Marijuana: How Can It Affect Your Health?
Marijuana is the most commonly used illegal drug in the United States, with 37.6 million users in the past year,1 and marijuana use may have a wide range of health effects on the body and brain. Click on the sections below to learn more about how marijuana use can affect your health.
ADDICTION
About 1 in 10 marijuana users will become addicted. For people who begin using before the age of 18, that number rises to 1 in 6. 1-3
Some of the signs that someone might be addicted include:
- Unsuccessful efforts to quit using marijuana.
- Giving up important activities with friends and family in favor of using marijuana.
- Using marijuana even when it is known that it causes problems fulfilling everyday jobs at home, school or work.4
People who are addicted to marijuana may also be at a higher risk of other negative consequences of using the drug, such as problems with attention, memory, and learning. Some people who are addicted need to smoke more and more marijuana to get the same high. It is also important to be aware that the amount of tetrahydrocannabinol (THC) in marijuana (i.e., marijuana potency or strength) has increased over the past few decades. The higher the THC content, the stronger the effects on the brain. In addition, some methods of using marijuana (e.g., dabbing, edibles) may deliver very high levels of THC to the user.5 Researchers do not yet know the full extent of the consequences when the body and brain (especially the developing brain) are exposed to high concentrations of THC or how recent increases in potency affect the risk of someone becoming addicted. 5
BRAIN HEALTH
Marijuana use directly affects the brain — specifically the parts of the brain responsible for memory, learning, attention, decision making, coordination, emotions, and reaction time.1
What are the short-term effects of marijuana on the brain?
Heavy users of marijuana can have short-term problems with attention, memory, and learning, which can affect relationships and mood.
What are the long-term effects of marijuana on the brain?
Marijuana also affects brain development. When marijuana users begin using as teenagers, the drug may reduce attention, memory, and learning functions and affect how the brain builds connections between the areas necessary for these functions.
Marijuana’s effects on these abilities may last a long time or even be permanent. This means that someone who uses marijuana may not do as well in school and may have trouble remembering things. 1-3
The impact depends on many factors and is different for each person. It also depends on the amount of tetrahydrocannabinol (THC) in marijuana (i.e., marijuana potency or strength), how often it is used, the age of first use, and whether other substances (e.g., tobacco and alcohol) are used at the same time.
Marijuana and the developing brain
Developing brains, like those in babies, children, and teenagers are especially susceptible to the hurtful effects of marijuana. Although scientists are still learning about these effects of marijuana on the developing brain, studies show that marijuana use by mothers during pregnancy may be linked to problems with attention, memory, problem-solving skills, and behavior problems in their children. 3-7
e-Checkup
is an interactive, confidential web survey that allows you to enter information about your cannabis use patterns and receive personalized feedback about your use. It enables you to compare your use to other college students, gives you accurate information about cannabis use norms, and discusses individual behaviors and helpful strategies to minimize unwanted effects of use.
Take the confidential e-Checkup Assessment
References: Content taken from the CDC (2021)
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Batalla A, Bhattacharyya S, Yücel M, et al. (2013). Structural and functional imaging studies in chronic cannabis users: a systematic review of adolescent and adult findings. PloS One. 8(2):e55821. doi:10.1371/journal.pone.0055821.
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Filbey, FM, et al., Long-term effects of marijuana use on the brain. (2014) Proc Natl Acad Sci USA. 111(47): p. 16913-8.
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Goldschmidt, L, et al. (2002). Richardson, Effects of prenatal marijuana exposure on child behavior problems at age 10. Neurotoxicol Teratol. 22(3): p. 325-36.
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Fried, PA, Watkinson, B, and Gray, R. Differential effects on cognitive functioning in 9- to 12-year olds prenatally exposed to cigarettes and marihuana. Neurotoxicol Teratol, 1998. 20(3): p. 293-306.
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Leech, SL, et al., (1999). Prenatal substance exposure: effects on attention and impulsivity of 6-year-olds. Neurotoxicol Teratol. 21(2): p. 109-18.
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Goldschmidt, L, et al., (2008) Prenatal marijuana exposure and intelligence test performance at age 6. J Am Acad Child Adolesc Psychiatry. 47(3): p. 254-63.
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El Marroun, H, et al., (2011). Intrauterine cannabis exposure leads to more aggressive behavior and attention problems in 18-month-old girls. Drug Alcohol Depend. 118(2-3): p. 470-4.
References
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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 Alcohol Depend. 115(1-2): p. 120-30.
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Hall, W, Degenhardt L. (2009). Adverse health effects of non-medical cannabis use. Lancet. 374(9698): p. 1383-91.
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Budney, AJ, Sargent JD, and Lee, DC. (2015). Vaping cannabis (marijuana): parallel concerns to e-cigs? Addiction. 110(11): p. 1699-704.
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American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: American Psychiatric Publishing.
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National Institute on Drug Abuse. Is marijuana addictive?external icon (2017) Rockville, MD: National Institutes of Health, National Institute on Drug Abuse.
