The emphasis in studies of low LR is on predicting onsets of heavy drinking and multiple alcohol problems. Therefore, subjects typically do not yet have the outcomes being predicted, and have not already passed through ages of risk for developing repetitive alcohol problems (the latter is to avoid selecting older participants who despite drinking have not developed problems and are less likely to carry the high-risk phenotype being studied). AUD risk is usually defined by an alcohol dependent relative or an ethnic group membership with high or low AUD risk (e.g., Ehlers et al., 2010; Montiero et al., 1989).
