P.2.f.002 The effect of EEG biofeedback on electrophysiological disturbances and symptoms in patients with depressive disorder

Abstract

Background and Purpose: In EEG studies of depression, an abnormal pattern of asymmetric activity in the frontal regions from relative hyperactivity over the right frontal regions and/or relative hypoactivity over the left frontal regions has frequently been observed [1]. It has been suggested that EEG biofeedback could contribute normalization of EEG activity in depressed patient safely [2]. According to the recent paper [3], 21 clinical studies reported on EEG biofeedback treatment in patients with depressive disorders, and there have been only six original articles. The purpose of this study was to evaluate the effect of EEG biofeedback on electrophysiological disturbances and depressive symptoms in patient with depressive disorders. Method: 20 participants were recruited from July, 2009 to July, 2012 in a university hospital. Treatment protocol was twice or three times a week training of left hemisphere beta at F3 with alpha/theta training at Pz for 8 weeks. The neurocybernetics model of neurocybernetics company was used for EEG biofeedback training. In beta training, the reward band ranged from 15Hz to 18Hz. In alpha-theta training, the patients were trained to reduce the alpha level above 12 mV (peak-to-peak) while augmenting theta. The theta (5Hz-8Hz) and alpha (8Hz-12Hz) were reward bands. EEG was recorded by a complexity ver 2 of LAXTHA at 8 scalp locations according to the international 10/20 system. All placements were referenced to A1 or A2. We compared baseline and 8 week scores of Hamilton rating scale for Depression (HAM-D), Hamilton rating scale for Anxiety (HAM-A), Clinical global impression-severity (CGI-S) and we also compared before and after treatment resting state EEG. Interhemispheric alpha power asymmetry, called A score, was computed for homologous sites F3-F4. An asymmetry metric (A score) was computed for each epoch by subtracting logtransformed alpha power of the left midfrontal site from logtransformed alpha power of the right site (logR − log L). Negative A score means more depressed state. Results: Pre and post training clinical assessment reveals that there were significant improvement in HAM-D (p< 0.01), HAM-A (p< 0.01) and CGI-S score (p< 0.01). Asymmetry scores increased after training. In other words the negativity decreased after training. As alpha power inversely correlates with the activity of the corresponding brain area and the increase in the asymmetry score meant relative dominance on the left frontal area. But it was not statistically significant. Conclusion: EEG biofeedback treatment could improve depressive symptoms significantly. Also anxiety symptoms and functional impairment decreased after EEG biofeedback treatment. There are several limitations of this study such as small sample size, lack of control group. But this study demonstrates the significant effects of EEG Biofeedback in objective & subjective rating scales for adult patients with depressive disorders. Double blinded large controlled studies are needed in the future.