The present investigation was designed for the purpose of revealing functional brain impairments associated with alcoholism, anxiety and depression. The subjects were 56 women, with an average (SD) age of 34.8 (7.3) years. None reported a history of neurological or major medical disorders, or drug abuse. Twenty-nine of the women met DSM-IV lifetime criteria for a diagnosis of alcohol abuse or dependence. Twenty-five women reported mild or higher levels of anxiety, as indexed by a Beck Anxiety Inventory (BAI) score greater than 7. Electroencephalographic activity was recorded while subjects performed a visual ("oddball") selective attention task comprised of rare target, rare nontarget and frequent nontarget stimuli. P300 event-related potentials elicited by the rare target and rare nontarget stimuli were analyzed. The initial analysis was structured as a 2 (alcoholism) by 2 (anxiety) factorial. Analyses revealed no significant effects of alcoholism on P300. However, women reporting a BAI score greater than 7 exhibited significantly smaller P300 amplitudes than their nonanxious counterparts. The P300 decrement remained significant when depression level (Beck Depression Inventory [BDI-II]) and age were entered as covariates. A separate analysis was conducted in which the 56 subjects were classified by alcoholism and depression level (BDI-II score < or =13 vs >13). The analysis revealed no significant P300 differences associated with these factors. It is hypothesized that anxiety might play a role in mediating or amplifying the P300 decrements that have been attributed to alcoholism and depression in women. Additional and more comprehensive studies are needed to discern the validity ofthis hypothesis.