Self-reported driving high was less common in states with legal cannabis
Cannabis users in states with recreational or medical legalization reported lower rates of driving under the influence of cannabis compared to users in states without legal cannabis.
Quick Facts
What This Study Found
Among 1,249 past-30-day cannabis users, the risk of driving within 3 hours of getting high was 59% lower in recreational states (RR 0.41) and 61% lower in medical-only states (RR 0.39) compared to states without legal cannabis. The exception was frequent users (20+ days/month) in medical states, who showed no difference from users in non-legal states.
Key Numbers
1,249 past-30-day cannabis users. Recreational states: RR 0.41. Medical states: RR 0.39. Frequent users in recreational states: RR 0.70. Frequent users in medical states: RR 0.87 (not significant).
How They Did This
Cross-sectional national survey (2016-2017) of 1,249 past-30-day cannabis users. Logistic regression adjusted for demographics, frequency of use, interaction between use frequency and legal status, calibration weights, and geographic clustering.
Why This Research Matters
A common concern about cannabis legalization is that it will increase impaired driving. This study suggests the opposite pattern, at least for self-reported behavior.
The Bigger Picture
The lower rates of self-reported impaired driving in legal states could reflect greater awareness of consequences, availability of delivery services, or cultural shifts in how cannabis is consumed in legal markets.
What This Study Doesn't Tell Us
Self-reported driving behavior may be subject to social desirability bias. Cross-sectional design cannot determine causation. 2016-2017 data predates many states' legalization.
Questions This Raises
- ?What mechanisms explain lower self-reported impaired driving in legal states?
- ?Do crash data corroborate these self-report findings?
Trust & Context
- Key Stat:
- 59% lower risk of driving high in recreational cannabis states
- Evidence Grade:
- National sample with appropriate adjustments, but self-report data on impaired driving and cross-sectional design limit conclusions.
- Study Age:
- Published in 2022 using 2016-2017 survey data.
- Original Title:
- Cannabis legalization and driving under the influence of cannabis in a national U.S. Sample.
- Published In:
- Preventive medicine reports, 27, 101799 (2022)
- Authors:
- Dutra, Lauren M(2), Farrelly, Matthew, Gourdet, Camille(2), Bradfield, Brian
- Database ID:
- RTHC-03822
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Does cannabis legalization increase impaired driving?
This study found the opposite: self-reported driving under the influence of cannabis was less common in both recreational and medical cannabis states compared to states without legal cannabis.
Were frequent users different?
Frequent users (20+ days/month) in recreational states still showed lower driving-high rates, but frequent users in medical-only states showed no significant difference from users in non-legal states.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-03822APA
Dutra, Lauren M; Farrelly, Matthew; Gourdet, Camille; Bradfield, Brian. (2022). Cannabis legalization and driving under the influence of cannabis in a national U.S. Sample.. Preventive medicine reports, 27, 101799. https://doi.org/10.1016/j.pmedr.2022.101799
MLA
Dutra, Lauren M, et al. "Cannabis legalization and driving under the influence of cannabis in a national U.S. Sample.." Preventive medicine reports, 2022. https://doi.org/10.1016/j.pmedr.2022.101799
RethinkTHC
RethinkTHC Research Database. "Cannabis legalization and driving under the influence of can..." RTHC-03822. Retrieved from https://rethinkthc.com/research/dutra-2022-cannabis-legalization-and-driving
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.