Men who use cannabis medically and recreationally are most likely to drive high
Among 17,405 cannabis users, men who used both medically and recreationally had a 40% probability of driving under the influence of cannabis, compared to 20% for women using medically only.
Quick Facts
What This Study Found
Male cannabis users who combined medical and recreational use had the highest probability of DUIC (40%), while female medical-only users had the lowest (20%). Women showed similar DUIC rates regardless of use reason (20-25%), while men varied widely (28-40%). The sex difference was most pronounced among combined medical/recreational users.
Key Numbers
17,405 cannabis users; 88.1% recreational, 7.8% medical, 4.1% both; DUIC probability: male combined users 40%, female medical-only 20%.
How They Did This
Cross-sectional analysis of 17,405 past-year cannabis users (18+) from the 2016-17 National Survey on Drug Use and Health, using multivariable logistic regression with sex-by-reason interaction.
Why This Research Matters
As both medical and recreational cannabis expand, understanding who is most likely to drive impaired helps target prevention. Men who use for both purposes emerge as the highest-risk group.
The Bigger Picture
The finding that medical cannabis users drive impaired at meaningful rates challenges the assumption that medical use is inherently more responsible. Combining medical and recreational use patterns appears to create the highest risk.
What This Study Doesn't Tell Us
Cross-sectional survey with self-reported DUIC; cannot establish that DUIC was actually impaired driving; does not assess actual impairment or crash risk; reasons for use may overlap with other risk factors.
Questions This Raises
- ?Why do men show more variation in DUIC by reason for use than women?
- ?Would targeted interventions for dual-purpose male users reduce cannabis-impaired driving?
Trust & Context
- Key Stat:
- 40% DUIC probability among male combined medical/recreational users
- Evidence Grade:
- Moderate: large nationally representative sample with appropriate statistical methods, but cross-sectional with self-reported outcomes.
- Study Age:
- Published 2020.
- Original Title:
- Sex differences in driving under the influence of cannabis: The role of medical and recreational cannabis use.
- Published In:
- Addictive behaviors, 110, 106525 (2020)
- Authors:
- Lloyd, Shawnta L, Lopez-Quintero, Catalina(6), Striley, Catherine W(3)
- Database ID:
- RTHC-02691
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Who is most likely to drive high?
Men who use cannabis for both medical and recreational purposes had the highest probability (40%) of driving under the influence of cannabis.
Do medical cannabis patients drive impaired?
Yes. Medical-only users still had meaningful DUIC rates (20-28% depending on sex), though lower than recreational or combined users.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-02691APA
Lloyd, Shawnta L; Lopez-Quintero, Catalina; Striley, Catherine W. (2020). Sex differences in driving under the influence of cannabis: The role of medical and recreational cannabis use.. Addictive behaviors, 110, 106525. https://doi.org/10.1016/j.addbeh.2020.106525
MLA
Lloyd, Shawnta L, et al. "Sex differences in driving under the influence of cannabis: The role of medical and recreational cannabis use.." Addictive behaviors, 2020. https://doi.org/10.1016/j.addbeh.2020.106525
RethinkTHC
RethinkTHC Research Database. "Sex differences in driving under the influence of cannabis: ..." RTHC-02691. Retrieved from https://rethinkthc.com/research/lloyd-2020-sex-differences-in-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.