Driving Performance Unaffected In Regular Cannabis Users After 48 Hours Of Abstinence

Scientists from nan Center for Medicinal Cannabis Research (CMCR) astatine nan University of California San Diego School of Medicine recovered that, successful nan largest specified study to date, predominant cannabis users did not show impairments successful driving capacity aft astatine slightest 48 hours of abstinence. The caller findings person implications for nationalist wellness arsenic good arsenic nan enforcement of laws related to cannabis and driving.

Approximately three-quarters of Americans unrecorded successful a authorities wherever cannabis is legally available, and astir 15% of Americans presently usage cannabis. As cannabis usage becomes much widespread, knowing its effects connected regular activities for illustration driving is important to maintaining nationalist information and due authorities astir cannabis use.

While acute cannabis intoxication tin impair driving, it tin beryllium challenging to enforce cannabis and driving laws because, dissimilar alcohol, location is nary biologic trial (e.g., humor concentrations) that straight relates to cannabis intoxication. Tetrahydrocannabinol (THC), nan psychoactive compound successful cannabis, tin beryllium detected successful humor for respective days to weeks aft use, and successful urine for weeks aliases moreover months.

One unanswered mobility astir cannabis and driving is whether predominant cannabis users, who whitethorn aliases whitethorn not still person THC detectable successful their blood, acquisition reduced driving abilities erstwhile not actively high. To reply this question, researchers analyzed information from 2 studies. The first, a randomized objective trial, assessed driving capacity successful a sample of 191 cannabis users, each of whom had abstained for astatine slightest 48 hours. The 2nd study compared a subset of nan astir predominant users from nan first study pinch a smaller comparison group of group who don't usage cannabis. A driving simulator was utilized to measure driving capacity and imaginable impairment.

The researchers recovered nary indications of reduced driving expertise successful cannabis users who had abstained for astatine slightest 2 days. First-author Kyle Mastropietro, a postgraduate student successful nan San Diego State University/UC San Diego Joint Doctoral Program successful Clinical Psychology, commented, "We did not find immoderate narration betwixt driving performance, and cannabis usage history aliases clip of abstinence, nor humor THC concentrations. Of note, nan astir intensive users from nan group, who mostly utilized cannabis regular and smoked an mean of 4 joints per day, did nary worse during this play of abstinence than a healthy, non-using comparison group."

Thomas Marcotte, Ph.D., professor of psychiatry astatine UC San Diego School of Medicine and nan study's elder author, added, "The findings adhd to nan increasing assemblage of grounds that relying connected humor THC concentrations successful regular cannabis users arsenic imaginable indicators of impairment is not justified, fixed that THC whitethorn beryllium detectable galore days (or longer) aft use." Marcotte, who is besides nan co-director of nan CMCR, added that "the findings reenforce nan challenges successful relating findings from cognitive testing successful very predominant users who are abstinent to really they mightiness usability during real-world, overlearned behaviors for illustration driving."

The authors statement that this study was done successful a controlled laboratory environment, did not reside each imaginable driving scenarios, and nan nonuser comparison group was small. That said, nan findings do supply caller insights into nan imaginable risks and consequences of chronic cannabis use.

The study was published successful Psychopharmacology connected September 6, 2025. It was funded, successful part, by nan State of California grant to nan CMCR via Assembly Bill 266 (Bonta/Cooley/Jones-Sawyer/Lackey: Agreement #907).