Identifying a multivariate endophenotype for substance use disorders usingpsychophysiological measures

This investigation examined how reduced amplitude of the P300 event-related potential (elicited from a visual oddball task) can be used together with an electrodermal response modulation measure (indexing the ability to inhib it responsivity to a temporally predictable aversive stimulus) to identify adolescents at especially high risk to develop substance dependence. One hu ndred and twenty-nine 17-year-old boys were divided into groups characteriz ed as low risk (high amplitude P300 and good electrodermal modulation), hig h risk (reduced amplitude P300 and poor modulation), or intermediate risk ( a high or good score on one measure and a low or poor score on the other). P300 amplitude and electrodermal modulation were uncorrelated. High-risk bu ys had 4-6 times more alcohol dependence than intermediate or low-risk buys and 2-3 times more nicotine dependence. Performance on an antisaccade eye- tracking task in which participants directed their gaze in a direction oppo site to target movement was related to electrodermal modulation but not P30 0 amplitude. The results from all three psychophysiological measures togeth er suggest that the neural circuits affecting P300 amplitude and electroder mal response modulation are different and that poor electrodermal response modulation may reflect an inhibitory control deficit mediated by the fronta l lobes. (C) 2000 Elsevier Science B.V. All rights reserved.