Electrodermal Activity During Emotional Visual Stimuli in Adolescent Major Depressive Disorder: Time, Spectral, and Nonlinear Analysis

Abstract Background Adolescents with major depressive disorder (MDD) are associated with significant emotional dysregulation, yet objective physiological biomarkers remain elusive. While traditional electrodermal activity (EDA) measures provide a window into sympathetic arousal, the utility of spectral and nonlinear EDA analysis in characterizing adolescents with MDD is not well explored. Objective This study aimed to evaluate sympathetic reactivity in adolescents with MDD by comprehensive EDA analysis (time-domain, spectral, and nonlinear) during emotional visual stimuli. Methods We examined 61 drug-naïve adolescents with MDD and 52 age-matched healthy controls. EDA was recorded during five-periods protocol: baseline, positive visual stimuli, recovery 1, negative visual stimuli, and recovery 2. Analysis included EDA time (skin conductance level (SCL), non-specific skin conductance responses), spectral (power spectral densities for frequency bands ranged between 0.0 and 0.50 Hz), and nonlinear (approximate and sample entropy, detrending fluctuation analysis) parameters. Associations between EDA indices and State Anxiety were determined. Results Within-group comparisons revealed significantly higher SCL and spectral EDA indices during negative than positive stimuli in MDD group. In contrast, control group showed higher sympathetic arousal during positive than negative stimuli. Next, significant correlation between EDA indices and anxiety scores was observed exclusively in MDD group. Conclusion Our findings found differential modulation of the sympathetic nervous system activity during positive- and negative-valence emotional stimulation in MDD and control adolescents. Study proposes the potential of particularly spectral EDA measures as sensitive biomarkers for reactive sympathetic dysregulation in MDD group, where internal emotional states – specifically anxiety – can strongly influence emotion evoked sympathetic neural activation.