Effects of Cannabis Use on Neurocognition: A Scoping Review of MRI Studies

Cannabis is one of the most commonly utilized recreational drugs. However, increasing evidence from the literature suggests harmful implications on cognition. Thus, the main aim of the current review is to summarize literature findings pertaining to the impact of cannabis on neurocognitive skills, focusing on the imaging biomarkers provided by MRI. Two reviewers navigated the literature independently using four main search engines including PubMed and Cochrane. Articles were first evaluated through their title and abstract, followed by full-text assessment. Study characteristics and findings were extracted, and the studies' quality was appraised. 47 articles were included. The majority of the studies were of a case-control design (66%), and the most studied neurocognitive skill was memory (40.4%). With task-based fMRI being the most commonly utilized MRI technique, findings have shown significantly varying decreased and increased neuronal activity within brain regions associated with the cognitive tasks performed. Results suggest that cannabis users are significantly suffering from cognitive deficits. The major significance of this review is attributed to highlighting the role of MRI. Future research needs to delve more into validating the negative effects of cannabis, to enable stakeholders to take action to limit cannabis usage, to foster public health and wellbeing.