In a separate study, Carlson et al. (2007) found that trajectories in P300 amplitude differentiated young men whose fathers had an antisocial behavior disorder (and thus were at high genetic risk) from those whose fathers were free of antisocial or substance use disorders. In addition to having smaller P300 amplitude responses at age 17, high-risk subjects showed slower rate of change than low-risk ones, perhaps reflecting slower gains in efficiency of neural processing. These results complement those of Hill and Shen (2002) who, examining neurodevelopmental patterns of change in P300 amplitude from age 9–14, also found that trajectories of P300 amplitude varied with familial risk. Offspring with both an alcoholic father and uncle were considered at high risk, and these children were disproportionately represented in a P300 trajectory group characterized by smaller P300 overall and a slow rate of change from age 9 to 14.
