Landmark Research Study: Cannabidiol (CBD) in Cannabis Does Not Impair Driving

Landmark Research Study: Cannabidiol (CBD) in Cannabis Does Not Impair Driving

Cannabis Use Driving Test Vehicle

Vehicle utilized to check cannabis impact on driving. Tests happened on public roadways under controlled conditions in the Netherlands with Maastricht University. Credit: Maastricht University

Research shows cannabidiol safe for driving and THC impacts fade in hours.

A landmark study on how cannabis affects driving ability has shown that cannabidiol (CBD), a cannabis part now widely used for medical purposes, does not impair driving, while moderate amounts of the primary intoxicating component tetrahydrocannabinol (THC) produce moderate driving impairment lasting up to four hours.

The research study was led the Lambert Effort for Cannabinoid Therapies at the University of Sydney and conducted at Maastricht University in the Netherlands. It was released today in the distinguished Journal of the American Medical Association

Thomas Arkell

Lead author Dr Thomas Arkell from the Lambert Initiative for Cannabinoid Rehabs. Credit: University of Sydney

Lead author Dr. Thomas Arkell said: “These findings show for the very first time that CBD, when provided without THC, does not affect a topic’s capability to drive. That’s great news for those utilizing or thinking about treatment utilizing CBD-based products.”

There has been substantial growth in medical treatment using cannabis-related products in Australia and overseas.

The research involved individuals inhaling vaporized marijuana including different blends of THC and CBD, then opting for a 100- kilometer drive under regulated conditions on public highways both 40 minutes and 4 hours later on. Cannabis including mainly CBD did not hinder driving while cannabis including THC, or a THC/CBD mix, caused moderate impairment measured at 40 minutes later but not after four hours.

Dr. Arkell stated: “With marijuana laws changing internationally, jurisdictions are facing the issue of cannabis-impaired driving. These results offer much needed insights into the magnitude and period of disability triggered by various kinds of marijuana and can assist to assist road-safety policy not just in Australia however worldwide.”

” Road security is a primary concern,” Dr. Arkell stated. “These results need to allow for evidence-based laws and guideline for people getting medical marijuana.”

Iain McGregor

Professor Iain McGregor is Academic Director at the Lambert Effort for Cannabinoid Rehabs. Credit: University of Sydney

The Academic Director of the Lambert Effort, Professor Iain McGregor, stated: “We were thrilled to have the opportunity to collaborate with Teacher Jan Ramaekers and his group on this study. Studying the effects of marijuana on driving with such accuracy in a real-world context is extremely important.

” The results should reassure people using CBD-only items that they are most likely safe to drive, while assisting patients using THC-dominant products to understand the period of impairment.”


The research study involved giving 26 healthy individuals four different kinds of cannabis in a random order to vaporize on four different celebrations. Each individual’s driving efficiency was then examined on the road in real-world conditions along a 100- kilometer stretch of public highway in a double control car with a driving trainer present.

The tests were done at Maastricht University in the Netherlands utilizing a reputable clinical test that determines basic deviation of automobile position (SDLP), an index of lane weaving, swerving and overcorrecting. SDLP increases under the impact of alcohol and drugs such as Valium and Stilnox.

Individuals vaporized cannabis including primarily THC, primarily CBD, THC, and CBD in mix, or placebo marijuana (no active elements). The amount of THC vaporized by individuals was enough to trigger strong sensations of intoxication.

To test how the different types of cannabis impact driving, participants finished two one-hour, on-road highway driving tests starting at 40 minutes and at four hours after inhaling vaporized marijuana.

Teacher McGregor said: “With rapidly altering mindsets towards medical and non-medical usage of cannabis, driving under the impact of cannabis is emerging as a crucial and rather controversial public health issue.

” While some previous research studies have taken a look at the effects of marijuana on driving, a lot of have focused on smoked marijuana including just THC (not CBD) and have not precisely measured the duration of impairment.

” This is the first research study to show the lack of CBD impacts on driving and to also provide a clear sign of the duration of THC impairment.”

Reference: “Result of Cannabidiol and Δ 9– Tetrahydrocannabinol on Driving Performance: A Randomized Medical Trial” by Thomas R. Arkell, PhD; Frederick Vinckenbosch, MSc; Richard C. Kevin, PhD; Eef L. Theunissen, PhD; Iain S. McGregor, PhD and Johannes G. Ramaekers, PhD, 1 December 2020, JAMA21218

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