Evocative gene-environment correlation between genetic risk for schizophrenia and bullying victimization

Bullying exposure concerns over 10% of adolescents in Europe. Moreover, bullying victimization is heritable and victims are liable to psychotic symptoms, partly because of shared heritability with psychosis. The genetic component of bullying victimization has been proposed to involve the social reactions elicited by victims – a mechanism called “evocative gene-environment correlation”. We hypothesized that genetic risk for schizophrenia, a heritable disease also associated with social stress during childhood and adolescence, is related with social experiences during adolescence and is involved in the risk of developing psychotic symptoms. We studied 908 individuals of the TRAILS sample and found that 13-14-year-old adolescents with greater genetic risk for schizophrenia are more exposed to bullying assessed via peer nomination scores than their peers with lower genetic risk. Importantly, bullying victimization mediated the path from genetic risk to the frequency of psychotic symptoms about three years later. These findings provide evidence of a previously unreported form of gene-environment interplay that may be a mechanism of risk for psychosis and schizophrenia. To the extent that genetic risk translation into clinical symptoms is mediated by environmental risk factors, this evidence supports mental health prevention aimed at antagonizing bullying victimization in vulnerable individuals.