blake, J. M., & Whitlock, E. P. (2020). Screening for drug use in primary care in adolescents and adults, including pregnant women: An updated systematic review for the U.S. Preventive Services Task Force (Evidence Synthesis No. 186). JAMA, 323(22), 2310–2328. https://doi.org/10.1001/jama.2020.1432

Sorensen, C. J., DeSanto, K., Borgelt, L., Phillips, K. T., & Monte, A. A. (2017). Cannabinoid Hyperemesis Syndrome: Diagnosis, Pathophysiology, and Treatment—A Systematic Review. Journal of Medical Toxicology, 13, 71–87. https://doi.org/10.1007/s13181-016-0595-z

Monte, A. A., Shelton, S. K., Mills, E., Saben, J., Hopkinson, A., Sonn, B., Devivo, M., & Heard, K. (2019). Acute Illness Associated With Cannabis Use, by Route of Exposure. Annals of Internal Medicine, 170(8), 531–537. https://doi.org/10.7326/M18-2809

Pew Research Center. (2023, November 9). Americans overwhelmingly say marijuana should be legal for medical or recreational use. https://www.pewresearch.org/short-reads/2023/11/09/americans-overwhelmingly-say-marijuana-should-be-legal-for-medical-or-recreational-use/

Gallup. (2023, November 8). Record-high 70% of Americans support legalizing marijuana. https://news.gallup.com/poll/512518/support-legal-marijuana-holds-record-high.aspx

GBD 2019 Mental Disorders Collaborators. (2022). Global, regional, and national burden of mental disorders, 1990–2019: A systematic analysis. The Lancet Psychiatry, 9(2), 137–150. https://doi.org/10.1016/S2215-0366(21)00395-3

Blackwell, D. L., Lucas, J. W., & Clarke, T. C. (2014). Summary health statistics for U.S. adults: National Health Interview Survey, 2012. Vital and Health Statistics. Series 10, Data from the National Health Survey, 260, 1–161. https://www.cdc.gov/nchs/data/series/sr_10/sr10_260.pdf

Centers for Disease Control and Prevention (CDC). (2023). Asthma Data and Surveillance. https://www.cdc.gov/asthma/asthmadata.htm

National Institute of Mental Health (NIMH). (2023). Major Depression. https://www.nimh.nih.gov/health/statistics/major-depression

Simonetto, D. A., Oxentenko, A. S., Herman, M. L., & Szostek, J. H. (2012). Cannabinoid hyperemesis: a case series of 98 patients. Mayo Clinic Proceedings, 87(2), 114–119. doi:10.1016/j.mayocp.2011.10.005

Sorensen, C. J., DeSanto, K., Borgelt, L., Phillips, K. T., & Monte, A. A. (2017). Cannabinoid Hyperemesis Syndrome: Diagnosis, Pathophysiology, and Treatment — A Systematic Review. Journal of Medical Toxicology, 13, 71–87. doi:10.1007/s13181-016-0595-z