AUD runs in families with an estimated heritability of 40%–60% (Heath and Martin, 1994, Prescott and Kendler, 1999, Verhulst et al., 2015). First-degree family history of AUD, which encompasses both genetic and shared family environmental factors (Dawson et al., 1992, Grant, 1998, Dawson, 2000, Dawson and Grant, 1998), has been demonstrated as an AUD risk factor with odds ratios (OR) 1.91–2.38 (Dawson et al., 1992, Karriker-Jaffe et al., 2021). In the U.S., about 19% of adults reported at least one first-degree relative having some alcohol use problems (Karriker-Jaffe et al., 2021). However, not everyone knows or accurately reports their family history (Schuckit et al., 2020); for example, there may be a parent who has a prior history of AUD but is no longer engaging in problem drinking during the observation period. Another issue is that family members carrying high risk may abstain from drinking for religious, health, or other reasons. For complex disorders (i.e., disorders caused by many genes with small effects along with environmental factors) such as AUD, many patients are not expected to have a positive family history,
