One of the most popular therapeutic applications of CBD-rich products is for the treatment of mood disorders such as anxiety and depression. So how does CBD relieve the symptoms of these debilitating conditions? This is what you need to know, but first, get some context on how the brain works here.
What is Anxiety?
Anxiety is a natural healthy feeling. It is our evolutionary defense system. The hypothalamus is the part of the brain that produces emotional responses to sensory stimuli, and it has different layers that control different emotions. All of the senses except for smell travel through this part of the brain before they enter the cerebrum, which is the center of perception and consciousness.
The hypothalamus receives information before we are consciously aware of it, so the emotions it produces are based off of memories rather than logical cognitive responses. Whenever a certain stimulus is associated with a negative memory, part of the hypothalamus becomes active producing feelings of fear and apprehension. When the stressful situation is resolved, serotonin is released making that area become less active, producing feelings of relief and happiness.
In people with anxiety disorder, there is a shortage of serotonin in the brain. This causes the part of the hypothalamus that regulates fear to become hyperactive. When there would normally be a balance of emotions, there is instead an anonymous fear that seems to have no root cause.
CBD’s anxiolytic action via cannabinoid receptors
CB1 receptors are the most abundant receptors in the human brain. They are present in nearly every area of the brain, and they control the rate that neurotransmitters flow into and out of cells, which is how they relay their messages. The power of CBD to relieve anxiety, PTSD, and so many other conditions is possible because these receptors are present in so many different brain areas.
In most brain cells, CBD’s effect on CB1 receptors provokes transport proteins to carry neurotransmitters into and out of the cell more quickly. By allowing neurotransmitters to move more freely throughout the cell, they get degraded more quickly. This triggers a positive feedback mechanism that results in an increase of their production. By energizing this circuit, CBD makes an imbalance of these chemicals less likely.
CBD is an agonist of serotonin 5-HT1a receptors
As we discuss earlier in this series, many of the therapeutic effects of CBD are mediated by serotonin receptors. Serotonin plays a large role in satiation and mood. Serotonin controls mood by inhibiting (or not inhibiting) the part of the brain responsible for fear and fight-or-flight responses. When this part of the brain is active, you feel anxiety. When serotonin is present, it decreases the activity of this part of the brain, producing feelings of tranquility. CBD has the same exact chemical effect on these receptors as serotonin, but doesn’t get degraded by the brain nearly as quickly.
A primary component of clinical anxiety is that the body doesn’t produce enough serotonin, so the alarm center of the brain becomes hyperactive, causing unfounded anxiety and discomfort for no apparent reason. Because CBD mimics the effect of serotonin as a partial agonist of 5-HT1a receptors, it can replace the missing serotonin and inhibit the brain’s center for fear and discomfort, reducing feelings of anxiety and stress. And don’t forget, it promotes the production of serotonin through its action on the cannabinoid receptors at the same time.
Other mechanisms of action
We are still beginning to understand the full potential of CBD for brain health. In addition to cannabinoid and serotonin receptors, it blocks the reuptake of adenosine, which is the opposite of how caffeine works. It also binds to vanilloid receptors, which mediate pain signals, and reduces the excitation produced by painful stimuli. CBD promotes general balance among the systems of the brain and as we learn more about it, more people can be helped.