Electroencephalographic Alpha Asymmetry in Major Depressive Disorder Patients With Anxiety Symptoms

불안을 동반한 주요우울장애 환자에 대한 뇌파 알파 비대칭의 특성 연구

Objectives : Studies have reported differences between depressed adults and controls in quantitative measures of EEG alpha asymmetry, but, there are few using Korean subjects. So, the present study compared EEG regional alpha asymmetries of patients having major depressive disorder(MDD) and normal controls. Methods : The subjects in this study were 11 unmedicated unipolar depressed patients and 11 non-depressed, age matched controls. Resting EEG(eyes closed and eyes open) was recorded from each participant using 8 scalp electrodes. Beck Depression Inventory(BDI), 17-item Hamilton Depression Rating Scale(HDRS), Zung's Self-Rating Depression Scale(SDS) and Spielberger's State-Trait Anxiety Inventory(STAI) were used to evaluate depression and anxiety symptoms. Results : The severities of depression measured by self-report questionnaires were positively associated with those of anxiety(state and trait) ; The subjects were both anxious and depressed. Anxious-depressed patients differed from controls in alpha asymmetry at T4 channels. They showed evidence of greater activation over right than left temporal site. Conclusion : These findings are consistent with the previousely reported alpha asymmetry of depressed patients with an anxiety disorder. The failure to find the evidence of reduced right parietal activity in depression is presumed to be due to opposing effects of comorbid anxiety on parietotemporal activity.