Swinburne University of Technology researchers are undertaking a study investigating the effects of medical cannabis on drivers.
While a previous Australian study found consumption of cannabidiol (CBD) doesn’t impair driving ability, the intoxicating cannabinoid tetrahydrocannabinol (THC) can. But more research is required to identify if medicinal products containing THC that are available in Australia can contribute to increased risk of collision.
Dr Amie Hayley and Professor Luke Downey from Swinburne’s Centre for Human Psychopharmacology have received $345,951 from the Australian federal government’s Road Safety Innovation Fund for their research, which will be carried out in conjunction with Swinburne’s Drugs and Driving Research unit.
‘Using our high-fidelity driving simulator and eye monitoring technologies, we will test the relationship between eye movements and driver behaviour to better understand the impact of medicinal cannabis use on driving performance in patients, as well as healthy adults,’ said Professor Downey.
The study – said to be the first of its type in Australia – will be carried out Swinburne University’s driving simulator facility within the Drugs and Driving Research unit.
“Through our research, we hope to uncover potential solutions to mitigate the risk of road trauma for these patients and all road users,’ said Dr Hayley.
Among them may be driver monitoring systems that can detect a driver’s state and assess their capacity to drive safely. Such systems have already been successfully used to alert tired or distracted drivers.
Earlier this year, researchers at Australia’s Lambert Initiative for Cannabinoid Therapeutics at the University of Sydney found a ‘window of impairment’ of between three and 10 hours resulting from moderate to high doses of THC – but impairment is not a straightforward situation.
Lambert researchers also conducted a study back in 2019 comparing effects of THC-dominant and THC/CBD equivalent cannabis on simulated driving and cognitive performance.
In Australia, any detectable amount of THC in a driver can result in legal issues, even if there is no apparent impairment. This puts many patients using legally prescribed medicines containing THC under a de-facto driving ban given THC can be detected in the bloodstream for weeks after ingestion.