As many as 35 per cent of all drivers injured or killed on Australian roads test positive to one or more psychoactive substance. Cannabinoids such as delta-9-tetrahydroannabinol (THC) are the most frequently detected substances among affected drivers. Cannabis use results in slowed reaction time and concurrent increased brake time, reduced memory capacities, inappropriate signalling, increased lane deviation and reduced attention abilities, all of which translates to a higher overall accident risk compared to unimpaired drivers. 

Changes in government legislation has allowed medicinal cannabis to be prescribed to patients. As such there is a growing industry in terms of the development of new compounds containing different cannabinoids. Most medicines contain either the cannabinoids THC or cannabidiol (CBD). 

Despite the interest in these compounds there is a lack of research on their effects across a wide range of psychological and social outcomes. THC is known to cause driving impairment, but little is known about the effects of other cannabinoids such as CBD in terms of cognition and driving, although there is some evidence that CBD causes changes in some subjective mood states. As the number of compounds containing CBD increase and become available it is vital that clinical trials are conducted to determine whether medicinal cannabis compounds such as CBD impair driving and cognitive function.

About this study

This study will:

  • assess whether a high CBD/low THC medicinal cannabis oil product [CannEpil. 20:1 cannabidiol (CBD) to (-) -trans-Δ9-tetrahydrocannabinol (THC)] causes driving impairment using a high-fidelity driving simulator when compared to a placebo. 
  • evaluate whether the amount of THC in saliva is under the threshold of currently used road-side saliva tests used by the Victoria Police to detect the presence of low levels of THC in the active drug condition 
  • investigate the neurocognitive effect of orally administered CannEpil versus placebo 
  • investigate the subjective mood, sedation and drowsiness effects of CannEpil versus placebo.

Study progress

This trial has been approved by the Swinburne University Human Research Ethics Committee and will begin recruitment following easing of COVID-19 restrictions. 

For further enquiries

Ms Brooke Manning

Medicinal Cannabis Research Collaboration

+61 3 9214 5483

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Our researchers are committed to the highest ethical, professional and scholarly standards. All our studies conform to the Australian Code for the Responsible Conduct of Research, Good Clinical Practice and the National Statement on Ethical Conduct in Human Research.

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