According to a new study by scientists from the Lambert Initiative, CBD, an active component of cannabis does not impact driving ability.
The study also found that moderate THC intoxication lasts a few hours, with implications for drug-driving laws and managing medical cannabis.
Led by the Lambert Initiative for Cannabinoid Therapeutics at the University of Sydney and conducted at Maastricht University in the Netherlands, the study was published in the prestigious Journal of the American Medical Association.
Lead author Dr Thomas Arkell commented, “These findings indicate for the first time that CBD, when given without THC, does not affect a subject’s ability to drive. That’s great news for those using or considering treatment using CBD-based products.”
The study involved people inhaling vaporised cannabis containing different mixes of THC and CBD, then going for a 100-kilometre drive under controlled conditions on public highways both 40 minutes and four hours later.
While cannabis containing mainly CBD did not impair driving, cannabis containing THC, or a THC/CBD mixture, caused mild impairment measured at 40 minutes later but not after four hours.
Dr. Arkell remarked, “With cannabis laws changing globally, jurisdictions are grappling with the issue of cannabis-impaired driving. These results provide much needed insights into the magnitude and duration of impairment caused by different types of cannabis and can help to guide road-safety policy not just in Australia but around the world”.
“Road safety is a primary concern,” he added. “These results should allow for evidence-based laws and regulation for people receiving medical cannabis.”
The Academic Director of the Lambert Initiative, Professor Iain McGregor, stated, “We were delighted to have the opportunity to collaborate with Professor Jan Ramaekers and his team on this study. Studying the effects of cannabis on driving with such precision in a real-world context is incredibly important.
“The results should reassure people using CBD-only products that they are most likely safe to drive, while helping patients using THC-dominant products to understand the duration of impairment.”Professor McGregor added, “With rapidly changing attitudes towards medical and non-medical use of cannabis, driving under the influence of cannabis is emerging as an important and somewhat controversial public health issue.
“While some previous studies have looked at the effects of cannabis on driving, most have focused on smoked cannabis containing only THC (not CBD) and have not precisely quantified the duration of impairment.
“This is the first study to illustrate the lack of CBD effects on driving and to also provide a clear indication of the duration of THC impairment.”
