Marijuana Legalization Impact Report
Lessons learned from state marijuana legalization. More than a decade after Colorado and Washington opened the first recreational stores, SAM gathered the federal and state data, government surveys and peer-reviewed research on what legalization has meant for health, kids, roads, crime, the illegal market and state budgets. Every figure is cited so you can trace it to the source.
This is not the marijuana of the 1990s
Commercialization rewards potency. The plant has quadrupled in THC content, concentrates approach pure THC, and use has climbed with availability.
Average THC potency of marijuana
Percent THC by weight, seized samples; concentrates sold in legal states
University of Mississippi potency monitoring program; Impact Report, high-potency marijuana. Full breakdown: Marijuana potency: how strong is weed today?
Past-year marijuana use, United States
People 12 and older, indexed to 2012
Americans reported past-year marijuana use in 2023, up 88 percent since 2012.
SAMHSA, National Survey on Drug Use and Health, 2023
What high-potency marijuana does to the body and brain
The strongest findings in the report come from peer-reviewed studies of today’s products, not the low-potency marijuana of earlier decades.
Psychosis risk
Odds of a psychotic disorder, daily high-potency users versus non-users
Di Forti et al., The Lancet Psychiatry
Heart attack and stroke
Higher risk with daily marijuana use, compared with non-users
Journal of the American Heart Association, 2024
Head and neck cancers
Higher rates associated with marijuana use, range across cancer types
JAMA Otolaryngology, 2024
Legal stores, younger users, more poisonings
National averages hide the state-level picture. Where marijuana is sold commercially, kids are exposed earlier, use more heavily and end up in the hospital more often.
Accidental edible marijuana exposures, children under six
Poison center cases, indexed to 2017
Pediatrics, 2023
Teens who use daily
Share of teen users who use the substance every day
National Survey on Drug Use and Health
Where Massachusetts teens get it
Likelihood of buying from a licensed store versus a vape shop
Impact Report, youth
Youth hospital visits involving marijuana
Share of substance-related hospital visits, ages 12 to 21, 2016 to 2021
Impact Report, youth
Roads, crime, homelessness and the illegal market
Legalization was sold as a way to shrink the black market and free up police. The data from legal states show the opposite.
Colorado traffic deaths involving marijuana
Share of all traffic fatalities
Colorado Department of Transportation. Full breakdown: Marijuana and driving: what legalization did to the roads
What rose after legalization
Measured increases cited in the report
Impact Report: homelessness, crime, youth, emergency admissions
California: illegal grows versus legal grows
The largest legal market in the country
Impact Report, underground market
Marijuana-related emergency visits by race, 2023
Visit rate, Black residents compared with white residents
Impact Report, marginalized populations
The tax windfall that never came
Campaigns promise schools and roads. In practice marijuana taxes are a rounding error in state budgets, and most communities that can opt out of retail sales do.
Marijuana taxes as a share of state revenue
Share of total state tax revenue
U.S. Census Bureau, 2024; California Department of Tax and Fee Administration
Communities that said no to marijuana stores
Share of local jurisdictions opting out of retail sales
Rocky Mountain HIDTA; Impact Report, local opt-outs
Contents of the 2026-2027 edition
- Data and policy background
- Research on harms caused by marijuana
- Data highlights
- Commercialization: a growing concern
- High-potency marijuana
- Mental health
- Physical health
- Co-use with other substances
- Vaping
- Emergency room and hospital admissions
- Youth
- Young adults
- Marginalized populations
- Homelessness
- Impaired driving
- Crime
- A thriving underground market
- An unfulfilled promise: tax revenue
- Localities opting out of retail shops
- “Legal” products are unsafe
- Environmental contamination
- Threats to pets
- Hemp-derived intoxicants
- Canada
- Recommendations
- Reference list
What SAM recommends
Policymakers and the public need real-time data on both the consequences of legalization and its costs. Until that exists, the report recommends four things.
Stop expanding commercial marijuana until the data on its consequences and costs are in.
In places that have already legalized, implement public health measures such as caps on THC potency.
Significantly curtail the marijuana industry’s influence on policy.
Track emergency admissions, potency and price trends in legal and illegal markets, school incidents, youth-facing advertising, marijuana-involved crashes, mental health effects, treatment demand, the cost of implementing legalization, workplace impacts, and effects on minority communities and the environment.
The arguments against legalization, in plain language · Who opposes marijuana legalization · SAM’s policy work · Research library · Deep Dives
About the report
What is the SAM Legalization Impact Report?
An annual report from Smart Approaches to Marijuana that compiles publicly available federal and state data, government health surveys, investigative findings and peer-reviewed studies on what has happened in states that legalized recreational marijuana. The 2026-2027 edition covers health, youth, public safety, the illegal market, tax revenue, local opt-outs, product safety, the environment, hemp-derived intoxicants and Canada, with a full reference list.
Where does the data in the report come from?
Primary sources: the National Survey on Drug Use and Health, CDC and state health department data, poison control centers, state impact reports such as Colorado’s, law enforcement and DEA reporting, U.S. Census Bureau tax data, and peer-reviewed journals including The Lancet Psychiatry, JAMA and Pediatrics. Every figure is cited in the reference list so readers can trace it.
Has marijuana legalization increased teen use?
The states with the highest teen marijuana use all have legal recreational marijuana, cannabis use disorder among 12 to 17 year olds rose 25 percent in legalized states, and in Massachusetts teens were twice as likely to buy marijuana from a store as tobacco from a vape shop. National averages hide the state-level picture.
How much tax revenue does legal marijuana produce?
Less than campaigns promise. The U.S. Census Bureau found marijuana excise taxes never exceeded 1.5 percent of any state’s tax revenue. In California, the largest market, marijuana taxes were about half of one percent of the state budget, and the state cut marijuana taxes in 2022 to rescue failing licensed businesses.
What does SAM recommend?
Pause further legalization, implement public health measures such as potency caps where marijuana is already legal, curtail the industry’s influence on policy, and fund real-time data collection on emergency admissions, potency, youth exposure, impaired driving, treatment demand and the cost of legalization to states, workplaces and communities.
Bring the data to your community.
SAM trains coalitions, parents, clinicians and officials on what the evidence says and how to use it.
