New research finds no impairment on simulated driving performance from medical cannabis when used as prescribed

A new study conducted by researchers at Swinburne University of Technology's Centre for Human Psychopharmacology has made significant findings in the field of medical cannabis use. Published in the Journal of Psychopharmacology in February 2024, the research suggests that medical cannabis, when used as prescribed for a chronic health condition, has a negligible impact on simulated driving performance.

The open-label study assessed the influence of prescribed medical cannabis on simulated driving performance among 40 patients with a range of chronic health conditions. Participants had their driving ability assessed in a simulator before and after consuming a standard dose of their prescribed medication.

The findings revealed no notable impairment in driving capabilities during a highway driving simulation at 2.5 hours post consumption, nor was there any residual impairment on driving performance at 5 hours.

Brooke Manning, the paper's lead author, emphasized the study's crucial role in generating evidence on the safety and effectiveness of medical cannabis treatment.

"Our main finding was the absence of impairment on a simulated highway driving task. 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," she said.

"It's crucial to highlight that this study, while revealing, involved a relatively small sample size and its results apply specifically to patients undergoing stable, long-term medical cannabis treatment for refractory conditions."

Swinburne's longitudinal study to underpin Australia's medical cannabis boom

Medicinal cannabis use is booming in Australia. Hundreds of thousands of people have accessed the treatment since it was legalized in 2016, with the most significant increase in uptake occurring in the last 18 months, according to the Therapeutic Goods Administration (TGA).

Swinburne's Dr. Thomas Arkell, who also contributed to the paper, stresses the importance of rigorous scientific research to support this increase in medicinal cannabis prescriptions.

Dr. Arkell is currently leading a major longitudinal study at Swinburne investigating the cognitive and health effects of medical cannabis for chronic pain, which is notoriously difficult to treat and is one of the main reasons people are prescribed medical cannabis.

"People with chronic pain often say that medical cannabis has a positive impact on their everyday life and helps them to function normally, but we really need the clinical evidence to support this," Dr. Arkell said. "We are specifically focusing on people with chronic pain who have never used cannabis before, and we're looking at how medical cannabis impacts quality of life and everyday activities, such as driving, over a period of 12 weeks."

In all jurisdictions except for Tasmania, patients who are prescribed medical cannabis containing THC are prohibited from driving, underscoring the relevance of this research in shaping future policies and guidelines for medical cannabis use.