Toward Scalable Mental Health Screening: Gender-Sensitive Biomarkers from Portable Prefrontal EEG Devices

Background: Major depressive disorder (MDD) is a prevalent mental health condition associated with substantial emotional and functional impairment. While interest in neurophysiological markers is growing, gender-specific neural oscillatory patterns measured by portable EEG devices remain underexplored. Objective: This study examined whether relative spectral power in the high alpha band (11–13 Hz), recorded by a three-channel prefrontal EEG device during eyes-closed resting state, is associated with emotional states and clinical diagnosis, with attention to gender differences. Methods: Forty participants (18 MDD patients, 22 healthy controls; 22 females) from the MODMA dataset completed EEG recordings using both a 128-channel laboratory system and a portable three-channel device (Fp1, Fpz, Fp2). Emotional status was assessed using PHQ-9, GAD-7, and CTQ-SF. Pearson correlations were conducted between spectral power (4–20 Hz) and emotional scale scores. Results: Spectral features from the portable EEG closely matched those of the lab system (r = 0.975). High alpha power positively correlated with all three scales, especially in females, where associations extended into the low beta range. At 11.9 Hz, PHQ-9 correlations were significant for both males (r = 0.40, p = 0.011) and females (r = 0.33, p = 0.037). High alpha power also distinguished MDD from controls (r = 0.32, p = 0.042), independent of age and education. Conclusion: Frontal high alpha activity measured by a portable EEG device is a promising neural marker of emotional dysregulation, with stronger and broader associations observed in females. These findings support gender-sensitive EEG-based screening approaches for mood disorders in community and clinical settings.