Abstract
OBJECTIVE: To assess how Peak Alpha Frequency (PAF) as a neurophysiological biomarker of pain sensitivity is influenced by conditions often comorbid with chronic pain, e.g., depression, and how methodological differences in deriving PAF, e.g., from Eyes-open (EO) vs. Eyes-closed (EC) EEG recordings affect this association. METHODS: We analyzed data from 47 participants (70 % female) aged 18-51 years (M = 25.0, SD = 6.50). Among them, all participants underwent EO EEG recording but only a subset of 25 participants underwent both EO and EC recording. Depression (Patient Health Quotient - 9 M = 4.49, SD = 3.96) and sensitivity to heat pain were measured. RESULTS: In EO, Spearman correlations showed no significant PAF-pain relationship (p = 0.530) but a positive correlation with depression (ρ = 0.348, p = 0.019). In EC, no significant correlations emerged, though a trend (p = 0.052) suggested depression might moderate PAF-pain links. Notably, the EO-EC PAF difference negatively correlated with depression (ρ = -0.54, p < 0.01). CONCLUSIONS: PAF may be sensitive to depression, albeit in the opposite direction to pain, and therefore mask the association between PAF and pain in individuals with depression. Differences in EO vs. EC PAF, as well as the EO-EC difference warrant further study. SIGNIFICANCE: Depression affects PAF especially in the eyes-open recordings.