Policies that legalize marijuana for recreational use allow possession of a limited amount of marijuana for personal, non-medical use. Marijuana use is illegal in the United States at the federal level. Recreational use is prohibited in most states. Some states allow recreational use; allowances regarding home cultivation, maximum possession and purchase amounts, marketing and advertising restrictions, and taxes on marijuana products vary (Maxwell 2016, Pacula 2017*).
Expected Beneficial Outcomes (Rated)
Reduced drug use
Other Potential Beneficial Outcomes
Reduced alcohol use
Evidence of Effectiveness
There is insufficient evidence to determine whether legalizing recreational marijuana increases marijuana use (Hall 2016*, Maxwell 2016, Cerda 2017*, Mason 2016*) or affects overall crime rates (Guttmannova 2016*, Maier 2017*, RAND-Kilmer 2012, Caulkins 2012*). Available evidence suggests that legalizing marijuana for recreational use may decrease youth’s perceived risk (Maxwell 2016, Estoup 2016*, Cerda 2017*, Ryan 2017), possibly increasing their use (Maxwell 2016, Cerda 2017*, Mason 2015). Legalization may also increase the risk of children’s unintentional toxic ingestions of marijuana products (Wang 2016*, RAND-Pacula 2017, Wilkinson 2016*) and increase marijuana-impaired driving and crashes (HLDI 2017, AAA-Tefft 2016, NHTSA-Ramirez 2016, Maxwell 2016). However, additional evidence is needed to confirm effects.
Following legalization in Colorado and Washington, the number of marijuana-related poison center calls and emergency room visits increased (Maxwell 2016); alcohol consumption did not appear to change (Guttmannova 2016*). Marijuana-related arrest rates decreased two years after Colorado legalized marijuana for recreational use; however, marijuana-related arrest rates among blacks remained substantially higher than rates among whites and Hispanics (Males 2014).
Researchers suggest that legalizing marijuana for recreational use reduces its price (Hall 2016*, RAND-Kilmer 2012), which could increase the likelihood of use (Hall 2016*, RAND-Kilmer 2012) and lower the age of initiation (Van Ours 2012). Marijuana initiation before adulthood may increase the likelihood of dependence and related harms (Caulkins 2012*, Wilsey 2008*, Bostwick 2012); initiation over the age of 25 rarely results in dependence (Bostwick 2012).
Smoking marijuana may lead to respiratory problems, heart attacks, cancers, and cognitive impairment (Wilkinson 2016*, Leung 2011). Marijuana use may also increase the risk of psychotic and schizophrenic symptoms and may worsen schizophrenia, especially in genetically susceptible individuals and youth (Caulkins 2012*, Bostwick 2012). The American Academy of Pediatrics (AAP) recommends routine screening and counseling for parents and youth about potential harms including damage to brain development, psychiatric illness, dropout, and suicide, particularly if recreational marijuana use is legal (Ryan 2017, AAP-Ammerman 2015*).
Impact on Disparities
As of October 2019, recreational marijuana is legal for adults age 21 or older in eleven states (Alaska, California, Colorado, Illinois, Massachusetts, Maine, Michigan, Nevada, Oregon, Vermont, and Washington) and Washington DC (NCSL-Marijuana). These states also regulate licensing and location of recreational marijuana dispensaries; every state but Washington allows residents to cultivate a small amount of marijuana for personal use (WA-Marijuana use guide). Detailed regulations on the maximum amount of marijuana possession, use, transfer, and home grow vary by state (NCSL-Marijuana).
As of August 2019, 33 states and Washington DC allow residents to use medical marijuana (NCSL-MMLs).
Citations - Evidence
* Journal subscription may be required for access.
Hall 2016* - Hall W, Lynskey M. Evaluating the public health impacts of legalizing recreational cannabis use in the United States. Addiction. 2016;111(10):1764-1773.
Maxwell 2016 - Maxwell JC, Mendelson B. What do we know about the impact of the laws related to marijuana? Journal of Addiction Medicine. 2016;10(1):3-12.
Cerda 2017* - Cerdá M, Wall M, Feng T, et al. Association of state recreational marijuana laws with adolescent marijuana use. JAMA Pediatrics. 2017;171(2):142-149.
Mason 2016* - Mason WA, Fleming CB, Ringle JL, et al. Prevalence of marijuana and other substance use before and after Washington State’s change from legal medical marijuana to legal medical and nonmedical marijuana: Cohort comparisons in a sample of adolescents. Substance Abuse. 2016;37(2):330-335.
Guttmannova 2016* - Guttmannova K, Lee CM, Kilmer JR, et al. Impacts of changing marijuana policies on alcohol use in the United States. Alcoholism: Clinical & Experimental Research. 2016;40(1):33-46.
Maier 2017* - Maier SL, Mannes S, Koppenhofer EL. The implications of marijuana decriminalization and legalization on crime in the United States. Contemporary Drug Problems. 2017;44(2):125-146.
RAND-Kilmer 2012 - Kilmer B, Caulkins JP, Pacula RL. Marijuana legalization: What we know and what we don’t. In: RAND Congressional Briefing Series. Santa Monica: RAND Corporation; 2012.
Caulkins 2012* - Caulkins JP, Hawken A, Kilmer B, Kleiman MAR. Marijuana legalization: What everyone needs to know. New York: Oxford University Press; 2012.
Estoup 2016* - Estoup AC, Moise-Campbell C, Varma M, Stewart DG. The impact of marijuana legalization on adolescent use, consequences, and perceived risk. Substance Use & Misuse. 2016;51(14):1881-1887.
Ryan 2017 - Ryan SA, Ammerman SD, AAP Committee on Substance Use and Prevention. Counseling parents and teens about marijuana use in the era of legalization of marijuana. Pediatrics. 2017;139(3):e20164069.
Mason 2015 - Mason J, Wheeler W, Brown MJ. The economic burden of exposure to secondhand smoke for the child and adult never smokers residing in US public housing. Public Health Reports. 2015;130(3):230-244.
Wang 2016* - Wang GS, Le Lait MC, Deakyne SJ, et al. Unintentional pediatric exposures to marijuana in Colorado, 2009-2015. JAMA Pediatrics. 2016;170(9):e160971.
RAND-Pacula 2017 - Pacula RL. Regulating medical marijuana markets: Insights from scientific evaluations of state experiments. Santa Monica, CA: RAND Corporation; 2017.
Wilkinson 2016* - Wilkinson ST, Yarnell S, Radhakrishnan R, Ball SA, D’Souza DC. Marijuana legalization: Impact on physicians and public health. Annual Review of Medicine. 2016;67(1):453-466.
HLDI 2017 - Highway Loss Data Institute (HDLI). Recreational marijuana and collision claim frequencies. HLDI Bulletin. 2017;34(14).
AAA-Tefft 2016 - Tefft BC, Arnold LS, Grabowski JG. Prevalence of marijuana involvement in fatal crashes: Washington, 2010-2014 (May 2016). Washington, DC: AAA Foundation for Traffic Safety; 2016.
NHTSA-Ramirez 2016 - Ramirez A, Berning A, Carr K, et al. Marijuana, other drugs, and alcohol use by drivers in Washington State. Washington, DC: National Highway Traffic Safety Administration (NHTSA); 2016.
Males 2014 - Males M, Buchen L. Reforming marijuana laws: Which approach best reduces the harms of criminalization? A five-state analysis. San Francisco, CA: Center on Juvenile and Criminal Justice (CJCJ); 2014.
Van Ours 2012 - Van Ours JC. The long and winding road to cannabis legalization. Addiction. 2012;107(5):872-3.
Wilsey 2008* - Wilsey B, Marcotte T, Tsodikov A, et al. A randomized, placebo-controlled, crossover trial of cannabis cigarettes in neuropathic pain. Journal of Pain. 2008;9(6):506-21.
Bostwick 2012 - Bostwick JM. Blurred boundaries: The therapeutics and politics of medical marijuana. Mayo Clinic Proceedings. 2012;87(2):172-86.
Leung 2011 - Leung L. Cannabis and its derivatives: Review of medical use. Journal of the American Board of Family Medicine. 2011;24(4):452-62.
AAP-Ammerman 2015* - Ammerman S, Ryan S, Adelman WP. The impact of marijuana policies on youth: Clinical, research, and legal update. Pediatrics. American Academy of Pediatrics (AAP). 2015;135(3):e769-e785.
Citations - Implementation Examples
* Journal subscription may be required for access.
NCSL-Marijuana - National Conference of State Legislatures (NCSL). Marijuana overview.
WA-Marijuana use guide - Washington State Liquor and Cannabis Board. Marijuana use in Washington State: An adult consumer’s guide. 2016.
NCSL-MMLs - National Conference of State Legislatures (NCSL). State medical marijuana laws (MMLs).
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