Interpretation of findings is complicated by conflicting definitions of alcoholism and “at-risk” status across studies. Nevertheless, a recent meta-analysis3 of published P3 high-risk studies (Polich et al. 1994) concluded that P3 may have predictive value as an index of vulnerability to alcoholism. Low P3 amplitude in young children has been found to predict alcohol and other drug (AOD) abuse in adolescence (Berman et al. 1993; Hill et al. 1995a). Additional confirmation comes from analyses of data obtained by the nationwide Collaborative Study on the Genetics of Alcoholism (COGA). In densely affected alcoholic families (i.e., those in which at least three first-degree relatives are alcoholic), P3 amplitudes were significantly lower in age- and sex-matched offspring of alcoholic fathers than in offspring of alcoholics from randomly selected control families or families with sporadic cases of alcoholism (Porjesz et al. 1996).
