Event-related potentials in alcoholics and their first-degree relatives.

Preliminary results are presented for auditory ERPs recorded from members of alcoholic families during performance of a counting task and a choice reaction task. Alcoholic families included three adult male siblings (alcoholic proband, a second affected sib, and an unaffected sib) and parents. Control families included two adult male sibs and parents. In all experimental conditions, the N100 component was decreased in amplitude for all sibs (affected and unaffected) of the alcoholic families. The latency of the P300 component was increased for both affected and unaffected sibs compared to controls in the counting task, indicating a familial difference irrespective of drinking status. In the choice reaction task, longer P300 latencies were observed among the probands and their affected sibs as compared to their unaffected sibs, suggesting that in this more demanding task, increased latency was associated with a significant drinking history. ERP findings for children of the alcoholic probands are also discussed. The effects of differences in task complexity, drinking variables, and criteria for family selection are considered.