Duperrouzel JC, et al. - Given the variances in results of studies examining the impact of cannabis use on neurocognitive functioning, researchers conducted a systematic literature search for peer-reviewed meta-analyses of neurocognitive or functional neuroimaging data focusing on this topic. They used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to conduct this search. As per current findings, regular healthy cannabis users vs nonusers show poorer neurocognitive functioning of small to medium effect sizes across many neurocognitive domains and have functional brain alterations, regardless of age. They noted no uniform adverse effects across neurocognitive domains. These studies equivocally yielded evidence for poorer neurocognitive outcomes among adolescent-onset users. More research (particularly large-scale longitudinal studies) is still required to determine critical periods or patterns of use that may more frequently lead to negative outcomes.