Electroencephalographic frontal asymmetry and depressive symptoms in the elderly.

Although neurophysiological changes of aging are well known, there is still much to learn about cortical asymmetry in older depressed subjects. This study aimed at assessing differences between depressed and normal elderly subjects on alpha asymmetry, and to observe the correlations of this measure with depressive symptoms and quality of life. Thirty-six subjects (14 normal and 22 depressed) were assessed by EEG, depression rating scales, and SF-36. Despite the fact that compared to healthy elderly, depressive elderly subjects showed relatively greater right frontal activity (F4F3) and relatively greater left parietal activity (P4P3); this difference was not significant. The relationship between depression and frontal asymmetry was better observed in healthy elderly, where relatively greater left frontal activity was associated with less depressive symptoms.