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Cited by 563

The DOI matches its Crossref record; 6 of the 6 references it cites were found in a registry or an index.

Cannabis Use and Earlier Onset of Psychosis: A Systematic Meta-analysis

Large, Matthew, Sharma, Swapnil, Compton, Michael T., Slade, Tim, Nielssen, Olav·2011·Archives of General Psychiatry
DOI 10.1001/archgenpsychiatry.2011.5
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Abstract

CONTEXT: A number of studies have found that the use of cannabis and other psychoactive substances is associated with an earlier onset of psychotic illness. OBJECTIVE: To establish the extent to which use of cannabis, alcohol, and other psychoactive substances affects the age at onset of psychosis by meta-analysis. DATA SOURCES: Peer-reviewed publications in English reporting age at onset of psychotic illness in substance-using and non-substance-using groups were located using searches of CINAHL, EMBASE, MEDLINE, PsycINFO, and ISI Web of Science. STUDY SELECTION: Studies in English comparing the age at onset of psychosis in cohorts of patients who use substances with age at onset of psychosis in non-substance-using patients. The searches yielded 443 articles, from which 83 studies met the inclusion criteria. DATA EXTRACTION: Information on study design, study population, and effect size were extracted independently by 2 of us. DATA SYNTHESIS: Meta-analysis found that the age at onset of psychosis for cannabis users was 2.70 years younger (standardized mean difference = -0.414) than for nonusers; for those with broadly defined substance use, the age at onset of psychosis was 2.00 years younger (standardized mean difference = -0.315) than for nonusers. Alcohol use was not associated with a significantly earlier age at onset of psychosis. Differences in the proportion of cannabis users in the substance-using group made a significant contribution to the heterogeneity in the effect sizes between studies, confirming an association between cannabis use and earlier mean age at onset of psychotic illness. CONCLUSIONS: The results of meta-analysis provide evidence for a relationship between cannabis use and earlier onset of psychotic illness, and they support the hypothesis that cannabis use plays a causal role in the development of psychosis in some patients. The results suggest the need for renewed warnings about the potentially harmful effects of cannabis.

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Metadata

Authors
Large, M., Sharma, S., Compton, M. T., Slade, T., & Nielssen, O.
Venue
Archives of General Psychiatry
Publisher
American Medical Association (AMA)
Published
2011-06-06
Volume
68
Issue
6
Pages
555
ISSN
0003-990X (ISSN-L)
DOI
10.1001/archgenpsychiatry.2011.5
OpenAlex
W2016732910
Cited by
563
References
6
FWCI
32.96
Type
journal article
Language
en
Open access
closed

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