Background: The P300 component of the event-related potential has been exte
nsively studied as a possible neurobiological risk marker for the developme
nt of alcoholism. Although P300 amplitude reduction has frequently been doc
umented in high-risk children, studies of adult alcoholics are inconsistent
.
Methods: P300 amplitude from 121 adult alcoholics was compared to 68 contro
ls utilizing event-related potential paradigms from the auditory and visual
modalities. All participants were evaluated clinically with psychiatric in
terviews and administered the MMPI.
Results: Male alcoholics did not show a reduction in amplitude in either th
e auditory or visual modality. Female alcoholics showed reduced P300 amplit
ude, but only when a comorbid lifetime diagnosis of depression was present.
Similar results were found using current depressed mood (Scale 2 from the
MMPI),
Conclusions: No differences in P300 amplitude were found between alcoholics
and controls unless comorbid depression was present. Therefore, P300 ampli
tude reduction seen in children at high-risk for developing alcoholism seem
s to represent a neurodevelopmental delay that normalizes by adulthood. Bio
l Psychiatry 1999;46: 982-989 (C) 1999 Society of Biological Psychiatry.