Cannabis Tolerance: A Scope Review

Cannabis is a widely consumed drug, so studying the effects of its chronic consumption becomes relevant. Regarding chronic consumption, the phenomenon of tolerance has been described in several drugs, including cannabis. Currently, multiple studies have addressed this phenomenon, with high heterogeneity in terms of methodology, evidence, and results. We aim to describe and analyze the literature on cannabis tolerance evaluated in physiological, cognitive, behavioral, and subjective responses, incorporating a critical perspective to account for some gaps and controversies in its study. Cannabis tolerance shows a disparity between the effects produced after a first administration compared to its chronic use. Each of them incorporates heterogeneity of cannabinoids, doses, and routes of administration. Also, there is diversity in the regularity and temporal extension of consumption and its effects at the different response levels. Even when the heterogeneity of measurements allows for incorporating different perspectives, this results in poor standardization and a lack of rigor in what is understood as cannabis tolerance. Furthermore, there is no consideration of the stimuli present at drug administration, which have been relevant in the understanding of tolerance to other drugs as a learning process. Cannabis tolerance should be further studied, incorporating rigorous definitions and measurements that allow the phenomenon to be addressed in a global and standardized manner.