Recommendation to reconsider examining cannabis subtypes together due to opposing effects on brain, cognition and behavior

A commentary argues that most research on cannabis has treated it as a single substance, obscuring the opposing cognitive effects of THC and CBD. The authors contend that rising cannabis potency over the past two decades limits the generalizability of older studies to current public health. They urge future research to separately examine THC and CBD and to measure potency to better understand cannabis's impact on cognition and health.

Study at a glance

Abstract

Cannabis use represents a major public health issue throughout the globe. Yet, we still lack the most fundamental knowledge on long-term effects of cannabis on neural, cognitive, and behavioral function. Part of this stems from how cannabis has been measured historically. To this end, most empirical examinations of cannabis have consolidated all types of cannabis collectively. However, this approach obscures differences in how cannabinoids operate. In this commentary, we address the contrasting properties of tetrahydrocannabinol (THC) and cannabidiol (CBD) and their opposing effects on cognitive function. In addition, we address the increase in cannabis potency throughout the past two decades and how that impacts generalizability of early data to evaluations of contemporary public health. We underscore the urgent need for future research to disaggregate examination of THC from CBD, along with the importance of measuring cannabis potency to more effectively unravel its influence on cognitive function and other health issues.