What Can Science Tell Us About the Anxiety-Reducing Effects of Cannabidiol

In the past decade, various studies have found that Cannabidiol (CBD), which is a cannabinoid found in cannabis plants, has anxiolytic properties.

The exact mechanism of action that gives CBD its anxiolytic properties isn’t completely clear yet. But it’s thought to be related to its interaction with various receptor systems.

Now:

Even though studies have found CBD to have anti-anxiety properties, this doesn’t automatically mean that CBD can be used as tool for relieving anxiety, let alone treating it.

Although the existing studies look promising, clinical trials that looked at the effects of CBD on anxiety are currently few and far between. 

And even if a CBD-based medicine for anxiety was to come out in the future, it doesn’t mean that commercially produced and sold CBD products get this status as well.

Medicines only get that status because they undergo multiple trials and quality control tests that ensure their safety and efficacy. Commercially sold CBD products are not subjected to such trials and tests. Neither are cannabis strains that have high percentages of CBD subjected to such tests.

That being said, today, you’ll get the current status of CBD as an anxiety-reliever in the scientific literature.

How CBD Works When it Comes to Anxiety

CBD is one of the many cannabinoids that interact with receptors in the endocannabinoid system. 

The endocannabinoid system is a complex cell-signaling network that’s associated with the functioning of:

• The central nervous system;
• Neuronal activity;
• The cardiovascular system.

The endocannabinoid system is related to regulation of a range of functions such as sleep, mood, appetite, memory, reproduction, and fertility.

But CBD interacts with other receptor systems as well. For example, one type of receptor that CBD activates is the 5-HT1a receptor, which is a serotonin-subtype receptor.

The bottom line:

CBD interacts with the human body, its nervous systems and various receptor systems, in many different ways. And CBD’s complex interaction with many different physiological processes in the human body could explain why CBD has been associated with numerous different health benefits.

In the case of anxiety, CBD is thought to exert its anxiety-reducing effects by interacting with CB1 receptors, serotonin receptors, and the amygdala-hippocampal-cortico-striatal circuit in the brain. 

So even CBD’s anxiolytic properties are based on different mechanisms of action. CBD may reduce anxiety in different ways.

Currently, most scientific studies attribute CBD’s anxiolytic properties mostly to its interaction with serotonin receptors. Also referred to as a ‘feel-good neurotransmitter,’ serotonin has a very wide-ranging impact on the body. 

Serotonin neurotransmitters are thought to impact anxiety and mood, with low levels of the neurotransmitter being associated with depression and in some cases, anxiety. 

Most traditional anti-depressant and anti-anxiety medication works by influencing serotonin-levels in the brain.

The Current Status of CBD Research

It’s probably safe to say that when it comes to CBD: 

The hype has far outpaced the science. 

While there are hundreds of studies that indicate CBD may have various health benefits, there are currently only two CBD-containing medicines on the market:

• Epidiolex, which is an oral solution containing CBD for treating seizures, and;
• Sativex, which is a THC- and CBD-containing mouth-spray for spasticity reduction.

As you can see, both of them are not specified as a medicine for treating anxiety.

While various studies (which we’ll talk about next) found that CBD does have an anti-anxiety effect, the consensus is that more research and clinical trials are needed before it can be used as medication. 

High-CBD Cannabis Strains May Reduce Anxiety

While high-THC strains of cannabis have been associated with increased levels of anxiety, strains low on THC and high on CBD have been associated with lower levels of anxiety.

A 2018 study published in the Journal of Affective Disorders found that smoking cannabis was associated with lower levels of self-reported anxiety, stress, and depression. 

Strains that had low THC and high CBD levels were the best for reducing subjective symptoms of depression. Interestingly enough, strains with high THC and low CBD levels had the strongest association with reduced symptoms of self-reported stress. 

Generally, the study participants reported a 50% reduction in depression and a 58% reduction in anxiety. This was only for the short-, and medium-term, however. The researchers also concluded that using cannabis to combat depression in the long term could exacerbate the condition. 

CBD May Reduce Social Anxiety Disorder (SAD)

There are several studies that found CBD to be effective in reducing anxiety in patients with SAD.

For example:

A double-blind study carried out in 2019 at the Primate Research Institute at Kyoto University in Japan indicated found that CBD significantly reduced social anxiety over a 4-week period compared to the teenagers who were given a placebo. 

The study was set up by recruiting thirty-eight 18-19-year-old Japanese teens with SAD and avoidant personality disorder. One group received cannabis oil containing 300mg of CBD daily for 4 weeks, while the other group received a placebo.

To measure anxiety two different questionnaires/scales were used at different times during this 4-week period:

• The Fear of Negative Evaluation Questionnaire and;
• The Liebowitz Social Anxiety Scale.

Although side effects were not measured or researched, both during the study and a brief health check-up several months after the study, none of the participants had significant health complaints.

While these results look promising, Professor Masataka recommended further clinical trials in the conclusion of the study. 

In 2011, a study looked at what kind of effects CBD has on SAD patients that underwent public speaking tests. In total, there were 24 patients, divided into two groups of 12 patients. One group received 600mg of CBD, while the other group received a placebo. The group that was given CBD demonstrated significantly lower levels of anxiety, cognitive impairment and discomfort compared to the placebo group.

Another study done in 2011 found that a dose of 400mg orally administered CBD significantly decreased subjective anxiety in patients with SAD.

Using functional neuroimaging, the researchers found that CBD affects activity in limbic and paralimbic brain areas.

According to the same researchers two plausible hypotheses that may explain CBD’s anxiolytic effects are: 

1. Its activation of 5-HT1a receptors and increasing serotonin neurotransmitters (activity) in the brain;
2. Its disruption of forward intrinsic connectivity between the amygdala and the anterior cingulate.

CBD May Reduce Symptoms of Post-Traumatic Stress Disorder (PTSD)

A few studies looked at the effects of CBD on PTSD found that it may have a useful role in reducing its symptoms.

For example:

A 2018 Brazilian review study that looked at the results of various animal and experimental human studies found that CBD may alter important aspects of aversive memories and block their consolidation. The same study defines PTSD as a poor adaption to a traumatic experience. The researchers hypothesize that CBD may reduce PTSD-related symptoms by interfering with the memory-related aspect of PTSD.

A different study published in 2019 looked at how CBD affects symptoms of PTSD in 11 adult patients. 

The study participants received a daily oral dose of CBD in varying doses over a period of 8 weeks, in addition to routine psychiatric care. By the end of the 8^th week, 10 out of 11 participants experienced fewer and less severe symptoms of PTSD. While it’s unclear whether this reduction in symptoms was related to just the CBD or a combination of CBD and psychiatric care, the researchers concluded that CBD may have a role in reducing symptoms of PTSD.

CBD And Anxiety in Animal Studies

While animal studies are not directly relatable to how CBD affects humans, they can give us clues on CBD’s mechanisms of action and serve as a guide for future studies.

Various studies have found CBD to be effective at reducing anxiety in rodents. The National Institute on Drug Abuse (NIDA), states that: 

“CBD has shown therapeutic efficacy in a range of animal models of anxiety and stress, reducing both behavioral and psychological and physiological (e.g., heart rate) measures of stress and anxiety.” 

For example, a study done in 2016 found that CBD had anxiolytic effects in mice that were subjected to stress before the consumption of CBD. Interestingly enough, the researchers only found CBD to have anxiolytic properties when stress was induced before consumption.

A different 2016 study found that chronic CBD administration had anxiolytic effects in chronically stressed rats. In this study, CBD’s anxiolytic effects were thought to be mediated via hippocampal neurogenesis.

The Way Forward: Human Clinical Trials

While the current scientific data looks promising regarding CBD’s anxiolytic effects, we can’t currently classify CBD as a ‘medicine’ for anxiety. A lot of CBD research is done with animal test subjects. Before we can truly ascertain CBD’s effects on the different types of anxieties, its dose-specific efficacy, what its long-term side effects are, more human clinical trials are needed.

Keep in mind that human studies that found CBD to be effective in reducing anxiety used much higher doses of CBD than what’s found in commercially produced and sold CBD products.

Also keep in mind that FDA tests have found that the chance to buy a mislabeled or contaminated CBD product is significant. That’s why it’s essential that you only buy CBD products that are backed third-party lab-tests reports that show the product’s ingredients and contamination-score.

Whenever you decide to try a commercially produced and sold CBD product, make sure you consult a doctor first, especially if you’re on other medication to prevent potential drug interactions. 

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