Our findings are in line with a smaller case-series study in Brazil that followed 25 treatment-seeking individuals with problematic crack use who reported using marijuana to reduce cocaine-related craving symptoms. Over a nine-month follow-up period in that study, conducted by Eliseu Labigalini Jr, 68% of participants had stopped using crack.
As in our study, in Brazil cannabis use peaked during the first three months of follow-up, with only occasional use of cannabis reported in the six months after that.
Qualitative studies in Jamaica and Brazil also indicate that crack users frequently self-medicate with cannabis to reduce cravings and other undesirable effects of crack.
Other research has shown that long-term cannabis dependence might increase cocaine cravings and risk of relapse. Rather than contradict findings from Canada, Brazil and Jamaica, these discrepancies suggest that patterns of cannabis use and dependence, and the timing of self-medication with cannabis, may play a role in individual outcomes.
Building on the finding from this preliminary study, the BC Centre on Substance Use is planning more research to confirm whether using cannabis might be an effective strategy for people seeking to reduce their use of crack or other stimulants, either as harm reduction or as treatment.
Canada’s recent move to legalise and regulate marijuana should facilitate this work. For decades, stigma and prohibition have blocked rigorous scientific evaluation of cannabis. Now these obstacles are beginning to disappear, enabling our team to better understand and unlock the therapeutic potential of cannabinoids.
M-J Milloy, is a Research Scientist with the BC Centre on Substance Use and Assistant Professor in the Division of AIDS, UBC Department of Medicine , University of British Columbia and M. Eugenia Socias, Postdoctoral Fellow and clinician-scientist with the BC Centre on Substance Use and UBC Faculty of Medicine, University of British Columbia