Addiction Drug Use Marijuana How Marijuana Affects Your Brain By Buddy T Buddy T Facebook Twitter Buddy T is an anonymous writer and founding member of the Online Al-Anon Outreach Committee with decades of experience writing about alcoholism. Learn about our editorial process Updated on October 28, 2020 Medically reviewed Verywell Mind articles are reviewed by board-certified physicians and mental healthcare professionals. Medical Reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more. by Steven Gans, MD Medically reviewed by Steven Gans, MD Steven Gans, MD is board-certified in psychiatry and is an active supervisor, teacher, and mentor at Massachusetts General Hospital. Learn about our Medical Review Board Print skodonnell / Getty Images More is known about the short-term effects of marijuana on the brain that is known about the long-term effects that the drug produces. Marijuana affects cannabinoid receptors which are found in brain regions that influence learning, memory, appetite, coordination, and pleasure. Affecting those receptors is how marijuana use produces the effects it has on users. What researchers do not fully understand is what effect that marijuana can have on the brain when someone uses the drug regularly over a long period of time. Neuroimaging studies show that there are differences between the brains of marijuana users and non-users. Impaired Neural Connectivity According to the National Institute on Drug Abuse, some of what scientists do not know is what the differences seen on the MRI images mean and how long the difference last if someone quits using marijuana. MRI image studies of teen brains show that those who regularly use marijuana display impaired neural connectivity in specific brain regions involved in a broad range of executive functions like memory, learning, and impulse control compared to non-users. One question this raises is to what degree this may reflect pre-existing differences that might lead to increased substance use and further changes in the brain. Loss of I.Q. Points A large, longitudinal study in New Zealand found that frequent marijuana use by adolescents was linked to up to a loss of 8 IQ points in mid-adulthood. That same study also found that teens who persistently used marijuana in adolescence but quit using still had a decline in IQ as adults. Largest Effect on Young Brains Researchers believe that marijuana's strongest long-term effects occur with young smokers whose brains are still developing neural connections. Research into the effects of marijuana on the brain has been hampered by the fact that most people who use marijuana also drink alcohol, or other substances, which can have their own negative effects on the brain. 4 Sources Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Jacobus J, Tapert SF. Effects of cannabis on the adolescent brain. Curr Pharm Des. 2014;20(13):2186–2193. doi:10.2174/13816128113199990426 Batalla A, Bhattacharyya S, Yücel M, et al. Structural and functional imaging studies in chronic cannabis users: a systematic review of adolescent and adult findings. PloS One. 2013;8(2):e55821. doi:10.1371/journal.pone.0055821 National Institute on Drug Abuse. Marijuana. What are marijuana's long-term effects on the brain?. Meier MH, Caspi A, Ambler A, et al. Persistent cannabis users show neuropsychological decline from childhood to midlife. Proc Natl Acad Sci U S A. 2012;109(40):E2657-E2664. doi:10.1073/pnas.1206820109 Additional Reading National Institute on Drug Abuse. Marijuana. DrugFacts National Institute on Drug Abuse. Want to know more?- some FAQs about marijuana. Marijuana: Facts for Teens National Institute on Drug Abuse. Marijuana. Research Report Series The Partnership at DrugFree.org. Marijuana. Drug Guide. By Buddy T Buddy T is an anonymous writer and founding member of the Online Al-Anon Outreach Committee with decades of experience writing about alcoholism. See Our Editorial Process Meet Our Review Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit Get Treatment for Addiction Advertiser Disclosure × The offers that appear in this table are from partnerships from which Verywell Mind receives compensation.