CBD is known to affect brain serotonin receptors when ingested in high doses, an action partly responsible for the molecule’s anti-anxiety effects. Additionally, CBD can work as a reuptake inhibitor  in the brain, allowing it to raise and maintain high levels of anandamide, an endocannabinoid that is molecularly similar to THC. CBD also inhibits the reuptake of adenosine, increasing levels of the molecule in the brain and contributing to further anti-anxiety effects.
Cannabis is an herb that is most well-known for its psychoactive effects. However, the plant is rich is many different molecules, and the vast majority of them don’t elicit psychoactive effects. THC is the primary cannabinoid within many strains, and produces a psychoactive high by interfacing with CB1 receptors of the endocannabinoid system. This psychoactive effect induces feelings of euphoria and creativity, along with drowsiness, sedation, and even panic and anxiety at higher doses. THC has been found to impair judgement, motor coordination, and reaction time. For this reason, many countries forbid drivers to operate a vehicle under the influence due to the potential danger this poses.
CBD is classed as non-psychoactive. However, the molecule can subtly influence mental state. What’s more accurate to say, as articulated by cannabis research pioneer Dr. Ethan Russo, is that CBD is non-intoxicating. THC achieves its psychoactive states by binding to CB1 receptors sites within the central nervous system. These receptors make up part of the endocannabinoid system, a body-wide system of receptors found on the membranes of many different cell types. CBD exerts many of its effects by interacting with the endocannabinoid system, yet in a more indirect manner.
CBD AND THE BRAIN
So, we’ve pretty much given CBD the clear when it comes to driving safety, but then the law comes in and complicates things. Many CBD oils contain small amounts of THC, with many European countries allowing legal trace amounts of between 0.2–0.6% of the cannabinoid. These amounts are so small that they are not likely to produce any intoxicating effect, unless the oil is consumed in vast quantities. Even in this event, the sedation of a high CBD dose will probably be the primary effect here.
CBD isn’t directly psychoactive like its cannabinoid cousin THC. However, it can impact mood and possibly alertness by catalysing alterations in brain chemistry.
Reported side effects  include low blood pressure, lightheadedness, and drowsiness. For these reasons, it is best to become accustomed to how CBD affects you on an individual level before taking it and going for a drive. If the molecule produces any of these side effects, then it’s probably best not to expose yourself to the roads. Instead, talk to your doctor and discuss why these effects are happening. It might just involve modifying the dosage.
Here’s everything you need to know.
Unlike THC, CBD is a non-psychoactive compound, meaning it should have no effect on the users cognitive functions, and will not, therefore, impair their ability to drive.
What Is CBD Oil?
Derived from cannabis, Cannabidiol, or CBD as it’s more commonly known, is one of over a hundred cannabinoid compounds found in the plant.
There are still, however, many companies who are more interested in profits than high quality products, so we urge users to be careful about where they’re buying CBD oil from.
One side effect that can be caused by taking a high dose of CBD oil, or by taking too much too quickly, is drowsiness. This could obviously be dangerous when driving a vehicle, so again it’s important to be aware of how you are personally reacting to the doses you’re taking, adjusting them accordingly if you do start to experience drowsiness.
It’s increasingly obvious that THC and driving don’t mix: A 2018 research letter published in Jama Internal Medicine revealed that "holiday" 4/20 was linked to a 12 percent increase in fatal car crashes (though that study wasn’t able to control for potential alcohol use). But even among sober drivers, a January 2020 study linked chronic THC use to impaired driving skills — especially in teens who started smoking weed before the age of 16.
The National Highway Traffic Association notes that 795 people died as a result of drowsy driving during 2017, and the CDC estimates that lack of sleep and driving alone was responsible for 72,000 injuries in 2013.
The science of drowsy driving
Tetrahydrocannabinol (THC) is the chemical that’s responsible for marijuana’s characteristic high. Though cannabidiol (CBD) is also an active ingredient of cannabis, its effects on the brain and body are far different, raging from anti-epileptic qualities to potential anti-anxiety effects.
"There is a lot of misinformation on the internet about how CBD can modulate the effects of THC, and I worry that this information might be passed on to unsuspecting medical cannabis patients and consumers," he says.
"We are also nearing the end of an on-road driving study which is looking at the effects of THC and CBD, both alone and in combination, on real-world driving performance," Arkell says. "So we will have the answer to this very soon!"