The present investigation is a direct extension of Iacono et al. (2002), in which we demonstrated an association between P3-AR and specific externalizing spectrum disorders (Iacono et al., 2002; also see Patrick et al., 2006). The present study extends the P3 findings of Iacono et al. by using the same subjects to examine the association between the TF components and P3 amplitude in individuals diagnosed with any one of six disorders falling in this spectrum. This is the first study employing the TF-PCA method to examine these relationships, and to do so using a population-based sample, thus allowing greater generalizability of the findings. Probit regression was used to determine the abilities of P3 amplitude and each TF component’s amplitude to differentiate adolescent males with an externalizing disorder from those with no disorder. It was hypothesized that TF components would show reduced amplitude in externalizing disorders compared to a control group. Further, these components would be able to independently differentiate the two groups by accounting for unique variance above and beyond that accounted for by P3 amplitude.
