Plenty of human and animal studies have shown that CBD has an anxiolytic effect on the body. This means CBD can lower anxiety, but the cutting edge of CBD research is in how it works in the brain. Anxiolytic drugs act as minor tranquilizers in the body because they target chemical messengers in the brain and reduce unnecessary stress reactions (such as a faster heart rate or the “fight or flight” response). The anxiolytic properties of cannabidiol are still new to scientists, but there is evidence that CBD works by targeting the limbic and paralimbic systems in the brain to naturally reduce anxiety. For these types of pharmacological studies, neuroscientists look at regional cerebral blood flow through neuroimaging.
Effects of CBD on the Brain
Measuring Brain Activity
Neuroimaging, or brain scanning, is a fairly new method of study that utilizes various techniques to measure the structure, function, or pharmacology of the brain. The most common types of brain scans are EEG, PET, MRI, and fMRI. These types of brain imaging use various waves, special radioactive dyes, electrodes, and other scanning technology to get pictures of the brain and how it’s working.
Neuroimaging can be divided into two general categories:
- Structural imaging. Structural imaging is used to assess physical damage or abnormalities in the brain like tumors and head injuries.
- Functional imaging. Functional imaging, which lights up active parts of the brain, measures everything else: metabolic diseases as well as neurological activity.
EEGs & PETs
EEGs test the electrical activity in the brain using small metal disks called electrodes that attach to the scalp to measure the electrical impulses in the brain. Safe and completely painless, EEGs can measure brain abnormalities and disorders, but can’t detect mental illness or intelligence. EEGs can diagnose and treat dementia, sleep disorders, head injuries, brain tumors, and epilepsy. EEGs can also be used on coma patients because they level the general activity of the brain; but they are also used to make sure the right level of anesthesia is given to people with medically induced comas and to measure brain activity in people in persistent comas.
PET scans show how tissues and organs are functioning in general, and specifically the brain. PET scans use a radioactive drug to detect this activity and can detect diseases before they show up on other imaging tests. When the radioactive drug is ingested either by being injected, swallowed, or inhaled, it shows up on the scan as bright spots. PET scans are great in evaluating or discovering cancers, heart disease, and brain disorders. They can be useful to researchers because they show exactly what parts of the brain are working.
MRIs & fMRIs
MRIs use radio waves, a computer, and a magnetic field to generate a detailed picture of the brain. MRIs are clearer and more detailed than most of the other imaging methods. Because this method doesn’t use radiation, it may require an injection of gadolinium to highlight the parts of the brain being observed. MRI is the most sensitive imaging test for the brain that’s routinely used. MRIs can detect infections, the causes of epilepsy, brain tumors, chronic conditions like multiple sclerosis, and many other things.
Functional magnetic resonance imaging (fMRI) measures the metabolic changes that happen in the brain over time. This test is very useful because it allows observation of the brain while it’s functioning. That’s invaluable for medical cannabis and CBD researchers. fMRIs can be used to determine brain anatomy and the effects of stroke or disease, or to detect things that can’t be found with other techniques. With a technique called brain mapping, fMRIs can determine exactly which part of the brain is handling functions such as thoughts and speech. This is what scientists use for studying the effect of drugs and chemicals on the brain.
CBD and Brain Blood Flow
Using functional neuroimaging, a new scientific CBD study aims to see the effects of cannabidiol on the brain. Scientists measured the regional cerebral blood flow in healthy male volunteers with and without a dose of CBD. Subjects were divided into two groups: a placebo group and a CBD group. Scientists gave half of the men CBD (400mg) and the other half a placebo. Two weeks later, the groups switched and took the other. To prevent false results because of the placebo effect, neither the test subjects nor the observers knew which drug was administered to which subject.
After this double-blind study, they tested the brains of the subjects to see the activity in the brain, where that activity was happening, and overall blood-flow in the brain. This showed the research scientists what parts of the brain were being affected by the CBD, as well as how the overall brain activity was affected by the drug.
CBD Study Conclusions
In both groups, CBD showed an anxiolytic effect on the brain. Neuroimaging scans revealed an overall decrease in anxiety and an increase in mental sedation. The placebo didn’t produce any changes. Scans also showed an increase in activity in two brain areas: the amygdala-hippocampal complex, which affects emotion and memory; and the posterior cingulate gyrus, which controls both pain and working memory functions. There was also more activity around the parahippocampal gyrus, which controls memory retrieval. Most of these parts of the brain are part of the limbic system, which in general controls memory, emotions, and our body’s level of excitement (heart rate, etc). The findings offer more evidence of CBD having anti-anxiety properties through action in the limbic and paralimbic brain areas.
Implications for CBD Treatments
This study taught scientists some important things about how CBD works in the brain, and specifically how it can help calm anxiety. Other studies have shown that taking CBD before a stressful event can help Social Anxiety Disorder, and CBD also calms the brain in general. Even if you aren’t officially diagnosed with an anxiety disorder, CBD helps your brain function more efficiently no matter what. So that little bit of anxiety we all face? Scientists say CBD hemp oil can help.