title: α Power, α asymmetry and anterior cingulate cortex activity in depressed males and females.
abstract: Left fronto-cortical hypoactivity, thought to reflect reduced activity in approach-related systems, and right parietal hypoactivity, associated with emotional under-arousal, have been noted in major depressive disorder (MDD). Altered theta activity in the anterior cingulate cortex (ACC) has also been associated with the disorder. We assessed resting frontal and parietal alpha asymmetry and power in non-medicated MDD (N = 53; 29 females) and control (N = 43; 23 females) individuals. Theta activity was examined using standardized low-resolution electromagnetic tomography (sLORETA) in the ACC [BA24ab and BA32 comprising the rostral ACC and BA25/subgenual (sg) ACC]. The MDD group, and particularly depressed males, displayed increased overall frontal and parietal alpha power and left midfrontal hypoactivity (alpha(2)-indexed). They also exhibited increased sgACC theta(2) activity. MDD females had increased right parietal activity, suggesting increased emotive arousal. Thus, unmedicated depressed adults were characterized by lower activity in regions implicated in approach/positive affective tendencies as well as diffuse cortical hypoarousal, though sex specific modulations emerged. Altered theta in the sgACC may reflect emotion regulation abnormalities in MDD.
authors.affiliation: University of Ottawa Institute of Mental Health Research, Ottawa, ON, Canada. Natalia.Jaworska@theroyal.ca
authors.forename: Natalia
authors.initials: N
authors.lastname: Jaworska
authors.forename: Pierre
authors.initials: P
authors.lastname: Blier
authors.forename: Wendy
authors.initials: W
authors.lastname: Fusee
authors.forename: Verner
authors.initials: V
authors.lastname: Knott
mesh_terms: D000328:Adult; D000513:Alpha Rhythm / Q000502:physiology*; D003865:Major Depressive Disorder / Q000503:physiopathology* / Q000523:psychology; D004569:Electroencephalography / Q000295:instrumentation / Q000379:methods; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006801:Humans; D008297:Male; D010296:Parietal Lobe / Q000503:physiopathology; D011569:Psychiatric Status Rating Scales; D012727:Sex Characteristics; D013826:Theta Rhythm / Q000502:physiology; D014054:Tomography / Q000295:instrumentation / Q000379:methods* / Q000523:psychology