Anne K Schlag, Chandni Hindocha, Rayyan Zafar, David J Nutt, H Valerie Curran
February 17, 2021
This Drug Science research was published in the Journal of Psychopharmacology.
For recreational users, the estimated chances of becoming dependent on cannabis after any lifetime exposure is 8.9%, which is considerably lower than for cocaine (20.9%), alcohol (22.7%) or tobacco (67.5%). Nonetheless, the United Nations reports that cannabis dependence is now the primary reason for drug treatment across the world (39%), surpassing numbers receiving opioid treatment (33%).
But does this remain true for medical cannabis users?
Research on medical cannabis dependence is still in its infancy. Most of the studies on cannabis dependence have been conducted in relation to recreational use, which substantially differs from the medical application of cannabis. The differences between medical and recreational cannabis use and users highlight the challenges of simply extrapolating findings from the recreational cannabis literature. Many questions about the potential for medical cannabis use to lead to dependence remain to be answered. It is imperative to address these questions in order to be able to minimise harms of medical cannabis use. Here, we offer a narrative review of the literature and consider to what extent research on recreational cannabis dependence might be applied to medical cannabis dependence.
Cannabis has been legalised for medical use in an ever-increasing number of countries. A growing body of scientific evidence supports the use of medical cannabis for a range of therapeutic indications. In parallel with these developments, concerns have been expressed by many prescribers that increased use will lead to patients developing cannabis use disorder. Cannabis use disorder has been widely studied in recreational users, and these findings have often been projected onto patients using medical cannabis. However, studies exploring medical cannabis dependence are scarce and the appropriate methodology to measure this construct is uncertain.
This article provides a narrative review of the current research to discern if, how and to what extent, concerns about problems of dependence in recreational cannabis users apply to prescribed medical users. We focus on the main issues related to medical cannabis and dependence, including the importance of dose, potency, cannabinoid content, pharmacokinetics and route of administration, frequency of use, as well as set and setting.