An Australian study investigating the impacts of THC oil on medicinal cannabis patients’ driving capabilities has revealed some interesting results that need to be interpreted with caution.
The study by researchers from the University Of Queensland and University of the Sunshine Coast involved validated video-based tests and 41 participants. Participants underwent two testing sessions (baseline and post-consumption), approximately one week apart.
The participants were assessed for:
- Hazard perception skill performance.
- Driving-related risk-taking behaviours.
- Self-perceived hazard perception skill performance.
- Self-perceptions of driving skills and safety.
Prior the post-consumption session, participants consumed a mean of 10.80 mg tetrahydrocannabinol (THC) and a mean of 16.05 mg cannabidiol (CBD).
The researchers found hazard perception skill performance did not significantly decline from baseline to post-consumption, but the way the participants perceived performance did. They were unable to accurately self-assess their performance;, however, this was regardless of whether they had consumed THC.
The study also found medicinal cannabis patients engaged in compensatory strategies; reducing their speed and increasing their following distance following the consumption of THC. But gap acceptance behaviour (a gap in traffic participants would be willing to pull out into) remained unchanged.
As usual, more research is needed and these results certainly shouldn’t be seen as any sort of encouragement to drive while impaired.
In their conclusion, the researchers stated:
“As the uptake of medicinal cannabis increases throughout Australia and other jurisdictions globally, developing a comprehensive understanding of the acute effects of THC on both objective and perceived driving performance will be crucial for guiding future road safety legislation in this area.”
The study has been published in the journal Pharmapsychology.
The issue of THC and driving is a hot-button topic in Australia. In most Australian jurisdictions, driving with any detectable level of THC in the bloodstream is illegal and can lead to loss of licence, even if there is no impairment. Given THC can remain detectable for up to weeks after consumption, medical cannabis use basically means patients are subjected to a self-imposed ban to avoid risk of prosecution.
Another study by the same research group looked at the acute effects of medically prescribed oral and vaporised delta-9-tetrahydrocannabinol on cognitive functions important for driving.
