Reduced amplitude of the P3b event-related potential (ERP) is a robust finding in individuals with alcohol use disorders (AUDs), as well as in those with a family history of AUDs (Begleiter and Porjesz, 1999; Begleiter et al., 1984; Fein and Chang, 2006; Iacono et al., 2003). Some literature argues that the P3b reduction is a physiological correlate of chronic alcohol exposure. For instance, animal studies suggest that relatively brief alcohol exposure in adolescence is sufficient to result in P300 changes that endure into adulthood (see, e.g., Criado et al., 2008; Ehlers and Criado, 2010). However, most studies propose that the P3b reduction is an endophenotypic marker for the genetic vulnerability to AUDs (Bauer, 2001; Begleiter and Porjesz, 1988; Hill et al., 1999B, 2009; Pfefferbaum et al., 1991). Furthermore, chronic alcohol use and genetic vulnerability to AUDs may contribute independently to the P3b reduction (Perlman et al., 2009). Because chronic alcohol exposure and genetic risk for AUDs commonly co-occur, it is often difficult to determine the relative contribution of each to the P3b reduction.
