A Bayesian Classification Approach for Exploring EEG Band Power Reduction and P300 Attenuation as Candidate Group-Associated Markers in Alcohol Use Disorder: A Preliminary Study

Alcohol Use Disorder (AUD) is associated with widespread neurophysiological dysregulation, yet accessible and objective biomarkers for early risk identification remain limited. This preliminary study investigates electroencephalographic (EEG) frequency-domain and event-related potential features as candidate group-associated markers in AUD, with a focus on band power reduction and P300 event-related potential attenuation. Using the Begleiter EEG Database (UCI Machine Learning Repository, 1995), comprising 77 individuals with AUD and 45 healthy controls and recorded from 64 channels, we performed power spectral density estimation via Welch’s method and extracted band power across five frequency bands: delta (1–4 Hz), theta (4–8 Hz), alpha (8–13 Hz), beta (13–30 Hz), and gamma (30–50 Hz). Band power was computed at the trial level and averaged across trials at the subject level. Statistical comparisons using the Mann–Whitney U test with Benjamini–Hochberg FDR correction revealed significant band power reductions in the AUD group across frontal, central, and parietal channels, with the largest effects observed in parietal delta (P3: Hedges’ g=−0.97, q<0.0001; P4: g=−0.95, q<0.0001) and central theta (C4: g=−0.97, q<0.0001). P300 amplitude was significantly attenuated at parietal sites in S2 match (target) trials (Pz: g=−0.75, p=0.0002), consistent with hypothesised dopaminergic dysregulation of attentional processing networks. A Gaussian Naive Bayes classifier using the eight analysis channels selected for classification achieved a cross-validated ROC AUC = 0.713±0.088 [95% CI: 0.526, 0.833] under repeated stratified cross-validation, confirmed above chance by a permutation test (p=0.001). The complete analytical pipeline was executed on consumer-grade hardware without GPU acceleration, in line with Green AI principles. Topographic analysis indicated a spatially consistent parietal-dominant pattern of band power reduction. These findings suggest that task-evoked EEG frequency-domain and P300 features are systematically associated with AUD group membership and may warrant further investigation as candidate markers. The cross-sectional design of this study precludes conclusions regarding early risk identification, screening utility, or causal dopaminergic mechanisms; longitudinal validation in larger cohorts is required.