From: hubermanlab
In the realm of cannabis research, two compounds consistently stand out for their unique properties and effects: THC (tetrahydrocannabinol) and CBD (cannabidiol). Both are cannabinoids found in the cannabis plant, but they exhibit distinct biological mechanisms and subjective effects in users. In a recent discussion with Dr. Matthew Hill, a professor at the University of Calgary specializing in cannabis research, we explored these differences in detail.
## Biological Mechanisms
### THC: The Psychoactive Agent
THC is well-known for its psychoactive effects, primarily due to its interaction with the CB1 receptors located throughout the brain. THC is a high-affinity, low-efficacy partial agonist of the CB1 receptor, which means it binds easily but does not fully activate the receptor compared to endogenous cannabinoids like 2-AG (2-arachidonoylglycerol) <a class="yt-timestamp" data-t="00:15:56">[00:15:56]</a>. This results in the intoxicating "high" associated with cannabis use. THC's effects include changes in mood, perception, and psychomotor control, often described as Euphoria or altered time perception [[neuroscience_of_perception_and_time | altered time perception]] <a class="yt-timestamp" data-t="00:12:15">[00:12:15]</a>.
### CBD: The Non-Intoxicating Compound
In contrast, CBD does not bind directly to CB1 receptors and is often referred to as non-intoxicating. Current research indicates that CBD may act as a negative allosteric modulator of the CB1 receptor, potentially dampening the psychoactive effects of THC by altering receptor shape and function. Additionally, CBD is thought to inhibit adenosine uptake, which might contribute to its calming effects [[role_of_emotions_and_the_nervous_system | calming effects]]; however, its exact mechanisms remain less well-characterized compared to THC <a class="yt-timestamp" data-t="03:04:09">[03:04:09]</a>.
## Subjective Effects
### THC: Varied Psychoactive Experiences
Users of THC commonly report a spectrum of psychoactive experiences, from euphoria and laughter to anxiety and paranoia, largely depending on dose and individual sensitivity <a class="yt-timestamp" data-t="02:11:01">[02:11:01]</a>. The onset of effects can be almost immediate when smoked or vaped, with users able to self-regulate intake based on the quick feedback on subjective experience <a class="yt-timestamp" data-t="01:05:29">[01:05:29]</a>.
> [!info] THC and Appetite
>
> One of the well-documented effects of THC is the enhancement of appetite, commonly known as "the munchies." This effect is mediated through the activation of CB1 receptors within key brain regions involved in hunger and reward [[biological_mechanisms_of_hunger_and_satiety | hunger and reward]] <a class="yt-timestamp" data-t="00:36:00">[00:36:00]</a>.
### CBD: Subtle and Non-Euphoric
CBD does not produce the "high" associated with THC, making it an attractive option for those seeking potential therapeutic benefits without psychoactive effects. Users of CBD report benefits such as pain relief and a reduction in anxiety, although clinical data to substantiate some of these claims at typical commercial doses (often very low in concentration) remain sparse. The therapeutic use of CBD is most robustly supported in the treatment of certain types of epilepsy under medical supervision [[cannabis_use_and_its_potential_link_to_psychosis | potential therapeutic benefits]] <a class="yt-timestamp" data-t="03:02:37">[03:02:37]</a>.
### Conclusion
The discussion with Dr. Hill emphasized the nuanced roles of THC and CBD within the endocannabinoid system, highlighting that while both hold significant clinical potential, their mechanisms and effects are distinct. Users and researchers alike must navigate these differences to maximize therapeutic benefits while minimizing potential risks such as intoxication and dependency. As research progresses, further illumination on these cannabinoids will undoubtedly refine their appropriate uses and mechanisms of action.