Spaced Transcranial Direct Current Stimulation for Major Depression
Maxime Couture, Véronique Desbeaumes Jodoin, Emma Bousseau, Arash Sarshoghi, Michael A. Nitsche, Daniel M. Blumberger, Chantal Bolduc, Cory R. Weissman, Lawrence G. Appelbaum, Zafiris J. Daskalakis, Mohsen Poorganji, Paul Lespérance, Jean‐Philippe Miron
Abstract
OBJECTIVE: This study investigated spaced transcranial direct current stimulation for major depressive disorder, focusing on feasibility. METHODS: In a prospective open-label study, 30 participants with major depressive disorder were enrolled to receive a 50-session transcranial direct current stimulation (tDCS) treatment over 2 weeks. The feasibility, safety, tolerability, and preliminary therapeutic effects of this tDCS protocol were assessed using the 17-item Hamilton Depression Rating Scale (HAM-D-17) and the Montgomery-Åsberg Depression Rating Scale (MADRS) at baseline and 1-week and 4-week follow-ups, as well as with the 6-item HAM-D (HAM-D-6) daily during treatment. RESULTS: The protocol demonstrated good feasibility, with a retention rate of 93.3% and an adherence rate of 99.7%. There were no serious adverse events. The most common side effect was a mild tingling and itching sensation during stimulation (100%) and temporary skin redness following stimulation (100%). Additionally, 64.3% of participants presented with mild irritative contact dermatitis, which had disappeared by the 1-week follow-up for most participants and completely resolved by the 4-week follow-up for the remaining cases; this was not treatment limiting and did not require specific treatment. HAM-D-17 scores decreased from a mean of 21.3 (SD=3.0) at baseline to 15.3 (SD=6.3) at 1 week and 13.2 (SD=7.1) at 4 weeks. Depressive symptom severity, as measured by the HAM-D-17, showed significant reductions over time, with similar trends observed on the MADRS. HAM-D-6 scores highlighted important differences between response groups, particularly during the later stages of treatment, suggesting a potential for differential response patterns between the 1-week and 4-week follow-ups. CONCLUSIONS: The protocol was feasible, safe, and well-tolerated and led to significant reductions in depressive symptoms. These results will need to be validated in a sham-controlled randomized trial. The inclusion of neurophysiological measures in future trials for purposes of biological target engagement might also contribute to our understanding of underlying mechanisms and biomarker discovery.