SIB# 375 - Cannabis and Cognitive Function

The Study: Evidence on the acute and residual neurocognitive effects of cannabis use in adolescents and adults: a systematic meta review of meta-analyses

Overview: This study is a meta review of previous meta-analyses of the effects of cannabis on performance of various cognitive tests.

Key Points: 

·         Cannabis is among the most consumed psychoactive substances  and is currently the subject of numerous changes in public policy. 

·         This review looks at the effects of cannabis on cognition in both adolescents and adults 

·         This “meta-review included 10 prior meta-analyses” which covered cognitive functions such as executive function, learning and memory, processing speed, perceptual motor function and language. 

·         The most robust evidence of impairment was in the areas of verbal learning and memory and these impairments persisted after intoxication had passed. 

·         Small-Moderate impairments were also seen in executive function, working memory, processing speed, attention and decision making. 

·         In young subjects, heavy cannabis use was associated with residual neuro cognitive deficits.  

Author’s Conclusions: “cannabis intoxication leads to small to moderate deficits in several cognitive domains. These acute impairments accord with documented residual effects, suggesting that the detrimental effects of cannabis persist beyond acute intake.” 

Reviewer's Comments: Cannabis, despite the hue and cry of those who expound its virtues as a harmless recreational drug, not only impairs the cognitive function of its users but does so on a number of different levels. I have no illusions that this article will in any way dissuade those who are fans of this drug, but perhaps those policy makers who can still focus on the data will give serious thought before granting further societal approval to yet another harmful intoxicant.

 Reviewer:  Mark R. Payne DC

 Reference: Dellazizzo L, Potvin, Giguere S, Dumais A.  Evidence on the acute and residual neurocognitive effects of cannabis use in adolescents and adults: a systematic meta review of meta-analyses. Addiction SSA. 2021 

Link To Full Text: https://onlinelibrary.wiley.com/d