The Role of Cannabis in Treating Anxiety: An Update

Michael Van Ameringen; Jasmine Zhang; Beth Patterson; Jasmine Turna


Curr Opin Psychiatry. 2019;33(1):1-7. 

In This Article


The research surrounding the treatment of anxiety with cannabis is emerging, but is not yet at a stage where any strong conclusions may be drawn. Studies of animal models are promising, signaling an anxiolytic ability of CBD, THC, and other CB1R agonists; however, the mechanisms behind these effects remain equivocal. This mixed literature may be the consequence of variability in critical factors including when and how treatment is administered, dosing, and duration of treatment. These limitations also extend to the oblique evidence drawn from the existing clinical literature, which is routinely criticized by reviews for the high risk of bias and small sample sizes,[18–20] as inadequately powered studies may result in exaggerated significance in treatment effects or lack thereof. Further, results based on nonclinical subjects, or single-dose studies provide oblique evidence, at best, for the therapeutic nature of cannabis for anxiety. The samples that have been examined, either clinical or nonclinical have not been well characterized. These samples may contain individuals who have clinical characteristics and comorbidities that make them less responsive to treatment and therefore may obfuscate the actual treatment effect. In addition, studies of anxiety among other clinical populations may not be generalizable to clinically anxious groups. More specifically, these studies are unable to preclude improvements in anxiety are not simply a consequence of improved symptoms of their primary condition. Results of survey studies generally suggest strong subjectivity in the reported anxiolytic effects of cannabis as these studies include samples of cannabis users, who have likely had largely positive experiences with medical cannabis.[36] Whether these effects hold true in empirical trials has yet to be verified.

Despite the equivocal nature of the literature regarding cannabis' ability as an anxiolytic, survey outcomes suggest that many patients are embracing cannabis as a treatment for their anxiety, which may warrant a more thorough evaluation of this alternative treatment. The landscape of cannabis legalization is rapidly evolving and cannabis is more easily accessible than ever before. It is anticipated that cannabis use in the general population will increase exponentially as more and more jurisdictions allow its use. Further research is critical to reconciling discrepancies between survey outcomes and results from clinical trials so that patients and clinicians can make informed decisions regarding treating their anxiety with cannabis.