The DOI matches its Crossref record; 36 of the 36 references it cites were found in a registry or an index.
Sub-chronic impact of cannabinoids in street cannabis on cognition, psychotic-like symptoms and psychological well-being
Abstract
BACKGROUND: Cannabis varies considerably in levels of its two major constituent cannabinoids - (delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Recently, we found evidence that those who smoked cannabis containing detectable levels of CBD had fewer psychotic-like symptoms than those whose cannabis had no CBD. The present study aimed, first, to replicate those findings and, second, to determine whether protective effects of CBD may extend to other harms of cannabis, such as memory impairment and reduced psychological well-being. METHOD: A total of 120 current cannabis smokers, 66 daily users and 54 recreational users were classified into groups according to whether analysis of their hair revealed the presence or absence of CBD and high versus low levels of THC. All were assessed on measures of psychosis-like symptoms, memory (prose recall; source memory) and depression/anxiety. RESULTS: Lower psychosis-like symptoms were found in those whose hair had CBD compared with those without. However, this was seen only in recreational users, who had higher levels of THC in their hair. Higher THC levels in hair were associated with increased depression and anxiety. Prose recall and source memory were poorer in daily users with high THC levels in hair while recognition memory was better in individuals with CBD present in hair. CONCLUSIONS: CBD attenuates the psychotic-like effects of cannabis over time in recreational users. Higher THC negatively impacts on memory and psychological well-being. These findings raise concerns for the harms stemming from use of varieties such as 'skunk' (sensimillia), which lack any CBD but currently dominate the supply of cannabis in many countries.
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“A number of studies indicate that cannabis strains containing higher THC:CBD ratios may result in greater risk of psychotic outcomes, and that CBD might have anti-psychotic properties (27)(28)(29)47).”
From Association Between Cannabis and Psychosis: Epidemiologic Evidence (2016) · cites this paper as [28]
In the citing paper
“These findings are consistent with the observation that marijuana users of samples containing higher CBD concentrations in addition to Δ9-THC are less likely to experience psychotic symptoms than those who smoke samples without CBD (87).”
From Translational investigation of the therapeutic potential of Cannabidiol (CBD): Toward a new age (2018) · cites this paper as [87]
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Acute and Chronic Effects of Cannabinoids on Human Cognition—A Systematic Review
Broyd, S. J., van Hell, H. H., Beale, C., Yücel, M., & Solowij, N. (2016) · Biological Psychiatry · doi:10.1016/j.biopsych.2015.12.002 · Cited by 674
Cannabis, a complex plant: different compounds and different effects on individuals
Atakan, Z. (2012) · Therapeutic Advances in Psychopharmacology · doi:10.1177/2045125312457586 · Cited by 612
Campos, A. C., Moreira, F. A., Gomes, F. V., Del Bel, E. A., & Guimarães, F. S. (2012) · Philosophical Transactions of the Royal Society B: Biological Sciences · doi:10.1098/rstb.2011.0389 · Cited by 475
Association Between Cannabis and Psychosis: Epidemiologic Evidence
Gage, S. H., Hickman, M., & Zammit, S. (2016) · Biological Psychiatry · doi:10.1016/j.biopsych.2015.08.001 · Cited by 379
Keep off the grass? Cannabis, cognition and addiction
Curran, H. V., Freeman, T. P., Mokrysz, C., Lewis, D. A., Morgan, C. J. A., & Parsons, L. H. (2016) · Nature reviews. Neuroscience · doi:10.1038/nrn.2016.28 · Cited by 389
Metadata
- Authors
- Morgan, C. J. A., Gardener, C., Schafer, G., Swan, S., Demarchi, C., Freeman, T. P., Warrington, P., Rupasinghe, I., Ramoutar, A., Tan, N., Wingham, G., Lewis, S., & Curran, H. V.
- Affiliations
- University College London (GB)
- Corresponding author
- Morgan, C. J. A.
- Venue
- Psychological Medicine
- Publisher
- Cambridge University Press (CUP)
- Published
- 2011-07-29
- Volume
- 42
- Issue
- 2
- Pages
- 391-400
- ISSN
- 0033-2917 (ISSN-L)
- 1469-8978
- OpenAlex
- W2108405197
- Cited by
- 195
- References
- 36
- Citations by year
- 2026: 4 · 2025: 6 · 2024: 5 · 2023: 13 · 2022: 14 · 2021: 21 · 2020: 20 · 2019: 17 · 2018: 16 · 2017: 18 · 2016: 14 · 2015: 19 · 2014: 9 · 2013: 11 · 2012: 8
- FWCI
- 6.56
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Psychological Medicine (publishedVersion)
- PubMed (publishedVersion)
- Research Bank (Australian Catholic University) (submittedVersion)
- UCL Discovery (University College London) (submittedVersion)
- Research Portal (King's College London) (submittedVersion)
- Research Explorer (The University of Manchester) (submittedVersion)
- Funders
- Medical Research Council
- Topics
- Health Sciences › Medicine › Pharmacology (medical) › Cannabis and Cannabinoid Research
- Life Sciences › Pharmacology, Toxicology and Pharmaceutics › Toxicology › Forensic Toxicology and Drug Analysis
- Health Sciences › Medicine › Psychiatry and Mental health › Schizophrenia research and treatment
- Keywords
- cannabinoids, cannabidiol, delta-9-tetrahydrocannabinol, psychotic-like symptoms, memory impairment, source memory, prose recall, depression, anxiety, psychological well-being, hair analysis
- MeSH terms
- Adolescent, Adult, Anxiety, Cannabidiol, Cognition Disorders, Depression, Female, Hair, Humans, Male, Marijuana Smoking, Memory, Psychoses, Substance-Induced, Schizotypal Personality Disorder, Illicit Drugs, Dronabinol, Young Adult
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