In summary, subjective responses to alcohol represent an important phenotype for alcohol use and misuse. Research evidence suggests that the way in which individuals’ experience the pharmacological effects of alcohol influences their subsequent use of alcohol (e.g., Lewis & June, 1990; Wise & Bozarth, 1987) and the risk of developing an alcohol use disorder (Schuckit & Smith, 1996). Moreover, subjective responses to alcohol are heritable (Heath & Martin, 1991; Viken et al., 2003) and informative regarding the neuropharmacological effects of alcohol and their biological and genetic bases. The differentiator model of response to alcohol (Newlin & Thompson, 1990) has been influential in distinguishing two related and biologically-mediated processes that emerge during a single alcohol administration session, namely acute tolerance and acute sensitization. In the next sections we will first introduce the concept of endophenotypes in psychiatric research and then discuss the conceptualization of subjective responses to alcohol as an endophenotype for alcoholism.
