CBD vs THC: Effects on the Brain and Mind

How these major cannabinoids influence your gray matter


The popularity of marijuana in recent years is coinciding with an increase in basic cannabis understanding. Simply put, it’s clear that appreciation of this useful and medicinal herb is on the rise.

Just look at the number of people who now use marijuana daily. Folks are coming to terms with the fact that marijuana isn’t an inherently dangerous and harmful substance. They are using it on their own terms, and for their own wellness benefit (even if this just means relaxing after a long day’s work).

Despite this increase in knowledge, however, there is still plenty of confusion out there regarding the biomechanics of cannabis. One of the most important questions people are asking is how cannabinoids in marijuana affect the brain.

In this article, we inspect this topic closely. While we don’t yet fully understand how cannabinoids work within the brain (nor do we understand their precise effects and reactions), we are making headway, and we know more than we ever did before.

How Do Cannabinoids Interact with the Body?

The book is yet to be written on the “physiological machinery” of cannabinoids. In other words, there is little understanding of the mechanisms behind the interaction between cannabinoids and the human body.

We do know, however, that when you consume any cannabinoid (THC, CBD, etc) it breaks down in the liver. We also know a little bit about something called the endocannabinoid system, or ECS.

The ECS is a cellular networking system that runs throughout the human body. It regulates and influences a variety of bodily functions using two primary receptors: CB1 and CB2. The release of cannabinoids in the body triggers these receptors and induces an assortment of internal reactions.

DID YOU KNOW? The body actually produces cannabinoids on its own, without the inclusion of cannabis.

Does everyone have cannabinoid receptors in their body?

This is why cannabis affects our bodies. The molecular structure of our internal cannabinoid receptors allows plant-based cannabinoids to work with on a fundamental, cellular level. However, when most folks consume cannabis, the phytocannabinoids (‘phyto’ means plant-based) end up in higher concentrations than the endocannabinoids. Depending on each individual, this can produce varied effects.

In terms of its role in the body, the ECS is probably responsible for far more than most of us expect. For example, it appears that the inflammation response (wherein the body causes a particular area to enlarge so as to protect it from injury or infection), is controlled by CB2 receptors in the endocannabinoid system.

While it is comforting to know that the body can work with phytocannabinoids like CBD and THC, it is important to remember that these compounds are not exactly the same as our endocannabinoids. They look and interact similarly to the cannabinoids produced in the body, but they still have their differences.

So how do THC and CBD differ in how they interact with the brain? Let’s take a close look…

THC’s Effects on the Brain

THC is the far more well-known component of cannabis. Unfortunately, it frequently associates with negativity as decades of generalizations paint it as an addictive gateway drug. (In terms of side effects, the only real danger of THC is with overuse).

In actual fact, THC is largely harmless. It induces a variety of effects, the most common of which is a psychoactive high. This high is caused by the compound’s interaction with neurotransmitters in the brain. But what actually happens in order to “create” this high?

It’s all about receptors…

The answer lies in the CB1 receptors. As we discuss above, this is one of the two main receptors in the endocannabinoid system. CB1  receptors exist in abundance within the brain, and are know to influence the release of dopamine. This is the neurochemical responsible for the sensation of happiness or joy.

In the absence of phytocannabinoids, CB1 receptors activate thorugh anandamide. This is an endocannabinoid that is made in the ECS when the brain wants to produce a feeling of happiness. In other words, anandamide is present in the CNS when you feel good and are enjoying yourself. It is one of the brain’s “reward molecules,” and is the chief endocannabinoid present when you’re doing things you enjoy.

Anandamide is similar in shape to THC. This enables THC to mimic its effect; when you imbibe THC, your brain’s CB1 receptors associate with the compound to produce feelings of euphoria. Instead of triggering a receptor and then decaying like anandamide, however, THC stays at the CB1 receptor site.

Instead of triggering the receptors and then decaying like anandamide, THC stays at the CB1 receptor site, triggering it repeatedly.

The length of THC’s stay at a receptor site appears to depend largely on its abundance. A study in Brain: A Journal of Neurology found that in addition to THC’s interaction with CB1 receptors to create euphoric sensations, it also inhibits the release of amino acids and monoamine neurotransmitters in the brain.

What does this do?

Even though THC induces happiness (as well as the other effects of “being high”), it can produce anxiety and paranoia in instances of overconsumption. It can also facilitate disruptive psychomotor behaviors (i.e. slowed reaction times). This happens when CB1 receptors remain active for long periods of time.

THC can have effects on other areas in the brain. Within the hippocampus (a section of the brain responsible for memory retention and learning), THC can lead to the degradation of long-term memory acquisition. It can also affect general cognitive function.

Several studies, such as this one published in the American Journal of Drug and Alcohol Abuse, suggest that too much cannabis can lead to long-term cognitive degradation. This degradation is similar in pattern to the neural degradation one experiences with aging.

In other words, if you smoke too much cannabis (especially at a young age), you may lose neurons at a faster rate. Eventually, this can inhibit mental faculties and reduce brain activity.

But what about CBD? How does this lesser-known cannabinoid affect the brain – at least in comparison to THC?

CBD’s Effects on the Brain

CBD, properly known as cannabidiol, affects the brain, and indeed the entire body, quite differently when compared to THC.

Instead of binding with the CB1 receptors and stimulating them over and over again, CBD works in a very different way. Firstly, CBD prefers to link up with the CB2 receptor, rather than the CB1 receptors.

This isn’t to say it is incapable of working with the CB1 receptors, only that it “fits” better there, and thus tends to go there first. However, the way it works with its chosen receptor is quite different altogether when compared to THC.

Rather than binding to the receptors directly and overstimulating them, various studies, like this one by Natalia Battista for the Journal of Frontiers in Behavioral Neuroscience, have found that CBD instead simply works nearby. It stimulates the CB2 receptors not directly, but through blocking the receptors’ direct antagonists.

Essentially, the body’s method of controlling various bodily functions is to send a sort of signal to the relevant receptor, an antagonist that basically tells the receptor to shut off. However, CBD sits there, blocking the antagonist’s path to the receptor, making it so that the receptor is constantly being triggered through its association with CBD.

So what does this mean?

This means that CBD is incapable of creating any kind of psychoactive high, as it doesn’t stimulate either of the CB receptors strongly enough to induce that sensation of feeling high.

Additionally, the effects of CBD tend to be longer-lasting, as it continues to stimulate the CB2 receptor gradually and smoothly, without any of that initial burst of intensity that THC is known for.

However, there is a myriad of other effects that CBD can produce in the brain that THC simply can’t, and this has to do with its ability to act as a neuroprotective agent.

Studies have shown, like this one by Hampson et al. for the Annals of the New York Academy of Sciences, that CBD acts as a guardian for various neurons in the brain, slowing down the rate of neurological decay that overuse of THC can cause.

Additionally, and perhaps even more interestingly, this also applies to diseases that induce neurological decay, such as Parkinson’s disease. By protecting the degradation of neurons within the brain, patients with these conditions report the slower onset of symptoms, resulting in a higher quality of life.

CBD as an epilepsy treatment

Furthermore, CBD is well known as a treatment for epilepsy, and indeed was only recently federally legalized for use in the treatment of a few particularly unpleasant forms of epilepsy, like Dravet syndrome. Though the precise mechanisms still aren’t fully understood, using CBD in combination with the regular epilepsy medication Clobazam massively increases both drugs’ efficacy.

All this combines into a variety of useful potential medical benefits from using CBD, both as a way to induce relaxation and to help treat all manner of bodily injuries, but also tackle some very specific and frightening conditions.

Final Verdict About CBD vs. THC & Their Effects on the Brain and Mind

The difficult thing about trying to compare CBD and THC when discussing their effects on the brain is that they are fundamentally different things.

While they are both cannabinoids, they are also inherently different in their chemical composition and intended use.

While it does appear that CBD works to help counteract some of the more unpleasant side effects associated with using THC, it also works with the body in an entirely different way than THC does.

The important thing to keep in mind is that the best way to experience and enjoy these cannabinoids, and to get the very best health effects possible, is to enjoy them together simply; make sure to use cannabis that contains sufficient quantities of both cannabinoids to enjoy the fullest effect.

A parting word from Dr. Ted Valley:

As a statement of the obvious, we are not recommending the use of illicit substances. However, if you reside in a state that legalizes the medical or recreational use of THC-containing cannabis, the article should serve as a good resource to get you started on your journey.

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