Marijuana Mythbusters: Debunking the DEA’s Claims

Despite widespread support for cannabis policy reform, prohibitionists continue to perpetuate misinformation to stigmatize cannabis consumers and prevent further reform progress. That's why the Marijuana Policy Project and Students for Sensible Drug Policy have teamed up to tackle these myths head-on, offering evidence-based insights to set the record straight!

CLAIM: Marijuana is a gateway drug.

REALITY: The vast majority of people who have used marijuana never try any other drugs. 

The so-called “Gateway Theory” has been debunked repeatedly. According to the CDC, there is limited evidence suggesting that using marijuana increases the risk of using other drugs.¹ Further, the National Academies of Sciences, Engineering, and Medicine reported that most people who use marijuana do not go on to use other drugs.² 

CLAIM: Legalization makes it easier for teens to access marijuana.

REALITY: Prohibition has failed miserably at keeping marijuana out of the hands of teens—but legalization has lowered use. 

Research has shown that legalizing marijuana does not increase teen use. Nationwide, both the CDC and Monitoring the Future survey results show significant drops in youth marijuana use between 2011 and 2024, while half of the country legalized and regulated marijuana for adults. In the two states with the earliest legalization laws, Washington and Colorado, adolescents’ marijuana use has decreased by over 35% since marijuana was legalized and regulated for adults 21 and older.³ 

CLAIM: Today’s marijuana is more dangerous.

REALITY: Like alcohol, there are more potent and less potent types of marijuana (but even the most potent marijuana is far less harmful than alcohol).

There is no evidence that higher-THC marijuana is more addictive or in any way more dangerous. By regulating marijuana, we can ensure it is packaged and labeled properly so consumers know what they are getting. 

CLAIM: Marijuana use causes schizophrenia.

REALITY: There is no compelling evidence demonstrating that marijuana causes schizophrenia in otherwise healthy individuals. 

Marijuana affects different people differently — like many substances, it can be problematic for some people and beneficial for others. Many opponents of legalization misrepresent a 2017 report by the National Academies of Sciences, Engineering, and Medicine, which found an association between marijuana use and schizophrenia, not that marijuana use causes schizophrenia. In fact, the report itself noted, “In certain societies, the incidence of schizophrenia has remained stable over the past 50 years despite the introduction of cannabis into those settings.”⁴ If marijuana causes schizophrenia, rates should rise if marijuana use goes up, but that has not happened. 

More recently, the National Academies of Sciences, Engineering, and Medicine noted that, “it’s difficult for scientists to untangle the link between cannabis use and schizophrenia and conclude if cannabis use causes the development of schizophrenia, or, alternatively, if schizophrenia may lead people to use cannabis.”⁵

CLAIM: Marijuana use makes you stupid/negatively impacts school performance.

REALITY: The claim that marijuana lowers IQ has been repeatedly debunked.

There is no conclusive evidence that marijuana use results in lowered IQ. In fact, many highly successful individuals across various fields have openly acknowledged their use of marijuana, demonstrating that it does not preclude high achievement. 

In its comprehensive 1999 report on marijuana, the National Academy of Sciences’ Institute of Medicine concluded there is no convincing data that demonstrates a causal relationship between marijuana use and “amotivational syndrome,” which is a term used to describe young people who drop out of social activities and show little interest in school, work, or other goal-directed activity.⁶ Further, researchers at University College London found “no relationship between marijuana use and IQ,” even among the heaviest users.⁷ Notably, the researchers also reported that alcohol use is strongly associated with a decline in IQ. 

CLAIM: Marijuana is addictive.

REALITY: Marijuana is significantly less addictive than alcohol and tobacco. 

A comprehensive federal study conducted by the National Academy of Sciences’ Institute of Medicine concluded that “millions of Americans have tried marijuana, but most are not regular users [and] few marijuana users become dependent on it … [A]lthough [some] marijuana users develop dependence, they appear to be less likely to do so than users of other drugs (including alcohol and nicotine), and marijuana dependence appears to be less severe than dependence on other drugs.”⁸ 

CLAIM: Marijuana causes brain damage.

REALITY: There is no conclusive evidence that marijuana kills brain cells or causes brain damage, even in long-term heavy consumers. 

According to research published in the Journal of Neuroscience, even daily marijuana use is not associated with changes in brain volume in adults or adolescents, noting it “lack[s] even a modest effect.” They also found significant inconsistencies among scientific papers that claimed marijuana causes parts of the brain to shrink.⁹

CLAIM: Marijuana is poorly regulated.

REALITY: Regulating marijuana like alcohol ensures consumers know exactly what they’re getting. 

Legalizing and regulating marijuana replaces the uncontrolled illicit market with a tightly regulated system. Authorities actually know what is being sold, who is selling it, where, when, and to whom. Regulated marijuana markets require businesses to test their products and adhere to strict labeling and packaging requirements that ensure marijuana is identifiable and consumers know what they are getting. Licensed marijuana stores are also overwhelmingly compliant with age-gating.¹⁰

CLAIM: Marijuana is more dangerous than alcohol and tobacco.

REALITY: There are far more health-related problems associated with alcohol and tobacco use than with marijuana use.

Marijuana is objectively less harmful than alcohol and tobacco to the consumer and society. Marijuana is less toxic, less harmful to the body, less addictive, and less likely to contribute to violent or reckless behavior. A study commissioned by the World Health Organization concluded the overall risks associated with marijuana are “small to moderate in size” and “unlikely to produce public health problems comparable in scale to those currently produced by alcohol and tobacco.”¹¹

CLAIM: Marijuana can kill you.

REALITY: There has never been a confirmed marijuana overdose death. 

The National Academies of Sciences, Engineering, and Medicine concluded in 2017 that no link has been established between marijuana and fatal overdoses.¹² Meanwhile, the CDC attributes about 35,000 deaths per year in the U.S. to alcohol use alone, including hundreds from overdoses. It attributes zero to marijuana.¹³

1 https://www.cdc.gov/cannabis/health-effects/using-other-drugs.html

2 https://nap.nationalacademies.org/catalog/24625/the-health-effects-of-cannabis-and-cannabinoids-the-current-state

3 https://www.mpp.org/issues/legalization/adult-use-legalization-corresponds-with-drop-in-teen-marijuana-use/

4 https://www.nationalacademies.org/news/2017/01/health-effects-of-marijuana-and-cannabis-derived-products-presented-in-new-report

5 https://www.nationalacademies.org/based-on-science/cannabis-the-relationship-between-cannabis-use-and-schizophrenia-is-complex

6 https://www.ncbi.nlm.nih.gov/books/NBK230709/

7 Mokrysc C., et al. “No relationship between moderate adolescent cannabis use, exam results or IQ, large study shows.” Annual Congress of the European College of Neuropsychopharmacology (ECNP). 2014.

8 U.S. National Academy of Sciences, Institute of Medicine, Marijuana and Medicine: Assessing the Science Base (Washington, D.C: National Academy Press, 1999).

9 Dobuzinskis, Alex, “Daily pot use not associated with brain shrinkage: Colorado study,” Reuters, February 5, 2015.

10 https://www.sciencedirect.com/science/article/abs/pii/S0306460323000916?via%3Dihub

11 Hall, Wayne. “A Comparative Appraisal of the Health and Psychological Consequences of Alcohol, Cannabis, Nicotine, and Opiate Use.” (1995). National Drug and Alcohol Research Centre.

12 National Academies of Sciences, Engineering, and Medicine. “The health effects of cannabis and cannabinoids: The current state of evidence and recommendations for research.” (2017).

13 Centers for Disease Control. “Vital Signs: Alcohol Poisoning Deaths — United States, 2010–2012.” Morbidity and Mortality Weekly Report Vol. 63 No. 53 (2015): 1238-1242.