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Cited by 567Cannabis and Cannabinoid ResearchSchizophrenia research and treatmentForensic Toxicology and Drug Analysis

The DOI matches its Crossref record; 15 of the 15 references it cites were found in a registry or an index.

High-potency cannabis and the risk of psychosis

Open access
Di Forti, Marta, Morgan, Craig, Dazzan, Paola, Pariante, Carmine, Mondelli, Valeria, Marques, Tiago Reis, Handley, Rowena, Luzi, Sonija, Russo, Manuela, Paparelli, Alessandra, Butt, Alexander, Stilo, Simona A., Wiffen, Ben, Powell, John, Murray, Robin M.·2009·British Journal of Psychiatry
DOI 10.1192/bjp.bp.109.064220PMC PMC2801827
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Abstract

Background: People who use cannabis have an increased risk of psychosis an effect attributed to the active ingredient δ9-tetrahydrocannabinol (Δ9-THC). There has recently been concern over an increase in the concentration of Δ9-THC in the cannabis available in many countries. Aims: To investigate whether people with a first episode of psychosis were particularly likely to use high-potency cannabis. Method: We collected information on cannabis use from 280 cases presenting with a first episode of psychosis to the South London & Maudsley National Health Service (NHS) Foundation Trust, and from 174 healthy controls recruited from the local population. Results: There was no significant difference between cases and controls in whether they had ever taken cannabis, or age at first use. However, those in the cases group were more likely to be current daily users (OR = 6.4) and to have smoked cannabis for more than 5 years (OR = 2.1). Among those who used cannabis, 78% of the cases group used high-potency cannabis (sinsemilla, ‘skunk’) compared with 37% of the control group (OR 6.8). Conclusions: The finding that people with a first episode of psychosis had smoked higher-potency cannabis, for longer and with greater frequency, than a healthy control group is consistent with the hypothesis that Δ9-THC is the active ingredient increasing risk of psychosis. This has important public health implications, given the increased availability and use of high-potency cannabis.

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Research works printed but not linked: 5

  1. 2005, The Classification of Cannabis under the Misuse of Drugs Act 1971
  2. 1992, Schedules for Clinical Assessment in Neuropsychiatry (SCAN)
  3. 1992, The ICD–10 Classification of Mental and Behavioural Disorders. Clinical Description and Diagnostic Guidelines
  4. British Crime Survey, 2006–2007
  5. Hardwick, 2008, Home Office Cannabis Potency Study

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Metadata

Authors
Di Forti, M., Morgan, C., Dazzan, P., Pariante, C., Mondelli, V., Marques, T. R., Handley, R., Luzi, S., Russo, M., Paparelli, A., Butt, A., Stilo, S. A., Wiffen, B., Powell, J., & Murray, R. M.
Affiliations
Springfield University Hospital (GB)
ORCID
Venue
British Journal of Psychiatry
Publisher
Royal College of Psychiatrists
Published
2009-12
Volume
195
Issue
6
Pages
488-491
ISSN
  • 0007-1250 (ISSN-L)
  • 1472-1465
DOI
10.1192/bjp.bp.109.064220
PMC
PMC2801827
OpenAlex
W2104532446
Cited by
567
References
15
Citations by year
2026: 10 · 2025: 11 · 2024: 25 · 2023: 30 · 2022: 38 · 2021: 41 · 2020: 54 · 2019: 31 · 2018: 35 · 2017: 38 · 2016: 46 · 2015: 36 · 2014: 28 · 2013: 36 · 2012: 29
FWCI
25.87
Type
journal article
Language
en
Open access
Licence
www.cambridge.org/core/terms (unspecified, 2954 d)
Locations
  • The British Journal of Psychiatry (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • Research Portal (King's College London) (submittedVersion)
Funders
King's College London
Topics
  • Health Sciences › Medicine › Pharmacology (medical) › Cannabis and Cannabinoid Research
  • Health Sciences › Medicine › Psychiatry and Mental health › Schizophrenia research and treatment
  • Life Sciences › Pharmacology, Toxicology and Pharmaceutics › Toxicology › Forensic Toxicology and Drug Analysis
Keywords
high-potency cannabis, psychosis, first-episode psychosis, delta-9-tetrahydrocannabinol, cannabis use, daily cannabis use, public health implications
MeSH terms
Adolescent, Adult, Age Factors, Aged, Cannabis, Female, Humans, London, Male, Marijuana Smoking, Middle Aged, Psychoses, Substance-Induced, Risk Factors, Dronabinol, Case-Control Studies, Young Adult

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