The target phenotype of the applied analysis is DSM-5 alcohol use disorder clinical criterion counts (AUD Sx). Collider bias occurs if a covariate is an outcome of two different variables; for example, if the covariate is associated with (1) the PRS and (2) an unmeasured confounding variable. We examine tobacco use and educational attainment as heritable collider variables. We selected these two variables as heritable collider variables for three reasons. First, tobacco use and educational attainment are genetically correlated with AUD , suggesting that a PRS for AUD may be associated with tobacco use and educational attainment (Kranzler et al., 2019; Walters et al., 2018; Zhou et al., 2020). Second, preliminary results indicate differing strengths of correlation with polygenic liability for AUD, providing a useful range of circumstances for examining the method. Third, tobacco use (Cheng & Furnham, 2021; Green et al., 2018) and educational attainment (Esch et al., 2014; Krapohl et al., 2014) are endogenous to a wide variety of other predictor variables. Given the wide variety of variables that predict tobacco use and educational attainment (Cheng & Furnham,
