Anxiety-related disorders, including post-traumatic stress disorder (PTSD), generalized anxiety disorder (GAD), panic disorder, and social anxiety disorder, affects the general population with the highest rate of any mental disorder. Anxiety disorders can devastatingly affect patients’ quality of life and the ability to carry out daily activities. Current treatments use a selection or combination of psychotherapy, various serotonin reuptake inhibitors and antidepressants, which have highly variable rates of efficacy and potentially serious adverse effects, some of which may be life-threatening. Alternative pharmacologic solutions with consistent relief and milder side effects are in urgent need and researchers have turned to CBD as a novel solution in treating anxiety disorders.
Various preclinical studies have examined the anxiolytic effects of CBD in animal models. CBD is found to be a potent activator of 5-HT1A receptors, which are the targets of current anxiolytic medications like buspirone for generalized anxiety disorder. It has been observed in several animal models aiming to replicate different anxiety models that CBD produces anxiolytic effects in rats following a bell-shaped dose-response curve, with low to moderate dose producing the most reproducible anxiolytic effects and higher doses produced no significant changes. CBD does not cause anxiety even at high dosages while THC shows a biphasic effect, where low THC dose is anxiolytic and high THC dose is anxiogenic. CBD has been shown to reduce anxiogenic effects caused by high dose of THC.
Several human trials have been conducted to assess the anxiolytic effects of CBD. In a double-blind placebo-controlled study, the effect of a single dose of 300mg CBD was comparable to that of 5mg ipsapirone (an anxiolytic compound) and better than 10mg diazepam (another anxiolytic compound) in terms of reducing the anxiety induced by the Simulated Public Speaking Test (SPST) in 40 healthy volunteers. Another two randomized controlled trails examined the efficacy of CBD on reducing anxiety symptoms in individuals with Social Anxiety Disorder (SAD). In both studies, CBD significantly reduced anxiety, cognitive impairment, and discomfort in speech performance, decreased alert in anticipatory speech, and significantly inhibited the fear of speaking in public when compared to placebo. Recent neuroimaging studies have shown that CBD modulates neuronal activity in limbic and paralimbic areas, including orbitofrontal, cingulate, and medial temporal cortex as well as the insula, which all play a role in regulating emotional response and have been implicated in various anxiety-related disorders.
In general, there is accumulating preclinical and clinical evidence indicating the promise of using CBD as an effective treatment for anxiety-related disorders. However, these studies have relatively small sample size and short study period. More well-designed clinical studies are required to determine whether CBD is a feasible solution for chronic therapy in anxiety-related disorders.
Reference
Fiani, B., Sarhadi, K. J., Soula, M., Zafar, A. & Quadri, S. A. Current application of cannabidiol (CBD) in the management and treatment of neurological disorders. NEUROL SCI 41, 3085–3098 (2020).
Bonaccorso, S., Ricciardi, A., Zangani, C., Chiappini, S. & Schifano, F. Cannabidiol (CBD) use in psychiatric disorders: A systematic review. NeuroToxicology74, 282–298 (2019). https://pubmed.ncbi.nlm.nih.gov/31412258/
