The reactions between receptors in the endocannabinoid system and cannabinoids can vastly differ on just the tiniest of structural changes, hence why CBD and THC have such contrasting effects despite their similar compositions. The behavior of the protein (receptor) is as influential in the overall reaction as the structure of the cannabinoid.
Let’s find out more about the supposition that CBD and THC have opposite reactions in the body.
Scientists have researched the behavior of both CBD and THC, and also investigated how CBD alters the effects of THC – functional magnetic resonance imaging (fMRI) has proven a game-changer in helping us learn more about these reactions.
An fMRI is essentially an MRI, but in video format. MRIs enable doctors to see inside us by surveying our body’s waters using magnets. The movie from an fMRI, allows researchers to study changes in real-time, specifically determining which parts of the brain are activated or stifled from the introduction of various compounds, like CBD and THC.
Doctors also have psychological tests that they can carry out on participants, to study cognitive changes from smoking cannabis products. These may include alterations to sensory and emotional processing, response inhibition and verbal memory. The tests have been carefully fine-tuned over several decades to ensure that any changes are solely down to the marijuana (or any stimulus being investigated) and no other factors.
Dr Sagnik Bhattacharyya and his research team devised a test involving CBD, THC and a placebo (flour). The placebo was used to provide a baseline for the scientists, so that they could tell exactly which reactions were down to the cannabinoids. They used capsules containing 10mg and 600mg of THC and CBD respectively for the experiment.
Standard double-blind testing and semi-random distribution was used for the experiment, to guarantee that participants had no way of working out whether THC, CBD or flour was being administered.
Interestingly, all of the psychological testing conducted on the participants produced the same result, and one that CBD advocates were hoping for: that the cannabinoid does not affect cognitive functions in any way – the responses were exactly the same as the placebo flour. Therefore, scientists could confidently conclude that CBD isn’t psychoactive and cannot get the user high. Expectedly, the THC testing did elicit changes in cognitive behavior – but we were already well aware of THC’s psychoactive properties.
The researchers also used the testing opportunity to study how the brain responded to the cannabinoids and placebo.
They found that six parts of the brain were affected by marijuana, and that THC and CBD were activating those same six parts. What the scientists hadn’t bargained for, however, was that their effects would be totally opposite. Take the ocipital lobe, which controls muscle memory: it was inhibited by THC yet activated by CBD.
The researchers did leave a disclaimer that the changes in behavior between the cannabinoids may not necessarily be just down to the molecular structure of the two, and that further experimentation would be required to determine whether there are other contributing factors. But they did conclude – with certainty – that CBD cannot get you high and that cannabidiol affects the brain (in the six activated areas) completely differently to THC.
Now, it’s up to Bhattacharyya and co to establish precisely why these reactions occur.