title: Persistent decrease in alpha current density in fully remitted subjects with major depressive disorder treated with fluoxetine: A prospective electric tomography study.
abstract: Major depressive disorder (MDD) is recurrent, and its pathophysiology is not fully understood. Studies using electric tomography (ET) have identified abnormalities in the current density (CD) of MDD subjects in regions associated with the neurobiology of MDD, such as the anterior cingulate cortex (ACC) and medial orbitofrontal cortex (mOFC). However, little is known regarding the long-term CD changes in MDD subjects who respond to antidepressants. The aim of this study was to compare CD between healthy and MDD subjects who received 1-year open-label treatment with fluoxetine. Thirty-two-channel electroencephalograms (EEGs) were collected from 70 healthy controls and 74 MDD subjects at baseline (pre-treatment), 1 and 2weeks and 1, 2, 6, 9 and 12months. Variable-resolution ET (VARETA) was used to assess the CD between subject groups at each time point. The MDD group exhibited decreased alpha CD (αCD) in the occipital and parietal cortices, ACC, mOFC, thalamus and caudate nucleus at each time point. The αCD abnormalities persisted in the MDD subjects despite their achieving full remission. The low sub-alpha band was different between the healthy and MDD subjects. Differences in the amount of αCD between sexes and treatment outcomes were observed. Lack of a placebo arm and the loss of depressed patients to follow-up were significant limitations. The persistence of the decrease in αCD might suggest that the underlying pathophysiologic mechanisms of MDD are not corrected despite the asymptomatic state of MDD subjects, which could be significant in understanding the highly recurrent nature of MDD.
authors.affiliation: Centro Estatal de Salud Mental, Servicios de Salud del Estado de Querétaro (SESEQ), Avenida 5 de Febrero 105, Los Virreyes, C.P. 76170 Querétaro, México. Electronic address: almeidal@prodigy.net.mx.
authors.forename: Luis Guillermo
authors.initials: LG
authors.lastname: Almeida Montes
authors.affiliation: Centro Estatal de Salud Mental, Servicios de Salud del Estado de Querétaro (SESEQ), Avenida 5 de Febrero 105, Los Virreyes, C.P. 76170 Querétaro, México.
authors.forename: Hugo
authors.initials: H
authors.lastname: Prado Alcántara
authors.affiliation: Centro Estatal de Salud Mental, Servicios de Salud del Estado de Querétaro (SESEQ), Avenida 5 de Febrero 105, Los Virreyes, C.P. 76170 Querétaro, México.
authors.forename: Bertha Alicia
authors.initials: BA
authors.lastname: Portillo Cedeño
authors.affiliation: Centro Estatal de Salud Mental, Servicios de Salud del Estado de Querétaro (SESEQ), Avenida 5 de Febrero 105, Los Virreyes, C.P. 76170 Querétaro, México.
authors.forename: Ana Olivia
authors.initials: AO
authors.lastname: Hernández García
authors.affiliation: Centro Estatal de Salud Mental, Servicios de Salud del Estado de Querétaro (SESEQ), Avenida 5 de Febrero 105, Los Virreyes, C.P. 76170 Querétaro, México.
authors.forename: Patricia Elisa
authors.initials: PE
authors.lastname: Fuentes Rojas
mesh_terms: D000293:Adolescent; D000328:Adult; D000513:Alpha Rhythm / Q000187:drug effects*; D018687:Antidepressive Agents, Second-Generation / Q000627:therapeutic use*; D001931:Brain Mapping; D016009:Chi-Square Distribution; D003865:Major Depressive Disorder / Q000188:drug therapy* / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D005473:Fluoxetine / Q000627:therapeutic use*; D005583:Fourier Analysis; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011446:Prospective Studies; D013997:Time Factors; D055815:Young Adult
chemical_list: D018687:Antidepressive Agents, Second-Generation; D005473:Fluoxetine
keywords: Alpha current density; Fluoxetine; Major depressive disorder; Remission; VARETA