Efficacy of transcranial photobiomodulation in the treatment for major depressive disorder: A TMS‐EEG and pilot study

• Published in: Photodermatology, photoimmunology & photomedicine Vol. 40; no. 2; pp. e12957 - n/a
• Main Authors: Hao, Wensi, Dai, Xiaona, Wei, Min, Li, Siran, Peng, Mao, Xue, Qing, Lin, Hua, Wang, Huicong, Song, Penghui, Wang, Yuping
• Format: Journal Article
• Language: English
• Published: England 01.03.2024
• Subjects: Depressive Disorder, Major - therapy; Electroencephalography; Humans; left frontal pole; Low-Level Light Therapy; major depressive disorder; Pilot Projects; time‐varying EEG network; TMS‐EEG; Transcranial Magnetic Stimulation; transcranial photobiomodulation; time-varying EEG network; transcranial photobiomodulation; TMS-EEG; left frontal pole; major depressive disorder
• ISSN: 0905-4383; 1600-0781
• DOI: 10.1111/phpp.12957

Background Major depressive disorder (MDD) was a prevalent mental condition that may be accompanied by decreased excitability of left frontal pole (FP) and abnormal brain connections. An 820 nm tPBM can induce an increase in stimulated cortical excitability. The purpose of our study was to establish how clinical symptoms and time‐varying brain network connectivity of MDD were affected by transcranial photobiomodulation (tPBM). Methods A total of 11 patients with MDD received 820 nm tPBM targeting the left FP for 14 consecutive days. The severity of symptoms was evaluated by neuropsychological assessments at baseline, after treatment, 4‐week and 8‐week follow‐up; 8‐min transcranial magnetic stimulation combined electroencephalography (TMS‐EEG) was performed for five healthy controls and five patients with MDD before and after treatment, and time‐varying EEG network was analyzed using the adaptive‐directed transfer function. Results All of scales scores in the 11 patients decreased significantly after 14‐day tPBM (p < .01) and remained at 8‐week follow‐up. The time‐varying brain network analysis suggested that the brain regions with enhanced connection information outflow in MDD became gradually more similar to healthy controls after treatment. Conclusions This study showed that tPBM of the left FP could improve symptoms of patients with MDD and normalize the abnormal network connections.