Independent contribution of polygenic risk for schizophrenia and cannabis use in predicting psychotic-like experiences in young adulthood: testing gene × environment moderation and mediation.
Psychological medicine April 1, 2023 Laurent Elkrief, Bochao Lin, Mattia Marchi et al.
Cannabis use at age 16 is associated with psychotic-like experiences (PLEs) even after accounting for genetic risk for schizophrenia, according to an analysis of 1740 European adolescents from the IMAGEN cohort and replicated in 1223 individuals from a Dutch cohort. Polygenic risk scores for schizophrenia predicted both cannabis use and PLEs, and cannabis use remained a significant predictor of PLEs in models including genetic risk. However, no evidence was found that genetic risk mediates or moderates the cannabis–psychosis link. The findings suggest cannabis use is a risk factor for PLEs independent of genetic vulnerability to schizophrenia.