ReviewAcute and Chronic Effects of Cannabinoids on Human Cognition—A Systematic Review
Section snippets
Method
This systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (Figure 1) (33). The search strategy and data extraction are detailed in Supplement 1, and selection criteria, resulting in 105 studies included for review, are provided in the legend of Figure 1. From each study, we extracted participant demographics (age, sex, IQ), cannabis use metrics (e.g., age of onset and duration, frequency, and quantity of use), period of
Results
We provide a summary appraisal of findings organized by primary cognitive domain in order of evidential strength from most to least consistently impaired. A more detailed account of findings from all studies is provided in Supplement 1, and detailed data extracted from each article are tabulated in Table S1 in Supplement 2. Within each cognitive domain, we address first acute administration studies, then studies of chronic exposure to cannabis, followed briefly by abstinence studies. Further
Discussion
In general, the literature on the cognitive effects of cannabis exposure continues to be plagued with complexity in terms of heterogeneity of both the extent of cannabis exposure in the samples assessed and the means of assessing cognitive function (18, 19, 20, 21). The nature of the samples recruited and the way in which prior exposure to cannabis is quantified affect interpretation of findings for acute and chronic effects. In studies of chronic users, associations with frequency of use are
Conclusions
Further significant evidence has emerged supporting the finding that acute and chronic exposure to cannabinoids impairs cognition, especially in the domains of verbal learning, memory, and attention (Table 2). Mixed evidence across the range of other cognitive domains is likely due to ongoing heterogeneity in the cognitive tests employed, prior cannabis use histories, and the assessment of cannabis use metrics as well as the neurodevelopmental stage at both onset and cessation of cannabis use.
Acknowledgments and Disclosures
This work was supported by the Australian Research Council Future Fellowship Grant No. FT110100752 (to NS) and National Health and Medical Research Council Project Grant No. 1007593 (to NS) and Senior Research Fellowship Grant No. 1021973 (to MY).
We thank Madeleine Godber for assistance with literature searches and document retrieval.
The authors report no biomedical financial interests or potential conflicts of interest.
References (150)
- et al.
The brain effects of cannabis in healthy adolescents and in adolescents with schizophrenia: A systematic review
Psychiatry Res
(2013) - et al.
Cannabis use and risk of psychotic or affective mental health outcomes: A systematic review
Lancet
(2007) - et al.
Proportion of patients in south London with first-episode psychosis attributable to use of high potency cannabis: A case-control study
Lancet Psychiatry
(2015) - et al.
Cannabis use and mania symptoms: A systematic review and meta-analysis
J Affect Disord
(2015) - et al.
Young adult sequelae of adolescent cannabis use: An integrative analysis
Lancet Psychiatry1
(2014) - et al.
Cannabis and adolescent brain development
Pharmacol Ther
(2015) - et al.
The role of cannabinoids on neuroanatomical alterations in cannabis users
Biol Psychiatry
(2016) - et al.
Schizophrenia, ketamine and cannabis: Evidence of overlapping memory deficits
Trends Cogn Sci
(2006) - et al.
Gender moderates the impact of stereotype threat on cognitive function in cannabis users
Addict Behav
(2010) - et al.
Longitudinal study of cognition among adolescent marijuana users over three weeks of abstinence
Addict Behav
(2010)
Cannabis use and neurocognitive functioning in a non-clinical sample of users
Addict Behav
Interactions between specific parameters of cannabis use and verbal memory
Prog Neuropsychopharmacol Biol Psychiatry
Cognitive performance in a placebo-controlled pharmacotherapy trial for youth with marijuana dependence
Addict Behav
An exploratory study of the combined effects of orally administered methylphenidate and delta-9-tetrahydrocannabinol (THC) on cardiovascular function, subjective effects, and performance in healthy adults
J Subst Abuse Treat
Separate and combined effects of the cannabinoid agonists nabilone and delta(9)-THC in humans discriminating delta(9)-THC
Drug Alcohol Depend
Separate and combined effects of the GABA-A positive allosteric modulator diazepam and delta(9)-THC in humans discriminating delta(9)-THC
Drug Alcohol Depend
The dose effects of short-term dronabinol (oral THC) maintenance in daily cannabis users
Drug Alcohol Depend
Long-term heavy marijuana users make costly decisions on a gambling task
Drug Alcohol Depend
Neurocognitive consequences of marihuana—a comparison with pre-drug performance
Neurotoxicol Teratol
Neuropsychological deficits associated with cannabis use in young adults
Drug Alcohol Depend
Cannabis dependence, cognitive control and attentional bias for cannabis words
Addict Behav
Selective processing of cannabis cues in regular cannabis users
Drug Alcohol Depend
National Drug Strategy Household Survey
World Drug Report 2014
Adverse health effects of marijuana use
N Engl J Med
The adverse health effects of chronic cannabis use
Drug Test Anal
Structural and functional imaging studies in chronic cannabis users: A systematic review of adolescent and adult findings
PLoS One
Structural MRI findings in long-term cannabis users: What do we know?
Subst Use Misuse
The association between regular cannabis exposure and alterations of human brain morphology: An updated review of the literature
Curr Pharm Des
Acute and non-acute effects of cannabis on human memory function: A critical review of neuroimaging studies
Curr Pharm Des
Imaging the neural effects of cannabinoids: Current status and future opportunities for psychopharmacology
Curr Pharm Des
Neuroimaging in cannabis use: A systematic review of the literature
Psychol Med
Gone to pot—a review of the association between cannabis and psychosis
Front Psychiatry
Cannabis use during adolescent development: Susceptibility to psychiatric illness
Front Psychiatry
The chronic effects of cannabis on memory in humans: A review
Curr Drug Abuse Rev
Cannabis and cognitive dysfunction: Parallels with endophenotypes of schizophrenia?
J Psychiatry Neurosci
Cognitive abnormalities and cannabis use
Rev Bras Psiquiatria
Cannabis and cognition: Short and long-term effects
An evidence based review of acute and long-term effects of cannabis use on executive cognitive functions
J Addict Med
[18F]MK-9470, a positron emission tomography (PET) tracer for in vivo human PET brain imaging of the cannabinoid-1 receptor
Proc Natl Acad Sci U S A
Cannabis use in adolescence and risk for adult psychosis: Longitudinal prospective study
BMJ
Cannabis dependence and psychotic symptoms in young people
Psychol Med
Cannabis use and psychosis: A longitudinal population-based study
Am J Epidemiol
Self reported cannabis use as a risk factor for schizophrenia in Swedish conscripts of 1969: Historical cohort study
BMJ
Cannabis-associated psychosis: Current status of research
CNS Drugs
Opposite effects of delta-9-tetrahydrocannabinol and cannabidiol on human brain function and psychopathology
Neuropsychopharmacology
Neuroimaging studies of acute effects of THC and CBD in humans and animals: A systematic review
Curr Pharm Des
Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement
PLoS Med
The acute effects of cannabinoids on memory in humans: A review
Psychopharmacology
The psychotomimetic effects of intravenous delta-9-tetrahydrocannabinol in healthy individuals: Implications for psychosis
Neuropsychopharmacology
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SJB, HHvH, and NS contributed equally to this work.