As expected, increasing criterion count (ie, single criterion, mild, moderate, and severe AUD) was associated with increasing levels of heavy alcohol use and greater psychiatric comorbidity (Table 1). For instance, 48.9% and 82.4% of individuals with mild-to-moderate and severe AUD, respectively, reported experiencing blackouts. Likewise, 80% of those with severe AUD met criteria for a comorbid SUD vs half of those with mild-to-moderate AUD. Count-based severity was also reflected in reduced P300 amplitude and theta and delta EROs in individuals with severe vs mild-to-moderate AUD. AUD PGS also differentiated between severe and no AUD in the European ancestry subsample (odds ratio [OR], 1.23; 95% CI, 1.12-1.35) and between severe and mild AUD in the African American ancestry subsample (OR, 1.27; 95% CI, 1.07-1.51) (eTable 3 in Supplement 1). Individuals with mild AUD differed from those with moderate AUD on alcohol-related and psychiatric variables, but overall differences between these 2 severity groups were less pronounced than those between moderate and severe AUD or between mild-to-moderate and severe AUD. The extent of observed differences between mild and moderate AUD, as opposed to
