The Impact of Cannabis Use on Cognitive Functioning in Patients With Schizophrenia: A Meta-analysis of Existing Findings and New Data in a First-Episode Sample.

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Version: author
Serval ID
serval:BIB_848D7CB4EF27
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
The Impact of Cannabis Use on Cognitive Functioning in Patients With Schizophrenia: A Meta-analysis of Existing Findings and New Data in a First-Episode Sample.
Journal
Schizophrenia Bulletin
Author(s)
Yücel M., Bora E., Lubman D.I., Solowij N., Brewer W.J., Cotton S.M., Conus P., Takagi M.J., Fornito A., Wood S.J., McGorry P.D., Pantelis C.
ISSN
1745-1701 (Electronic)
ISSN-L
0586-7614
Publication state
Published
Issued date
2012
Peer-reviewed
Oui
Volume
38
Number
2
Pages
316-330
Language
english
Notes
Publication types: Journal ArticlePublication Status: ppublish
Abstract
Cannabis use is highly prevalent among people with schizophrenia, and coupled with impaired cognition, is thought to heighten the risk of illness onset. However, while heavy cannabis use has been associated with cognitive deficits in long-term users, studies among patients with schizophrenia have been contradictory. This article consists of 2 studies. In Study I, a meta-analysis of 10 studies comprising 572 patients with established schizophrenia (with and without comorbid cannabis use) was conducted. Patients with a history of cannabis use were found to have superior neuropsychological functioning. This finding was largely driven by studies that included patients with a lifetime history of cannabis use rather than current or recent use. In Study II, we examined the neuropsychological performance of 85 patients with first-episode psychosis (FEP) and 43 healthy nonusing controls. Relative to controls, FEP patients with a history of cannabis use (FEP + CANN; n = 59) displayed only selective neuropsychological impairments while those without a history (FEP - CANN; n = 26) displayed generalized deficits. When directly compared, FEP + CANN patients performed better on tests of visual memory, working memory, and executive functioning. Patients with early onset cannabis use had less neuropsychological impairment than patients with later onset use. Together, these findings suggest that patients with schizophrenia or FEP with a history of cannabis use have superior neuropsychological functioning compared with nonusing patients. This association between better cognitive performance and cannabis use in schizophrenia may be driven by a subgroup of "neurocognitively less impaired" patients, who only developed psychosis after a relatively early initiation into cannabis use.
Pubmed
Web of science
Open Access
Yes
Create date
05/03/2012 14:07
Last modification date
20/08/2019 14:44
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