Acute and Chronic Effects of Cannabinoids on Human Cognition—A Systematic Review

Abstract

Cannabis use has been associated with impaired cognition during acute intoxication as well as in the unintoxicated state in long-term users. However, the evidence has been mixed and contested, and no systematic reviews of the literature on neuropsychological task-based measures of cognition have been conducted in an attempt to synthesize the findings. We systematically review the empirical research published in the past decade (from January 2004 to February 2015) on acute and chronic effects of cannabis and cannabinoids and on persistence or recovery after abstinence. We summarize the findings into the major categories of the cognitive domains investigated, considering sample characteristics and associations with various cannabis use parameters. Verbal learning and memory and attention are most consistently impaired by acute and chronic exposure to cannabis. Psychomotor function is most affected during acute intoxication, with some evidence for persistence in chronic users and after cessation of use. Impaired verbal memory, attention, and some executive functions may persist after prolonged abstinence, but persistence or recovery across all cognitive domains remains underresearched. Associations between poorer performance and a range of cannabis use parameters, including a younger age of onset, are frequently reported. Little further evidence has emerged for the development of tolerance to the acutely impairing effects of cannabis. Evidence for potential protection from harmful effects by cannabidiol continues to increase but is not definitive. In light of increasing trends toward legalization of cannabis, the knowledge gained from this body of research needs to be incorporated into strategies to minimize harm. Review Acute and Chronic Effects of Cannabinoids on Human Cognition-A Systematic ReviewSamantha J. Broyd, Hendrika H. van Hell, Camilla Beale, Murat Yücel, and Nadia Solowij ABSTRACT Cannabis use has been associated with impaired cognition during acute intoxication as well as in the unintoxicated state in long-term users. However, the evidence has been mixed and contested, and no systematic reviews of the literature on neuropsychological task-based measures of cognition have been conducted in an attempt to synthesize the findings. We systematically review the empirical research published in the past decade (from January 2004 to February 2015) on acute and chronic effects of cannabis and cannabinoids and on persistence or recovery after abstinence. We summarize the findings into the major categories of the cognitive domains investigated, considering sample characteristics and associations with various cannabis use parameters. Verbal learning and memory and attention are most consistently impaired by acute and chronic exposure to cannabis. Psychomotor function is most affected during acute intoxication, with some evidence for persistence in chronic users and after cessation of use. Impaired verbal memory, attention, and some executive functions may persist after prolonged abstinence, but persistenc...

Cannabis and Neuropsychiatry, 1: Benefits and Risks

“…Clinical and Practical Psychopharmacology driving simulation studies have consistently shown that cannabis dose-dependently impairs psychomotor skills 7,10 ; this lends support to the hypothesis that cannabis use is a specific risk factor for traffic accidents.…”

“…Impairments continue to be demonstrable in several cognitive domains even after discontinuation of cannabis use. 7,12 Such impairments may represent reverse causality; that is, persons who have poorer cognitive functioning may be more vulnerable to cannabis use and abuse. Such impairments may also represent residual cannabis effects, or the effects of cannabis withdrawal.…”

“…Cannabis use has long been suggested to adversely affect cognition. A systematic review 7 concluded that verbal learning and memory and attention are functions that are most consistently impaired by acute and chronic cannabis use. Psychomotor impairment occurs most obviously during acute intoxication but may be detected in chronic users, as well.…”

A Functional 3′UTR Polymorphism (rs2235749) of Prodynorphin Alters microRNA-365 Binding in Ventral Striatonigral Neurons to Influence Novelty Seeking and Positive Reward Traits

“…Nevertheless, residual effects may have masked the effect of genotype variation on learning task performance and novelty-seeking behavior in the cannabis-dependent group. A number of studies have shown acute and short-term effects of cannabis on various domains of cognition (reviewed in Broyd et al, (2015)), which further underscores the need for future research that could disentangle pre-existing, acute and residual cognitive deficit in cannabis-dependent populations.…”

Mariguana y sus efectos sobre el cerebro, la toma de decisiones y la inteligencia. Una revisión narrativa

“…El objetivo de esta revisión narrativa es revisar y discutir lo que ocasiona en el cerebro y sus consecuencias en la toma de decisiones y la inteligencia. Otras revisiones han mostrado que la atención, la memoria y la función psicomotora están afectadas en consumidores de mariguana (por ejemplo, ver Broyd, van Hell, Beale, Yücel, & Solowij, 2015), pero poco se ha revisado sobre los efectos del consumo y la toma de decisiones y la inteligencia.…”