What does CBD do to the brain? That's where it, and indeed pretty much any substance at some point, manifest their effects.
All of CBD's effects are heretofore unknown. It isn't entirely known everything that CBD does, and in fact it isn't even entirely clear what it DOES do. At the moment, there are strong theories about what it does do based on the clinical evidence that's been gathered so far.
The scientific literature seems to have formed some early conclusions about its effects, which have been cited over and over, to the point that they can be taken as being the established theories about what CBD does to the brain.
In treating epilepsy - the only treatment for which CBD is FDA-approved - what the medical literature indicates is that CBD forms a protective layer on the brain, almost like a coating that guards against seizure activity.
Seizures are measured by electrical impulses in the brain. The brain test that many people undergo when it comes to a seizure is an EEG or electroencephalograph. A seizure in action is like an electrical storm in a specific part of the brain, which determines the type of seizure that it is.
What was noticed when patients used CBD as part of their epilepsy management regimen was that electrical activity in the parts of the brain where those patients were suffering seizure had less of the bioelectrical activity that induces a seizure.
So it seems that one of the effects that CBD has is something like insulation for the brain, which may be the reason why it is effective at treating or supplementing treatment of various epileptic disorders.
Another way that CBD works in the brain is by acting as a reuptake inhibitor for certain neurotransmitters.
If you don't know what that means, here's the quick version:
The nerves in your brain work by releasing chemicals - neurotransmitters - into the synaptic gap, the space between the ends of two nerves in a chain, along with an electrical impulse. After the electrical impulse has passed, a certain amount of that chemical is absorbed back into the nerves, which is called reuptake. The brain detects the amount of neurotransmitter left over, and takes the action it's programmed to take based on that.
People who have depression have too little serotonin, hence why depression meds are serotonin reuptake inhibitors. People with chronic anxiety usually have too much adrenaline, cortisol or norepinephrine, meaning those conditions have to stimulate reuptake.
Bear in mind that medical science (and science in general) is an evolving, changing body of knowledge. What seems true today is laid waste to in a few years' time. Remember also that CBD research is in its infancy; very little was known about CBD or THC, for that matter, and the effects of these compounds on the brain until more or less the past 20 years. However, these are the effects that researchers are convinced of.
CBD appears to act as a reuptake inhibitor for a few different neurotransmitters, including adenosine - which is part of pain signals to the brain, as well as inflammation - which is part of why CBD has great potential for treating pain and inflammation. Some evidence has also emerged that CBD has some potential as a serotonin reuptake inhibitor.
CBD has also been linked to suppressing activity within the endocannabinoid system, which is why it's believed that CBD is able to counteract the intoxicating effects of THC.
Again, these effects of CBD on the brain have been repeated enough in the medical literature - go check out PubMed, and see for yourself; these theories are cited repeatedly by study after study - that we can take them as being the best guess that medical science has to date.
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