Current controversies in medical cannabis: Recent developments in human clinical applications and potential therapeutics

• Published in: Neuropharmacology 2021-06, Vol.191, p.108586-108586, Article 108586
• Main Authors: Schlag, Anne Katrin, O'Sullivan, Saoirse E., Zafar, Rayyan R., Nutt, David J.
• Format: Article
• Language: English
• Subjects: Cannabidiol (CBD); Cannabidiol - therapeutic use; Cannabinoids - therapeutic use; Cannabis; Cannabis-based medicinal products (CBMPs); Dronabinol - therapeutic use; Humans; Medical Marijuana - therapeutic use; Patient reported outcomes (PROs); Real world evidence (RWE); Δ⁹-tetrahydrocannabinol (THC)
• ISSN: 0028-3908; 1873-7064
• DOI: 10.1016/j.neuropharm.2021.108586

Knowledge about the therapeutic potential of medical cannabis has greatly improved over the past decade, with an ever-increasing range of developments in human clinical applications. A growing body of scientific evidence supports the use of medical cannabis products for some therapeutic indications, whilst for others, the evidence base remains disputed. For this narrative review, we incorporate areas where the current evidence base is substantial, such as intractable childhood epilepsy and multiple sclerosis, as well as areas where the evidence is still controversial, such as PTSD and anxiety. We provide a high-level summary of current developments using findings from recent major reviews, as well as real world evidence (RWE), including global database registries and other patient reported outcomes (PROs). On the one hand, our strongest empirical data supports the use of cannabis-based medicinal products (CBMPs) for conditions with relatively small patient numbers. Yet on the other hand, the conditions, where the highest patient numbers present, often have debatable clinical evidence but good RWE, incorporating PROs of 1000s of patients. The discord between PROs and the respective strength of the evidence from randomised controlled trials (RCTs) highlights the urgent need for further research. The scientific literature examining the efficacy of medical cannabis for many conditions is still developing, whilst large numbers of patients globally have been successfully using medical cannabis to treat a broad range of conditions. We conclude on the importance of systematically developing RWE databases to supplement RCTs and to bridge the current evidence gaps. •Improved knowledge about cannabis based medicinal products (CBMPs) is widening the range of human clinical applications.•Some of the conditions for which CBMPs are used are well established by now, while other areas remain controversial.•The strongest empirical data supports the use of CBMPs for conditions with relatively small patient numbers.•The conditions with the highest patient numbers often have debatable clinical evidence but good Real World Evidence (RWE).•Discords between RWE and the strength of evidence from randomised controlled trials (RCTs) highlight the need for further research.