Neural basis of anxiolytic effects of cannabidiol (CBD) in generalized social anxiety disorder: a preliminary report.
Cannabis sativa L is a plant that belongs to the family Cannabaceae. It is a family of flowering plants. There are 13 species of Cannabaceae, of which Cannabis sativa L is the documented one.
THC and CBD are two important extracts which are got from this plant.
THC is the short form for tetrahydrocannabinol. Which is the main component in the drug marijuana. Its causes hallucinations and euphoria.
CBD is the short form for cannabidiol. It is the non-hallucinating extract being used in several scientific studies.
What is an Anxiety Disorder?
Anxiety is an emotion felt by all human beings. But in some people, there is intense, excessive and persistent worry and fear about everyday situations.
Such people are said to suffer from a disorder called Social Anxiety Disorder.
They often have repeated episodes of sudden feelings of intense anxiety and fear or terror that reach a peak within minutes. Such episodes are called panic attacks.
These feelings of anxiety are difficult to control.
Anxiety disorders are of two types-
- Social Anxiety Disorder (SAD)
- Generalized Anxiety Disorder (GAD)
- Symptoms of a chronic anxiety disorder include
- Feeling nervous or tense all the time
- Hyperventilation (Rapid breathing)
- Increased Heart Rate
- Insomnia
- Gastrointestinal problems.
What happened in the study
Studies conducted with both humans and animals showed that CBD has anxiolytic properties. Anxiolytic means something that relieves anxiety.
Although, no study till today has been conducted on the effects of CBD on human pathological anxiety, or the brain mechanisms that assist it.
The main purpose of this study was to understand the effect of CBD on the brain mechanisms in patients suffering from generalized social anxiety disorder.
This was to be achieved by using functional neuroimaging. Neuroimaging is nothing but brain imaging. Which is a procedure used to understand the working of the human central nervous system.
Regional cerebral blood flow (rCBF) at rest was measured twice using (99m)Tc-ECD SPECT in 10 treatment-naive patients with social anxiety disorder.
Regional cerebral blood flow (rCBF) is the measure of the blood flow in any specific area of the brain. The rCBF is measured by a procedure called SPECT. SPECT is the acronym for single-photon emission computed tomography. An element from the periodic table called Technetium was used in this procedure. SPECT is a clinical process to measure rCBF.
Treatment-naive means a person who has never received a particular medication for a specific illness ever. (Eg- an AIDS patient who has never received anti-retroviral medication ever)
In the first session, the patients were given a dose of CBD (400 mg) or placebo orally, this was the double-blind procedure. [This means, the medication was exchanged with placebos (and vice versa) without the patient knowing.]
In the second session, the medication was exchanged.
That means, the people given the placebo in the first session were given CBD in the second session, and the patients given CBD in the first session were given placebo in the second session.
Within-subject between-condition rCBF were compared using statistical parametric mapping. “Within-subject” means an experiment in which the same group of subjects serves in more than one treatment.
CBD dosage showed a significant decrease in anxiety, maintaining a p value of less than 0.001 – p value measures the significance of any statistical result.
There was reduced ECD uptake in the left parahippocampal gyrus, hippocampus, and inferior temporal gyrus, maintaining a p value of less than 0.001. There was an increased ECD uptake in the right posterior cingulate gyrus, maintaining a p value of less than 0.001.
The parahippocampal gyrus spreads over a large portion of the temporal lobe of the brain.
The temporal lobe is the area of the brain just near the neck, covering the ear area. The parahippocampal gyrus is located at the junction between brain regions, it is important for the formation of memories.
Hippocampus is the site in the brain’s limbic system where the connection between emotion and memory happens.
The inferior temporal gyrus is essential for visual object recognition in the brain. The cingulate gyrus is suspected to have a role in cognition, though is no direct scientific proof for it.
These results suggest that CBD can actually reduce anxiety in people suffering from social anxiety disorder. This inference is related to its activity in the limbic and paralimbic areas of the brain.
The limbic system is mainly responsible for emotions and formation of memories.
What did the study conclude?
The study results suggest that CBD can help relieve anxiety in people suffering from SAD. It targets the limbic system, hence affecting the amount of emotion felt by a person.
What does this mean?
This could really come as a breath of fresh air to people suffering from GAD or SAD. CBD, being safe and non-psychedelic, helps reduce anxiety by targeting the relevant areas in the brain.
Instead of popping ten pills a day to combat social anxiety, CBD could really change the scene for people suffering from SAD.
Read the research paper here –
https://www.ncbi.nlm.nih.gov/pubmed/20829306