Schedule of Events | Symposia

Investigating the Effects of tDCS on Autonomic Arousal in Major Depression: Insights from Electrodermal Activity

Poster Session D - Monday, March 31, 2025, 8:00 – 10:00 am EDT, Back Bay Ballroom/Republic Ballroom

Alexa Gorman¹ (alexamgorman@gmail.com), Alexandra E. Kelly¹, Evangelia G. Chrysikou¹; ¹Drexel University

Major depressive disorder (MDD) is characterized by impairments in emotion regulation and is often accompanied by dysregulated autonomic arousal. Transcranial direct current stimulation (tDCS) has emerged as a potential therapeutic intervention for MDD, yet its effects on physiological markers of emotional processing remain underexplored. In this study, we analyzed electrodermal activity (EDA) data collected during a combined fMRI-tDCS session to investigate the impact of unilateral anodal (excitatory) stimulation over the left prefrontal cortex (PFC) on EDA responses during an emotion regulation task. Nineteen MDD patients and seventeen age- and gender-matched healthy control participants completed a cognitive reappraisal task involving emotionally salient stimuli under sham and active tDCS over left PFC. The results indicated differential modulation of EDA between MDD patients and control participants, with MDD patients exhibiting a decrease in the number of skin conductance responses (SCR) and a significant decrease in the mean amplitude of SCR when receiving active (vs. sham) stimulation over left PFC. These findings provide insights into the relationship between cortical stimulation, autonomic arousal, and emotion regulation, highlighting the potential of EDA as a biomarker for assessing the efficacy of tDCS for PFC modulation in mood disorders. These results underscore the importance of integrating physiological measures in noninvasive brain stimulation studies to better understand the mechanisms underlying the therapeutic effects of tDCS in MDD and other neuropsychiatric disorders.

Topic Area: EMOTION & SOCIAL: Emotional responding