Maximum consumption is also related to amplitude of the P300 wave of the event-related brain potential, a neurophysiologic indicator of liability for externalizing disorders in general, such as antisocial behavior and substance use disorders (SUDs) (Iacono, Malone, & McGue, 2003). P300 amplitude in a visual discrimination task is reduced in male offspring of fathers in the most deviant decile of the distribution on maximum consumption, but who did not meet diagnostic criteria for alcohol dependence (Iacono, Carlson, Malone, & McGue, 2002). The magnitude of reduction was comparable to that observed in offspring of alcoholic fathers, suggesting that alcoholism and maximum consumption reflect much the same neurophysiologic vulnerability. In addition, the simplicity of the maximum consumption phenotype makes it especially attractive; because it consists in a single question, it can be assessed more easily than alcohol dependence. Understanding the degree to which it confers risk to offspring may have clinical utility in addition to scientific value.
