Older adults may be more impaired by cannabis than younger users due to age-related changes in metabolism, cognition, and the endocannabinoid system — a growing concern as cannabis use rises among seniors.
Older adults who use cannabis and drive, geriatricians prescribing medical cannabis, traffic safety researchers, family members of older cannabis users.
What the researchers found
This paper synthesized evidence on a collision of trends: the growing population of adults over 65 who drive, increasing cannabis use among older adults for medical and recreational purposes, and age-related factors that may amplify cannabis impairment.
Older drivers already have more crashes per mile driven and are more likely to be injured or killed in crashes of similar magnitude. Cannabis (primarily through THC) compromises the sensory and neurocognitive abilities necessary for safe driving, and acute use is associated with increased motor vehicle crash rates including fatal ones.
The review identified several reasons why older adults may be more vulnerable to cannabis impairment. Changes in body composition and pharmacokinetics alter how THC is metabolized and distributed — potentially producing higher effective brain concentrations from the same dose. Age-related declines in neurocognitive function compound the cognitive effects of THC. And changes in the brain's endocannabinoid system with aging may alter sensitivity to cannabinoid effects.
Despite this convergence of risk factors, cannabis use among older adults and its relationship to driving safety has received little research attention.
Why it matters
Cannabis use among adults over 65 is the fastest-growing demographic segment of cannabis consumers. Many use it for chronic pain, sleep, or anxiety — conditions common in older adults. The driving research has focused overwhelmingly on younger users, leaving a gap in understanding how cannabis affects driving in the population that is already most vulnerable behind the wheel.
The numbers in context
Adults over 65 are the largest growing driving population in the US. Older drivers have more crashes per mile driven. Cannabis-impaired driving is associated with increased crash rates including fatal crashes. Age-related changes in body composition, liver metabolism, neurocognition, and the endocannabinoid system may all amplify impairment.
How the study worked
Narrative review synthesizing evidence on older adult driving risk, cannabis-related driving impairment, age-related pharmacokinetic changes, neurocognitive aging, and endocannabinoid system changes with age. Identified the intersection of these factors as an under-recognized crash risk.
Who was studied
Not enough information provided in the abstract.
What this study cannot tell us
Narrative review based largely on extrapolation from separate bodies of evidence (driving research, aging research, cannabinoid pharmacology) rather than direct studies of cannabis-impaired older drivers. The degree to which age amplifies cannabis driving impairment is hypothesized rather than quantified. Individual variation in aging, cannabis tolerance, and driving ability is enormous.
How to read the evidence
Narrative review connecting multiple evidence streams — raises an important hypothesis about age-amplified impairment but direct evidence from older cannabis-using drivers is lacking.
When this study was published
Published in 2026, calling attention to a research gap that will become more urgent as both cannabis legalization and population aging continue.
The bigger picture
This connects the driving impairment literature (RTHC-00159, RTHC-00171, RTHC-00188) to the growing use of cannabis among older adults (RTHC-00223 on seniors with chronic pain and depression). The urine testing review (RTHC-00260) shows that current testing doesn't measure impairment, and this paper argues that the same THC dose may produce more impairment in an older driver than a younger one — making impairment assessment even more complex in this population.
Replication
Not stated in abstract.
Funding
Not reported in abstract.
Conflicts of interest
Not reported in abstract.
Questions still open
- What THC dose produces equivalent impairment in a 70-year-old compared to a 25-year-old? Should medical cannabis prescribers for older adults routinely assess driving status? Do older adults who use cannabis regularly develop tolerance that offsets the age-related vulnerability?
Read the original research
Cannabis Use in Older Individuals May Be an Important and Under-Recognized Risk Factor for Motor Vehicle Crashes.
Cannabis and cannabinoid research, 11(1), 5-10
Cannabis and Cannabinoid Research is a peer-reviewed journal focusing on the science of cannabis and cannabinoids.
Citation
Pearlson, Godfrey D; D'Souza, Deepak C; Marottoli, Richard A; Stevens, Michael C. (2026). Cannabis Use in Older Individuals May Be an Important and Under-Recognized Risk Factor for Motor Vehicle Crashes.. Cannabis and cannabinoid research, 11(1), 5-10. https://doi.org/10.1177/25785125251410814