James Siklos-Whillans, Alia Bacchus, Laurie A. Manwell

Published in International Journal of Mental Health and Addiction

March 2020


Cannabis as a harm reduction strategy (HRS) is supported by evidence demonstrating its efficacy for pain relief and as a substitution for alcohol, illicit drugs, and pharmaceuticals. Animal models show cannabinoids reduce the effects of opiate withdrawal, which contribute to drug-seeking behavior. This scoping review assessed cannabis and its extracts as HRS while identifying critical gaps in preclinical and clinical research. Halas et al.’s (British Medical Journal Open, 5, e006643, 2015) five-stage scoping review methodology was used focusing primarily on “harm reduction” and “harm reduction strategies” related to “cannabis” or “marijuana” and its derivatives “THC” and “cannabidiol.” Across 33 countries, 57 articles were identified demonstrating that cannabinoids (i) enhance opioid analgesia while reducing tolerance and dependence, (ii) interrupt dependence on cocaine, alcohol, and nicotine, and (iii) can be vaporized or eaten to reduce harms associated with smoking. Critical gaps in research include (i) discrepancies due to species and route of administration differences and (ii) the legal status of cannabis. Future research on HRS should examine access to cannabis and its extracts, the effects of varying cannabinoid concentrations, limiting selection bias by recruiting more authorized medicinal and recreational cannabis users, and the various methods cannabis is consumed in humans and animal models of drug dependence. 


Open Access


DOI: 10.3390/biom10020279


Siklos-Whillans, J., Bacchus, A., & Manwell, L. A. (2020). A Scoping Review of the Use of Cannabis and Its Extracts as Potential Harm Reduction Strategies: Insights from Preclinical and Clinical Research. International Journal of Mental Health and Addiction, 1-24