A low level of response (LR) to alcohol is one of the more extensively studied of the preexisting phenotypes that predispose a person toward alcohol problems (Ehlers et al., 2010; Morean and Corbin, 2010; Newlin and Renton, 2010; Quinn and Fromme, 2011; Ray et al., 2011). Early evaluations of LR used challenges with alcohol where changes from baseline to a given blood alcohol concentration (BAC) were documented through alterations in hormones, electrophysiology, motor performance, and subjective feelings of intoxication (Schuckit, 2009; Schuckit and Gold, 1988). Lower responses to alcohol were seen in groups at high risk for future alcohol use disorders (AUDs), including those with a family history of AUDs, Native Americans and Koreans, while high LRs have been observed in groups with lower vulnerabilities toward alcohol problems, including Jewish subjects and Asian individuals with the alcohol-related flush (Duranceaux et al., 2006, 2008; Ehlers et al., 2004; Garcia-Andrade et al., 1997; Luczak et al., 2011; Monteiro et al., 1991). All longitudinal studies to date have reported that low LR’s documented through alcohol challenges predicted later heavy drinking and alcohol problems (e.g., Heath et al., 1999; Schuckit and Smith, 1996; Volavka et al., 1996).
