Frontal Alpha Asymmetry Correlates with Suicidal Behavior in Major Depressive Disorder
Yeonsoo Park 1, Wookyoung Jung 2, Sungkean Kim 1, 3, Hyunjin Jeon 1, Seung-Hwan Lee 1, 4*
1Clinical Emotion and Cognition Research Laboratory, Department of Psychiatry, Inje University, Goyang, Korea, 2Department of Psychology, Keimyung University, Daegu, Korea, 3Department of Biomedical Engineering, Hanyang University, Seoul, Korea, 4Department of Psychiatry, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea
Received: April 9, 2018; Revised: May 30, 2018; Accepted: June 28, 2018; Published online: June 28, 2018.
© The Korean College of Neuropsychopharmacology. All rights reserved.

Objective: Based on the constant associations made between major depressive disorder (MDD) and alpha asymmetry, and MDD and suicide, this study aimed to examine the relationship between frontal alpha asymmetry and suicide in MDD patients.
Methods: Sixty-six MDD patients, of whom fifteen were male and fifty-one were female, were recruited. Independent groups were created based on the median score of frontal alpha asymmetry: the left dominant group (LD) and the right dominant group (RD). The alpha band (8-12 Hz) and its sub-bands (i.e., low alpha band: 8-10 Hz; high alpha band: 10-12 Hz) were of interest. Source level alpha asymmetry was calculated as well.
Results: Suicidal behavior was positively correlated with the asymmetry indices of the low alpha band and the alpha band in the LD group and that of the high alpha band in the RD group. Source level analysis revealed positive correlations between suicidal behavior and the asymmetry index of the low alpha band in the LD group.
Conclusions: Frontal alpha asymmetry, especially that of the low alpha band, might reflect the cognitive deficits associated with suicidal behaviors in MDD patients.
Keywords: Alpha asymmetry, Depression, Suicide, qEEG