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Medicinal cannabis product CBD does not affect driving ability, research finds

New research has confirmed taking even very high levels of cannabidiol (CBD), a medicinal product derived from cannabis, has no impact on people’s ability to drive.

Researchers from the University of Sydney have conducted a study of the impact of CBD on people’s cognitive ability, specifically whether it affects people’s ability to drive in the same way other medicines can.

New research confirms cannabidiol (CBD) does not impair people’s ability to drive even at high doses.


Lead research author Dr Danielle McCartney said on every measure they could not find any effect of CBD on a person’s ability to operate a vehicle.

“The finding speaks for itself somewhat, we didn’t find any effect on driving performance or cognitive function,” she said.

“We assessed a few different aspects of cognitive function, and when people reported subjectively how they felt, they didn’t report any signs or symptoms of intoxication,” she said.

The study featured 17 participants who were given either a placebo or 15 milligrams, 300 milligrams or 1500 milligrams of CBD (the maximum daily dose currently permitted).

No adverse cognitive effects were found from any level of the drug, with the tests including practical testing as well as self-reporting of any effects.

Participants undertook simulated driving exercises between 45-75 minutes after taking their assigned treatment, and then again at between 3.5 and four hours after.

CBD is becoming increasingly used around the world including in Australia for a range of conditions, from epilepsy and chronic pain to sleep disorders and anxiety conditions.

Previous University of Sydney research found 55,000 requests to access medicinal CBD have been approved in Australia since 2016.

CBD is a separate chemical from THC, which is the compound in cannabis which gets you “high” when used recreationally, and which does cause impairment to cognitive and driving ability.

Some medicinal cannabis products contain both CBD and THC, and are referred to as nabiximols, and are available to be prescribed in Australia, but at a higher drug classification than medicines which only contain CBD.

Police also conduct roadside drug tests which include tests for cannabis, although those tests specifically test for THC rather than CBD.

McCartney said they did conduct some research into whether the CBD medicines produced positive results on two of the most common tests used by police in NSW, and found that they did not.“We didn’t observe any false positive tests, so if people are taking CBD medication, they can be fairly confident that they will not impair their driving and they will not test positive for cannabis,” she said.

McCartney did sound a note of caution about the findings, stressing that they only looked at the effect of CBD on driving ability in isolation, and did not look at how it might interact with other medications.

“At the moment there are a number of drugs which are impairing which people are legally allowed to take and still drive, like opioids and benzodiazepines,” she said.

“CBD could interact with these substances, but whether it exacerbates their effects or has a different effect is something which needs more research to determine.”

The research has been published in the Journal of Psychopharmacology.

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