Safety of vaped cannabis: Pharmacokinetic differences between cannabis smoking and liquid vaping: Examining the effects of cannabis on cognition

Growing evidence suggests that cannabis use is associated with adverse mental health outcomes, including impaired cognition during acute exposure. New methods of consuming cannabis, such as vaping, are more readily available with legalization. However, recent outbreaks of respiratory illness associated with consumption of mostly unregulated THC-containing vaping products has called into question the safety of this mode of administration. This study evaluated the effects of vaping cannabis compared to smoked dried cannabis, with a primary focus on acute cognitive impairment, which could potentially contribute to mental health issues. We also compared the physiological, pulmonary and toxicity effects of smoked cannabis and vaped cannabis.

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Eligible participants were invited to the lab and were permitted to smoke or vape their usual cannabis using their usual methods. Cognitive measures were taken before smoking/vaping cannabis and at two time points after. Pulmonary function was also measured and emissions in the air were evaluated in the room where participants smoked (a) and in the room where they detoxed (b). This study provided valuable insights into the relative safety of different routes of cannabis administration and provided evidence-based data on the safety of vaping cannabis.

This study was novel in that we studied the impact of ecologically valid doses of cannabis on cognition and related measures. Canada is in a unique position to be able to study commercialized cannabis in the lab. In this study we compared the effects of a user’s preferred smoked or vaped cannabis on cognition, pulmonary function and air emissions. We found that cannabis had an impact on cognitive measures using the CANTAB battery of tests; this provides one of the first uses of CANTAB for studying cannabis. Air emissions contained higher levels of THC after smoked cannabis when compared to vaped cannabis.

This study is funded by the EMHSeed opportunity (University of Toronto and CAMH)

The Team
Patricia Di Ciano Chung-Wai Chow Siddhi Patel
Ahmed N. Hassan Amirashkan Askari Danial Behzad
Sergio Rueda Xing Wang
Arthur W.H. Chan Rachel Ortiz