Association between stressful life events and psychotic experiences in adolescence: evidence for gene-environment correlations.

Abstract

BackgroundStressful life events (SLEs) are associated with psychotic experiences. SLEs might act as an environmental risk factor, but may also share a genetic propensity with psychotic experiences.AimsTo estimate the extent to which genetic and environmental factors influence the relationship between SLEs and psychotic experiences.MethodSelf- and parent reports from a community-based twin sample (4830 16-year-old pairs) were analysed using structural equation model fitting.ResultsSLEs correlated with positive psychotic experiences (r = 0.12–0.14, all P<0.001). Modest heritability was shown for psychotic experiences (25–57%) and dependent SLEs (32%). Genetic influences explained the majority of the modest covariation between dependent SLEs and paranoia and cognitive disorganisation (bivariate heritabilities 74–86%). The relationship between SLEs and hallucinations and grandiosity was explained by both genetic and common environmental effects.ConclusionsFurther to dependent SLEs being an environmental risk factor, individuals may have an underlying genetic propensity increasing their risk of dependent SLEs and positive psychotic experiences.