Future directions include replication of these results in general population samples and with other complex phenotypes. Additionally, future work may investigate the application of this correction to polygenic gene-by-environment interaction (GxE) analyses. Spurious GxE effects may be detected if the effect of the heritable environment on the target phenotype is moderated by unmeasured confounding variables (Akimova et al., 2021; Keller, 2014). Phenotypic PC covariates could be applied to correct these spurious results by the approach recommended in Keller et al. (2014), computing interactions between each phenotypic PC and the heritable environment of interest. Adequate correction of collider bias in polygenic association analyses may improve estimates of the influence of genetic risk on complex phenotypes in the presence of heritable covariates across a wide range of research designs.
