A systematic review and qualitative exploratory study identifying negative aspects of medical cannabis

Background: The use of cannabis in medical contexts, i.e. 'medicinal cannabis' (MC), has increased in the past decades, globally and in Israel. However, little is known about the consequences of MC use and several concerns have been raised as to the efficacy and safety of MC. In this presentation, I will present two studies aimed at identifying the unique consequences associated with MC use. Methods: In the two phases of this study, we have (a) Systematically reviewed qualitative studies concerning patients' experience with MC use, to gain insight into the unique negative effects of MC. Literature searches were conducted using PubMed, PsycINFO and EMBASE. (b) Performed qualitative interviews with patients using prescribed MC for either chronic pain (N=15) or PTSD (N=10) in order to gain further understanding of the long-term effects of MC use and to explore similarities and differences in narratives emerging from these two patient populations regarding their positive and negative experiences with MC. Results: Eight articles were included in the systematic review and six themes were identified: 'MC prescription'; 'Administrative barriers'; 'Social perception'; 'Using MC to treat multiple conditions'; 'Adverse effects'; and  'Dependence or addiction'. These were grouped into two meta-themes: 'Administrative and social aspects of MC use' and 'Experiences of the effects of MC'. Content analysis of the qualitative interviews identified four meta themes: 'Positive effects'; 'Idealization'; 'Ambivalence'; and 'Negative effects'. Conclusion: Considering the growing endorsement of MC laws across the globe, our findings call for consideration of the negative physiological, social, emotional and functional consequences associated with MC misuse. Professionals working with patients prescribed MC should consider the underlying diagnosis, MC adverse effects and MC misuse while interacting with patients. Future studies should empirically explore the different outcomes of MC treatment, including treatment adherence, misuse and problematic use.