Region-Specific Delta and Alpha2 Relative Power Alterations in Male Adolescent Schizophrenia: Occipital Predominance in Resting-State EEG

Resting-state electroencephalography (EEG) studies consistently report increased slow-wave activity and reduced alpha power in schizophrenia. However, the regional distribution of EEG relative power (RP) across finer frequency bands, particularly in adolescent schizophrenia, remains poorly characterized. We analyzed a publicly available resting-state EEG dataset comprising 45 male adolescents with schizophrenia (SCZ; mean age: 12.3 ± 1.2 years) and 39 age- and sex-matched healthy controls (CON; mean age: 12.3 ± 1.3years), recorded using 16 scalp electrodes (10–20 system). Following band-pass filtering, artefact subspace reconstruction, spline interpolation, average re-referencing and independent component analysis, RP was computed for nine frequency bands across five cortical regions (frontal, central, parietal, temporal, and occipital). Group differences were assessed using three-way repeated-measures analysis of variance (ANOVA), followed by Bonferroni false discovery rate (FDR)-corrected post-hoc pairwise comparisons using estimated marginal means (emmeans). Compared to controls, the SCZ group showed significantly higher delta RP in the frontal, parietal, and occipital regions and significantly lower alpha2 RP, dissociable from alpha1, in the central, parietal, temporal, and occipital regions (all FDR < 0.001). The occipital cortex showed the greatest increase in delta RP (|Cohen’s d |=0.82) and the greatest reduction in alpha2 RP (| d |=0.73), with moderate-to-large effect sizes. Topographic maps demonstrated widespread delta enhancement and attenuated occipito-parietal alpha2 activity in the SCZ group. These findings demonstrate region-specific alterations in resting-state EEG relative power in adolescent schizophrenia, particularly within the occipital cortex, and suggest that regional RP may serve as a promising neurophysiological feature for early-onset schizophrenia.