Analysis Finds ‘Few Changes In Cognitive Performance’ Post-Cannabis Use
One of the main talking points used by cannabis opponents is that ‘cannabis is bad for the brain’ and that its use will result in significant declines in cognitive performance. The talking point is often applied to public policies as they pertain to driving under the influence.
A team of researchers affiliated with the University of the Sunshine Coast and the University of Queensland, both in Australia, recently performed an analysis examining cognitive performance after patients have used medical cannabis products. The results of the analysis were posted in the academic journal Drug and Alcohol Review.
“This program of research investigated the acute effects of orally ingested (Study 1) and vaporised (Study 2) cannabis containing delta-9-tetrahydrocannabinol (THC) on cognitive functions relevant for driving in two samples of medicinal cannabis patients (Study 1 N = 41 oral users; Study 2 N = 37 flower users).” the researchers wrote.
“Participants completed counterbalanced baseline (no cannabis) and cannabis consumption (post-cannabis) appointments scheduled approximately 1 week apart. During each session, participants were administered a cognitive battery assessing information processing speed, sustained and divided attention, inhibitory control and mental flexibility. In the post-cannabis condition, the battery was completed 90 min after consuming one dose of cannabis oil (Study 1) or 15 min after vaporising one dose of cannabis flower (Study 2).” the researchers stated about their methodology.
Many jurisdictions where medical cannabis is legal, including Australia, are struggling with how to strike the right balance between keeping people from operating motor vehicles when they are too impaired and not persecuting medical cannabis patients who are not impaired and simply have metabolized THC in their systems.
“In both samples, acute cannabis oil and flower administration did not induce a change in information processing speed, divided and sustained attention, or inhibitory control performance (after excluding participants with a positive drug indication at the start of either session), highlighting the moderating role of tolerance.” the researchers found.
It is worth noting that the population size of this analysis was not large, and further research is needed. However, the results of this analysis in Australia are in line with findings from other studies that have examined medical cannabis use and cognitive performance.
A 2018 meta-analysis conducted in the United Kingdom also found that “the acute effects of single cannabinoid administration are less prominent in regular cannabis users compared to non-regular users” and that “repeated cannabinoid administration more consistently suggest less prominent effects upon repeated exposure.”
In laypeople’s terms, patients who use cannabis more regularly are less likely to be impaired after cannabis consumption compared to infrequent consumers. That is an important distinction because per se cannabis DUI laws are such that they penalize frequent consumers for having built up metabolized THC in their system, even though those consumers are less likely to be impaired at the time of testing.
Conversely, the metabolized THC thresholds of per se cannabis laws often result in infrequent cannabis consumers testing below the THC threshold, even though they are more likely to be impaired after cannabis use. As such, cannabis DUI laws need to be based on sound science, and not arbitrary metabolized THC thresholds that ultimately do not detect true intoxication levels.
