Therapeutic Efficacy of Cannabidiol (CBD): A Review of the Evidence from Clinical Trials and Human Laboratory Studies

Curr Addict Rep. 2020 Sep;7(3):405-412. doi: 10.1007/s40429-020-00326-8. Epub 2020 Jul 25.


Purpose of review: Global policy changes have increased access to products containing cannabidiol (CBD), a primary constituent of hemp and cannabis. The CBD product industry has experienced tremendous growth, in part, because CBD is widely touted as an effective therapeutic for myriad health conditions. However, only 1 CBD product (Epidiolex®) has been approved by the U.S. Food and Drug Administration (FDA) to date. There is substantial interest among consumers and the medical and scientific communities regarding the therapeutic potential of CBD, including for novel indications that are not recognized by the FDA. The purpose of this review was to synthesize available evidence from clinical research regarding the efficacy of CBD as a therapeutic.

Recent findings: Human laboratory studies and clinical trials (e.g., randomized controlled trials and single-arm, open label trials) evaluating the efficacy of CBD as a therapeutic were identified for various medical conditions, including epilepsy, anxiety, pain/inflammation, schizophrenia, various substance use disorders, post-traumatic stress disorder, and others. There is clear evidence supporting the utility of CBD to treat epilepsy. For other health conditions reviewed, evidence was often mixed and/or there was a general lack of well-powered randomized, placebo-controlled studies to draw definitive conclusions.

Summary: Rigorous, controlled evidence for the therapeutic efficacy of CBD is lacking for many health conditions. Possible concerns with the use of CBD as a therapeutic include the potential for adverse effects (e.g., liver toxicity), drug-drug interactions, and lack of sufficient regulatory oversight of retail CBD products.

Keywords: cannabidiol; cannabinoids; cannabis; clinical trials.