Given the ongoing prescription opioid use disorder epidemic as well as the increasing legalization and availability of marijuana, the authors sought to determine whether marijuana use reduced the non-medical use of prescribed opioids. In this 3-year follow-up study, the authors found that marijuana use actually increased the risk of opioid use and opioid use disorder in a dose-dependent manner. Several potential mechanisms through which this association may be mediated are hypothesized (Figure). Although further research is needed, the authors suggest caution, given that many regions of the United States have recently passed legislation regarding both recreational and medical marijuana use.
|Figure. Hypothesized Mechanisms By Which Increased Marijuana Use May Lead to Increased Opioid Use.
Increasing marijuana use may lead to a sensitization of effects on dopaminergic neurotransmission; behavioral disinhibition leading to increased risk of using other substances; increased access and social exposure to substances of abuse; or excessive need for relief from pain not effectively ameliorated by either marijuana or opioid use alone.
Olfson M, Wall MM, Liu S-M et al. Cannabis use and risk of prescription opioid use disorder in the United States. Am J Psychiatry 2018;175(1):47-53.
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