Cannabis Legalization Drives New Users Rather Than Heavier Use Among Existing Users | Research

The takeaway

Recreational cannabis legalization increased the likelihood of any cannabis use by about 10% but did not increase frequency among existing users, with the greatest uptake among groups that historically used less: older adults, women, White adults, and college graduates.

Cannabis policy makers, public health planners, clinicians counseling patients about cannabis, and researchers studying legalization effects.

What the researchers found

Legalization was associated with 44% lower odds of zero cannabis use (95% CI=40-48%), indicating more people trying cannabis, but not with greater frequency among existing users — and groups with historically lower use (age 60+, female, White, college-educated) showed the strongest response with 1-2 percentage point increases.

Why it matters

This clarifies a key policy debate: legalization is expanding who uses cannabis rather than intensifying use among those who already do — information critical for designing proportionate public health responses.

The numbers in context

N=859,600; 38 states; 44% lower odds of zero use; 0.94 percentage point increase in use prevalence (9.8% relative increase); greatest increases among age 60+, female, White, college-educated (1-2 pp increases; all interaction p<0.1)

How the study worked

Quasi-experimental difference-in-differences analysis of 2016-2023 BRFSS data from 859,600 adults in 38 states, using zero-inflated negative binomial and probit regressions with demographic/policy controls and state/year fixed effects.

What this study cannot tell us

BRFSS self-report may underestimate use; 30-day use window may miss patterns; difference-in-differences assumes parallel trends; implementation heterogeneity across states; cannot separate legalization from commercialization effects.

How to read the evidence

Very large quasi-experimental study with robust methodology and comprehensive subgroup analyses, providing strong evidence for differential legalization effects.

When this study was published

Published 2026; covers 2016-2023 across 38 US states.

The bigger picture

Legalization's primary effect is democratizing cannabis use across demographics rather than creating heavier users — a finding that should reassure some concerns while highlighting the need for education among new user populations.

Questions still open

Will these new users eventually increase frequency? Do new older/female users face different health risks? Would pre-legalization education prevent uptake among groups responding most to legalization?

Common questions

Does legalization make people use more cannabis?

It makes more people use cannabis (about 10% increase in prevalence), but those who already used didn't increase their frequency — legalization primarily brings new users in rather than intensifying existing use.

Who starts using cannabis after legalization?

Older adults (60+), women, White adults, and college graduates — groups that historically used cannabis at lower rates — showed the biggest increases in use after legalization.

Read the original research

The Impact of Recreational Cannabis Legalization on Cannabis Use in U.S. Adults From 2016 to 2023: A Quasi-Experimental Study.

American journal of preventive medicine, 108221

View on PubMed ↗Publisher’s paper ↗

Citation

Hawkins, Summer Sherburne; Baidoo, Christopher E; Coley, Rebekah Levine; Centanni, Ryan S; Baum, Christopher F. (2026). The Impact of Recreational Cannabis Legalization on Cannabis Use in U.S. Adults From 2016 to 2023: A Quasi-Experimental Study.. American journal of preventive medicine, 108221. https://doi.org/10.1016/j.amepre.2025.108221