Cannabis Legalization Increased Cannabis Use But Did Not Affect Tobacco Use or Co-Use

In a national US cohort tracked from 2017-2021, cannabis use rose 3.3% while tobacco declined 1.9%, with both medical and recreational legalization increasing cannabis use but having no spillover effect on tobacco or co-use.

Pravosud, Vira et al.·The International journal on drug policy·2024·Strong EvidenceLongitudinal Cohort
RTHC-05634Longitudinal CohortStrong Evidence2024RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Longitudinal Cohort
Evidence
Strong Evidence
Sample
N=9,003

What This Study Found

Cannabis use increased 3.3% from 2017-2021 while tobacco/nicotine use declined 1.9%. Both medical and recreational legalization were associated with increased cannabis use, with recreational legalization having 1.13 times larger effect. Neither type of legalization was associated with changes in tobacco/nicotine use or co-use of cannabis and tobacco.

Key Numbers

9,003 participants in 2017; cannabis use +3.3%; tobacco use -1.9%; co-use +0.2% (not significant); recreational legalization 1.13x larger effect than medical; age range 18-94

How They Did This

Longitudinal study using a nationally representative web-based panel of 9,003 US adults surveyed in 2017, 2020, and 2021, with weighted adjusted binary logistic GEE models assessing legalization associations.

Why This Research Matters

A major concern about cannabis legalization has been potential spillover effects on tobacco use or development of polysubstance use patterns. This study provides reassurance that legalization increases cannabis use without worsening tobacco or co-use patterns.

The Bigger Picture

This is important for policy because it suggests that cannabis legalization's effects are cannabis-specific rather than driving broader substance use changes. The tobacco decline continuing during cannabis expansion challenges the 'gateway' narrative.

What This Study Doesn't Tell Us

Self-reported substance use. Panel attrition (70% and 74% retention). Cannot account for all confounders. Binary cannabis use measure does not capture frequency or quantity changes.

Questions This Raises

  • ?Will longer-term legalization eventually affect co-use patterns?
  • ?Does legalization change the demographic profile of cannabis users over time?

Trust & Context

Key Stat:
Cannabis legalization had no spillover effect on tobacco use or co-use
Evidence Grade:
Nationally representative longitudinal panel with appropriate modeling, though panel attrition and self-report are limitations.
Study Age:
Published in 2024 with 2017-2021 data.
Original Title:
Cannabis legalization and changes in cannabis and tobacco/nicotine use and co-use in a national cohort of U.S. adults during 2017-2021.
Published In:
The International journal on drug policy, 134, 104618 (2024)
Database ID:
RTHC-05634

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-ControlFollows or compares groups over time
This study
Cross-Sectional / Observational
Case Report / Animal Study

Follows a group of people over time to track how outcomes develop.

What do these levels mean? →

Frequently Asked Questions

Does cannabis legalization increase tobacco use?

No. This study found tobacco use continued declining in states that legalized cannabis, with no spillover effect.

Does legalization increase cannabis use?

Yes. Both medical and recreational legalization were associated with increased cannabis use, with recreational having a slightly larger effect.

Read More on RethinkTHC

Cite This Study

RTHC-05634·https://rethinkthc.com/research/RTHC-05634

APA

Pravosud, Vira; Glantz, Stanton; Keyhani, Salomeh; Ling, Pamela M; Lempert, Lauren K; Hoggatt, Katherine J; Hasin, Deborah; Nguyen, Nhung; Graham, Francis Julian L; Cohen, Beth E. (2024). Cannabis legalization and changes in cannabis and tobacco/nicotine use and co-use in a national cohort of U.S. adults during 2017-2021.. The International journal on drug policy, 134, 104618. https://doi.org/10.1016/j.drugpo.2024.104618

MLA

Pravosud, Vira, et al. "Cannabis legalization and changes in cannabis and tobacco/nicotine use and co-use in a national cohort of U.S. adults during 2017-2021.." The International journal on drug policy, 2024. https://doi.org/10.1016/j.drugpo.2024.104618

RethinkTHC

RethinkTHC Research Database. "Cannabis legalization and changes in cannabis and tobacco/ni..." RTHC-05634. Retrieved from https://rethinkthc.com/research/pravosud-2024-cannabis-legalization-and-changes

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.