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Previously published on hightimes.com

Previously in “The Chemistry of CBD,” we looked at the subtle changes in the structure of CBD versus that of THC and the potential differences in the resulting conformation of cannabinoid receptor-1 (CB1).

We discussed how minuscule changes can have large multiplicative effects down the biological stream. As with all things in this world, structure determines function. The structure of the molecule determines how it binds to the protein, the movement of the protein determines the resulting cellular action and the structure of neuronal networks determines our physical behaviors which can be measured through science!

A claim that was made in the preceding article posed that CBD has the opposite effects of THC.

There have been a few studies that look at the differences in behavior, as well as the effect of CBD on the behaviors elicited by THC. One study in particular took advantage of a technique known as functional magnetic resonance imaging (fMRI).

You may have heard of an MRI, an imaging technique that uses large magnets to observe the water in our bodies, allowing doctors to see inside us. The only difference between an MRI and an fMRI is that the latter provides a movie, or changes in function over time. The fMRIs allow us to visualize parts of the brain that are activated or inhibited, the active portion of the brain lights up on the monitor. Researchers can then introduce drugs and look at changes of brain activity in real time!

In addition to fMRI experiments, participants in the study were subjected to a series of psychological experiments that are meant to test four areas of cognition associated with smoking marijuana: “verbal memory, response inhibition, sensory processing and emotional processing.” These psychological tests have been developed over the past few decades and allow us to objectively measure changes in behavior with response to a stimulus (in our case, cannabis).

First the researches, lead by Dr. Sagnik Bhattacharyya, wanted to assess the behavioral differences caused by both THC and CBD. The tests were done using capsules containing: 10 mg THC, 600 mg CBD and flour (placebo). The placebo is used to get a baseline, a control to ensure that the changes in behavior they see are actually due to the drug administered.

The drugs were introduced in a semi-random distribution, via a double-blind study. A double-blind study ensures that no one is aware which is which drug, or placebo. The results from all three psychological exams—VAMS, STAI and PANSS—were in complete agreement! CBD elicited responses that are, for all intents and purposes, identical to the placebo. This shows that CBD has no effect on our behavior, further supporting that it does not get us high.

All three test did, however, show that THC changes our behavior, but of course, this was known.

Finally, the experimenters wanted to know what was happening in the brain; this was done by fMRI.

Similar to the psychological studies, the researchers used a placebo to obtain a baseline, or standard behavior of a non-intoxicated person. When the researchers observed six regions of the brain affected by cannabis, they noticed something interesting. CBD affected all of the same areas as THC, however, it had a complete opposite effect!

For example, THC alone had decreased activity in the occipital lobe (muscle memory) compared to the placebo.CBD, however, increased the activity in the occipital lobe.

It is interesting to see how two molecules with nearly identical structures, which activate the same receptor, have such distinctive opposing effects.

Now, the researchers made sure to note that there are potentially other reasons that CBD has different effects on our behavior that were not looked at in this study. But there are two certainties that can be taken from this. One, CBD alone will not get you high. Two, CBD quite literally has the opposite effect of THC on the brain.

Perhaps, there is a balance for a reason. Tune in next time for a further look into the interactions of the two primary components of cannabis!