Review Identifies 140 Controlled Clinical Trials Related to Cannabis

Scientists have conducted over 140 controlled clinical trials since 1975 assessing the safety and efficacy of whole-plant cannabis or specific cannabinoids, according to a new literature review published in the journal Critical Reviews in Plant Sciences.

A pair of German researchers identified 140 clinical trials involving an estimated 8,000 participants. Of these, the largest body of literature focused on the use of cannabis or cannabinoids in the treatment of chronic or neuropathic pain. Authors identified 35 controlled studies, involving 2,046 subjects, assessing the use of marijuana or cannabinoids in pain management. In January, the National Academy of Sciences acknowledged that “conclusive or substantial evidence” exists for cannabis’ efficacy in patients suffering from chronic pain.

Cannabinoids have also been well studied as anti-emetic agents and as appetite stimulants. Researchers identified 43 trials evaluating marijuana or its components for these purposes, involving total 2,498 patients. They also identified an additional 14 trials examining the role of cannabis or cannabis-derived extracts in the treatment of multiple sclerosis.

Researchers also identified several additional trials evaluating the use of cannabis or cannabinoids for Crohn’s disease, Tourette’s syndrome, Parkinson’s disease, glaucoma, epilepsy, and various other indications.

A 2014 study published in the Journal of the American Medical Association reported that new drugs typically gain FDA approval on the basis of one or two pivotal clinical trials.

Full text of the study, “Medicinal uses of marijuana and cannabinoids,” appears online here.