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

Abstract and Introduction


Purpose of review: Cannabis use for medical purposes has become increasingly common, including as treatment for mental health disorders such as anxiety. Unfortunately, the evidence examining its use in mental health has been slow to evolve, but is emerging. Given the widespread use of cannabis, it is important for both clinicians and those who suffer with anxiety to understand the effects of cannabis on symptoms of anxiety. In this review, we present recent, available evidence from animal models, clinical trials, and survey studies and evaluate the contribution of these studies to the current understanding of the role of cannabis in treating anxiety.

Recent findings: In reviewing recent evidence, we observed significant inconsistencies across findings from preclinical studies. Large-scale surveys suggest that cannabis may be effective in reducing anxiety, however, these results stand in contrast to equivocal findings from clinical trials.

Summary: The literature evaluating the efficacy of cannabis in anxiety disorders is in its infancy. The survey data is generally positive. Although, while some animal studies posit cannabis constituents to have anxiolytic effects, others suggest the opposite or null results. Few new clinical trials have been conducted recently, and the extant trials have significant flaws in methodology. Although anecdotal evidence from survey studies, and a small signal found in animal studies and single-dose clinical trials provide early support that cannabis may be effective for alleviating anxiety, ultimately, the current evidence is equivocal. More high-quality clinical trials must be published before sound conclusions regarding the efficacy of cannabis for treating anxiety can be drawn.


Anxiety disorders are among the most prevalent mental health conditions, affecting 264 million individuals worldwide in 2017,[1] with large-scale general population estimates suggesting 12-month prevalence rates of 18.1%–22.2%.[2,3] Although a wide range of treatments exist for anxiety disorders, only 40%–60% of patients exhibit adequate responsiveness to first-line interventions such as medications and cognitive behavioural therapies,[4] highlighting the need for alternative treatments.

In recent decades, cannabis has become increasingly popular as an alternative treatment for anxiety symptoms and disorders. Many countries have legalized both recreational and medical cannabis, and individuals continue to use cannabis in regions where it remains an illicit substance. Estimates suggest that approximately 5.1% (28 million) of individuals aged 15–64 in the European region used cannabis in 2016.[5] In the last 4 months of 2018, 1.09 million Canadians used cannabis for solely medical purposes whereas another 1.27 million used cannabis both medically and recreationally.[6] The surge in medical cannabis use has propagated research regarding its mechanism of action, safety, and efficacy. Although many patients report using cannabis to treat their anxiety, little evidence supports its efficacy. Nevertheless, anecdotal reports of the success of cannabis in treating anxiety disorders has garnered the attention of researchers and healthcare professionals, as suggested by newly emerging preclinical studies and clinical trials. As such, the goal of the current review is to examine the recent evidence comprised of work in animal models, clinical and nonclinical samples and survey studies, and evaluate its contribution to our understanding of cannabis for treating anxiety.