A new report published in the journal Cannabis and Cannabinoid Research presents an overview of the clinical findings concerning the effectiveness of cannabidiol (CBD) in the treatment of anxiety. While the report suggests that CBD may offer a safe and effective treatment for anxiety, the authors highlight the need for additional research among the female population.
The research team behind the review, led by Madison Wright, notes that anxiety disorders are the most common mental health disorders worldwide. Despite the pervasiveness of anxiety disorder diagnoses, existing behavioral treatments offer limited effectiveness and the current pharmacological treatments carry unwanted negative consequences.
A growing research trend has focused on the anti-anxiety properties of cannabidiol (CBD) — a compound found in the Cannabis plant. Unlike tetrahydrocannabinol (THC), CBD does not produce a “high”, and studies have yet to uncover any evidence of abuse or dependence in humans.
“Anxiety disorders are highly prevalent worldwide and treatment options tend to have adverse side effects and the majority of patients do not achieve complete remission,” explained Wright, a doctoral student affiliated with the Centre for Addiction and Mental Health and the University of Toronto.
“Following the recent push to legalize cannabis in many jurisdictions, CBD has gained a lot of attention from the public and scientific community for its potential therapeutic properties. Given the data demonstrating that CBD is well tolerated and demonstrates little potential for abuse or dependence in humans, we were interested in reviewing the animal and human literature on its use as a treatment option for anxiety disorders.”
Wright and her colleagues reviewed the current findings from both pre-clinical and clinical trials to shed light on the potential role of CBD in the treatment of anxiety.
First, findings from pre-clinical animal studies show that low to medium doses of CBD produce anxiety-reducing effects, while high doses increase anxiety. Animal research also offers evidence that the anxiety-relieving effects of CBD involve the serotonin receptor 5-HT1A. While on the whole, this research shows compelling support for CBD as an anxiety treatment, the researchers note that these studies have only been conducted among male animals.
Next, clinical studies among patients with social anxiety disorder have found anxiety-reducing effects with single doses of either 400 or 600 mg of CBD. During a public speaking simulation task, these doses were found to lower anxiety symptoms, reduce cognitive impairment, and reduce discomfort associated with one’s speech performance. A collection of brain imaging studies additionally revealed that CBD intake alters blood flow in the amygdala, hippocampus, hypothalamus, and cingulate cortex — four brain structures implicated in anxiety.
“The main takeaway from this review is that early research indicates that CBD may reduce anxiety in healthy volunteers,” Wright explained. “The results from studies in animals are promising, suggesting that CBD may reduce anxiety, stress, panic and compulsive-like behaviors.”
“Preliminary evidence from human studies demonstrates that CBD may reduce anxiety in healthy participants and patients with social anxiety disorder. It is important to emphasize that this data is preliminary and more research is required.”
“There are still many questions that need to be addressed and rigorously studied,” Wright said. “The only human studies examining CBD as a treatment for anxiety have been conducted in patients with social anxiety disorder, therefore, research is needed in patients with other anxiety disorders, such as generalized-anxiety disorder and panic disorder. Secondly, much remains unknown about the use of CBD as a treatment for anxiety, such as the most effective route of administration, appropriate doses to be used, and its long-term safety and efficacy.”
While reviewing these findings, Wright and her colleagues also pinpointed another important issue. Although males and females appear to experience anxiety differently, no clinical trials have examined sex differences in the anxiolytic effects of CBD. Most studies have examined male participants, but evidence suggests that women tend to experience worse symptoms and a higher likelihood of having an additional diagnosis. Males, on the other hand, are more likely to experience anxiety alongside alcohol and substance abuse.
“The rates of anxiety disorders are nearly doubled in females compared to males, there are differing anxiety-related symptoms and responses to psychotropic medications between the sexes, and CBD has different effects on the body in males and females,” Wright explained. “Therefore, it is important that future research examines sex and gender differences in the utility of CBD as a potential treatment for anxiety disorders.”
The researchers noted that additional trials will be important to examine the outcomes of CBD among patients with other anxiety-related disorders, such as general anxiety disorder, obsessive-compulsive disorder, and posttraumatic stress disorder. They also suggest that future studies should explore the optimal dose and administration route for CBD and assess its safety in the long term.
“Although this area of research appears to be promising, it is far too early to unequivocally conclude that CBD can be used to treat anxiety. More research is needed to guide physicians and the public in the safe and effective use of CBD as a treatment for anxiety,” Wright concluded.
The study, “Use of Cannabidiol for the Treatment of Anxiety: A Short Synthesis of Pre-Clinical and Clinical Evidence”, was authored by Madison Wright, Patricia Di Ciano, and Bruna Brands.
