Everybody wants to draw hard and fast conclusion about cannabis based on the information they find in the media, however most of that information is exaggerated at best. The average person sees an unsourced article on Facebook, Buzzfeed, or Twitter and takes it for what it is without a second thought. Even the scientific articles, the media you are supposed to be able to trust, have huge flaws when it comes to the methodology behind the research. Here, I summarize the three biggest problems with past cannabis research:
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1. CB1 Receptor Agonists: Instead of actually using cannabis in past preclinical research, most studies used CB1 receptor agonists (1). CB1 receptors are the receptors that bind delta-9-tetrahydrocannabinol (THC), which is the psychoactive component of cannabis that is responsible for the high. However, instead of using cannabis and/or THC in research, a similar molecule called a CB1 agonist is used. This is problematic for two reasons: 1. The research doesn’t generate blood-THC levels similar to those in humans who use cannabis (1), and 2. Cannabis is more than just THC (1). There are hundreds of other compounds in the cannabis plant (2) that might have an effect on humans, so to neglect them in research creates a huge translational gap.
2. Route of Administration: Of the Canadian people who consume cannabis, 74% of users smoke cannabis flower and 22% use cannabis vapour (3). However, in the past, most research has used injections as the route of administration (1). This is extremely flawed. How many people do you know who shoot up cannabis? Also, cannabis accesses your brain differently depending on how you consume it. If you inhale it, it reaches your lungs and then is quickly carried from the alveoli on the surface of the lungs to your brain (4). If it is injected, it takes longer as it has to travel through your bloodstream to your lungs and then to your brain. If it is ingested, it takes even longer because it has to be metabolized by your stomach and liver before it can enter your bloodstream and reach your brain (4). Route of administration makes a HUGE difference, so research should reflect how humans consume.
3. Dosage of Use; Again, preclinical research with rodents has failed to control for variables that are essential when it comes to being representative of the human population. When THC is used as the administered drug, the dosage is often ridiculously higher than what it would be in humans (1). When you combine this with poor control for the frequency of use in a lot of past research (1), you end up with results that are completely irrelevant to human populations.
Cannabis is a hot topic in neuroscience research today, but until more control is used in rodent studies, we will not be able to progress with clinical research and changes to public policy surrounding cannabis use. Luckily, these issues are becoming apparent to the science community, and the future of cannabis research seems to be heading in the right direction. Remember to always practice good science neurds!!
- Jessica
Sources
1. McLaughlin RJ (2018). Neuropsychopharmacology 43, 213.
2. Atakan Z (2012). Therapeutic advances in psychopharmacology 2, 241-54.
3. Canadian Cannabis Survey (2020).
4. Lucas CJ, Galettis P, Schneider J (2018). British journal of clinical pharmacology
84, 2477-82.