A new study finds no effect from medicinal cannabis on driving. 

The study indicates that when used as prescribed for chronic health conditions, medical cannabis does not impair simulated driving performance.

The study involved 40 participants with various chronic conditions who were assessed in a driving simulator before and after taking their prescribed dose of medical cannabis. 

Results showed no significant impairment in driving abilities 2.5 hours after consumption, nor was there any residual effect observed at 5 hours post-consumption.
“Our main finding was the absence of impairment on a simulated highway driving task,” said Brooke Manning, the paper’s lead author. 

“We noted that patients consuming their medication as prescribed drove with slightly greater consistency in highway driving speed and reported a decrease in the perceived effort required to drive.”

Manning also cautioned that the study had a relatively small sample size and its results are specific to patients undergoing stable, long-term medical cannabis treatment for refractory conditions.

This research comes at a time when medicinal cannabis use is on the rise in Australia, with significant increases in prescriptions over the last 18 months, according to the Therapeutic Goods Administration (TGA). 

Dr Thomas Arkell, another contributor to the study, says there is a need for clinical evidence to support the anecdotal benefits reported by patients, particularly those suffering from chronic pain.

Arkell is leading a longitudinal study at Swinburne that explores the cognitive and health effects of medical cannabis over a 12-week period, focusing on individuals with chronic pain who have never used cannabis before.

This study's findings are particularly relevant as, in all Australian jurisdictions except Tasmania, patients prescribed medical cannabis containing THC are prohibited from driving. The full study is accessible here.