Psychotic experiences are linked to cannabis use in adolescents in the community because of common underlying environmental risk factors
Shakoor, Sania and Zavos, H. and McGuire, P. and Cardno, A.G. and Freeman, D. and Ronald, Angelica (2015) Psychotic experiences are linked to cannabis use in adolescents in the community because of common underlying environmental risk factors. Psychiatry Research 227 (2-3), pp. 144-151. ISSN 0165-1781.
11923.pdf - Accepted Version
Download (922kB) | Preview
11923a.pdf - Published Version
Available under License Creative Commons Attribution.
Download (291kB) | Preview
Cannabis users are more likely to have psychotic experiences (PEs). The degree to which these associations are driven by genetic or environmental influences in adolescence is unknown. This study estimated the genetic and environmental contributions to the relationship between cannabis use and PEs. Specific PEs were measured in a community-based twin sample (4,830 16-year-old pairs) using self-reports and parent-reports. Adolescents reported on ever using cannabis. Multivariate liability threshold structural equation model-fitting was conducted. Cannabis use was significantly correlated with PEs. Modest heritability (37%), common environmental influences (55%) and unique environment (8%) were found for cannabis use. For PEs, modest heritability (27–54%), unique environmental influences (E=12–50%) and little common environmental influences (11–20%), with the exception of parent-rated Negative Symptoms (42%), were reported. Environmental influences explained all of the covariation between cannabis use and paranoia, cognitive disorganization and parent-rated negative symptoms (bivariate common environment=69–100%, bivariate unique environment=28–31%), whilst the relationship between cannabis use and hallucinations indicated familial influences. Cannabis use explains 2–5% of variance in positive, cognitive, and negative PEs. Cannabis use and psychotic experience co-occur due to environmental factors. Focus on specific environments may reveal why adolescent cannabis use and psychotic experiences tend to ‘travel together’.
|Additional Information:||NOTICE: this is the author’s version of a work that was accepted for publication in Psychiatry Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Psychiatry Research Online First, 14th April 2015|
|Keyword(s) / Subject(s):||Psychotic experiences, Cannabis use, Genetics, Twin study, Adolescence|
|School:||Birkbeck Schools and Departments > School of Science > Psychological Sciences|
|Research Centre:||Brain and Cognitive Development, Centre for (CBCD)|
|Depositing User:||Angelica Ronald|
|Date Deposited:||17 Apr 2015 11:19|
|Last Modified:||02 Dec 2016 11:55|
Additional statistics are available via IRStats2.