Further Evidence That Cannabis Moderates Familial Correlation of Psychosis-Related Experiences

Ruud van Winkel*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Background Familial correlations underlie heritability estimates of psychosis. If gene-environment interactions are important, familial correlation will vary as a function of environmental exposure. Methods Associations between sibling and parental schizotypy (n = 669 pairs, n = 1222 observations), and between sibling schizotypy and patient CAPE psychosis (n = 978 pairs, n = 1723 observations) were examined as a function of sibling cannabis use. This design is based on the prediction that in unaffected siblings who are not exposed, vulnerability for psychosis will remain latent, whereas in case of exposure, latent psychosis vulnerability may become expressed, at the level of schizotypal symptoms, causing the phenotypic correlation between relatives to become "visible" under the influence of cannabis. Results Siblings exposed to recent cannabis use resembled their patient-relative more closely in terms of positive schizotypy (urinalysis(+): B = 0.30, P
Original languageEnglish
Article numbere0137625
Number of pages12
JournalPLOS ONE
Volume10
Issue number9
DOIs
Publication statusPublished - 18 Sept 2015

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