Teen Cannabis Use After Legalization: What the Studies Show

A 2024 study in JAMA Pediatrics found no net increase in adolescent substance use associated with recreational cannabis legalization or retail sales in the data it examined. That finding is relevant to the debate over youth access, but it does not prove that legalization always reduces teen use or makes cannabis safe for adolescents.

What the 2024 Study Examined

Coley and colleagues analyzed 2011–2021 Youth Risk Behavior Survey data from 47 states. Participants were students in grades 9–12, and the cannabis analysis included 898,271 students. They reported past-month use, not simply whether they had ever tried cannabis.

Retail sales were associated with 28% higher odds of zero cannabis use and 26% higher frequency among users. Together, these produced no statistically significant overall retail-sales effect. Legalization was associated with a reduction in the model’s total cannabis-use estimate. Some alcohol and e-cigarette outcomes also declined; cigarette findings were not significant.

Why the Statistical Distinctions Matter

Odds are not the same as percentage-point changes in the number of students using cannabis. Nor does a finding about no use during the previous month show that someone has never used it. Headlines that interchange these measures can make a result sound larger or more definitive than it is.

Population patterns also have more than one dimension. The proportion of students reporting any use can fall while the students who do use consume more frequently. That is why prevalence, frequency, problematic use, and health consequences deserve separate attention. One favourable measure does not settle all of those questions.

The study used repeated school surveys rather than randomly assigning states to policies. Statistical adjustment helps address differences between states and years, but it cannot eliminate every alternative explanation. Its observation period ended in 2021, so it does not describe every later market change.

The Wider Evidence Is Mixed

A 2024 systematic review and meta-analysis by Pawar and colleagues reached a different overall conclusion. Across the studies included in its analysis, recreational legalization was associated with a modest increase in past-month cannabis use among youth. The authors found little association for medical cannabis legalization and emphasized that effects differed by policy type and age group.

The review included adolescents and young adults, which should not be treated as one interchangeable population. Its more recent-study analysis found an association in both groups, with a larger estimate among young adults. These findings are enough to rule out the claim that every study concludes legalization reduces teen use.

Differences in populations, time periods, policy definitions, and analytical methods can produce different estimates. A study of whether a law was enacted is also asking a different question from one examining store openings, market maturity, or particular regulatory safeguards.

What Newer National Surveys Add

The NIH announcement of the 2025 Monitoring the Future findings reports that use of most drugs remained low among U.S. teens. The survey follows students in eighth, tenth, and twelfth grades and provides valuable national context.

A national trend is not, on its own, an estimate of legalization’s effect. It combines students living under different policies, alongside many social changes that can affect substance use. It also does not establish that every drug is declining: the announcement identifies increases in reported heroin use despite low absolute prevalence.

Possible Explanations Require Testing

Age checks at licensed stores, prevention efforts, changes in perceived risk, product availability, and access through peers or family are possible influences on youth use. Their existence does not tell us which factor caused a particular survey result.

Legalization should not be assumed to eliminate illicit supply. Likewise, describing cannabis as normal adult behaviour does not establish that it reduces adolescents’ curiosity. Claims about those mechanisms need their own evidence rather than being presented as conclusions of a study that did not directly test them.

Youth Health Remains a Separate Concern

CDC guidance on cannabis and teens describes risks involving learning, memory, attention, and cannabis use disorder. Starting young and using more frequently are particular concerns. A policy study finding no increase in overall use does not negate those individual health risks.

For families, a useful discussion can be factual and respectful while still explaining that adult legalization is not a safety endorsement for adolescents. Frequent use, difficulty cutting down, or problems with school and daily functioning warrant attention from a qualified health professional.

What Can Be Concluded?

The original study offers evidence against an inevitable population-wide surge in teen use following legalization. It does not establish that every legalization model reduces use, that all research agrees, or that youth protection no longer needs scrutiny. Continued monitoring should consider both how many adolescents use cannabis and what happens among those who use it frequently.

Original Study Reference

Coley, R. L., Carey, N., Kruzik, C., Hawkins, S. S., and Baum, C. F. (2024). Recreational cannabis legalization, retail sales, and adolescent substance use through 2021. JAMA Pediatrics, 178(6), 622–625. doi:10.1001/jamapediatrics.2024.0555.