Among the heterogeneous and polygenic characteristics involved in the alcoholism risk are variations in alcohol metabolism, the presence of problematic externalizing behaviors (e.g., impulsivity), as well as the manner in which a person responds to alcohol (Li, 2000; Sher et al., 2005; Slutske et al., 2002). The latter includes differences in how alcohol affects reactions to stress and how rapidly rising blood alcohol levels (BACs) can produce an exaggerated overall response in some drinkers (Finn et al., 1990; Morzorati et al., 2002). Perhaps the most intensively studied alcohol reaction characteristic related to future AUDs, however, is the low level of response (LR) to alcohol observed at peak and falling blood levels after oral administration (Schuckit, 2009). LR refers to the intensity of response to alcohol at a specified BAC or to the retrospective recall of the number of standard drinks usually needed for a range of effects.
