OBJECTIVE: To provide an overview and identify the present landscape of hemp research topics, trends, and gaps.
METHODS: A systematic search and analysis strategy according to the preferred reporting items for systematic review and meta-analysis-ScR (PRISMA-ScR) checklist on electronic databases including MEDLINE, OVID (OVFT, APC Journal Club, EBM Reviews), Cochrane Library Central and Clinicaltrials.gov was conducted to include and analyse hemp research articles from 2009 to 2019.
RESULTS: 65 primary articles (18 clinical, 47 pre-clinical) were reviewed. Several randomised controlled trials showed hempseed pills (in Traditional Chinese Medicine formulation MaZiRenWan) improving spontaneous bowel movement in functional constipation. There was also evidence suggesting benefits in cannabis dependence, epilepsy, and anxiety disorders. Pre-clinically, hemp derivatives showed potential anti-oxidative, anti-hypertensive, anti-inflammatory, anti-diabetic, anti-neuroinflammatory, anti-arthritic, anti-acne, and anti-microbial activities. Renal protective effects and estrogenic properties were also exhibited in vitro.
CONCLUSION: Current evidence on hemp-specific interventions are still preliminary, with limited high quality clinical evidence for any specific therapeutic indication. This is mainly due to the wide variation in test item formulation, as the multiple variants of this plant differ in their phytochemical and bioactive compounds. Future empirical research should focus on standardising the hemp plant for pharmaceutical use, and uniformity in experimental designs to strengthen the premise of using hemp in medicine.
RECENT FINDINGS: The systematic review of the literature on decriminalization resulted in seven articles that discuss decriminalization as compared with 57 published articles on legalization. Decriminalization of drug use did not have an effect on the age of onset of drug use and the prices of drugs did not decrease after the implementation of drug decriminalization. Policy-based studies on decriminalization suggest shifting from criminal sanctions to a public health approach, which was endorsed by the United Nations (UN) that viewed drug addiction as a preventable and treatable health disorder. One study preferred decriminalization only for cannabis and cautioned against regulating cannabis like alcohol. Another study indicated that general medical practitioners in Ireland did not favour the decriminalization of cannabis.
SUMMARY: Scientific evidence supporting drug addiction as a health disorder and the endorsement by the UN strengthen the case for decriminalization. However, studies reporting on the positive outcomes of decriminalization remain scarce. The evidence needs to be more widespread in order to support the case for decriminalization. Furthermore, the endorsement by the UN needs to be acted upon by individual member states.