title: Reconciling variable findings of white matter integrity in major depressive disorder.
abstract: Diffusion tensor imaging (DTI) has been used to evaluate white matter (WM) integrity in major depressive disorder (MDD), with several studies reporting differences between depressed patients and controls. However, these findings are variable and taken from relatively small studies often using suboptimal analytic approaches. The presented DTI study examined WM integrity in large samples of medication-free MDD patients (n=134) and healthy controls (n=54) using voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) approaches, and rigorous statistical thresholds. Compared with health control subjects, MDD patients show no significant differences in fractional anisotropy, radial diffusivity, mean diffusivity, and axonal diffusivity with either the VBM or the TBSS approach. Our findings suggest that disrupted WM integrity does not have a major role in the neurobiology of MDD in this relatively large study using optimal imaging acquisition and analysis; however, this does not eliminate the possibility that certain patient subgroups show WM disruption associated with depression.
authors.affiliation: 1] Department of Psychiatry, Emory University, Atlanta, GA, USA [2] The Wallace H Coulter, Department of Biomedical Engineering, Biomedical, Imaging Technology Center, Georgia Institute of Technology, Emory University, Atlanta, GA, USA.
authors.forename: Ki Sueng
authors.initials: KS
authors.lastname: Choi
authors.affiliation: 1] Department of Psychiatry, Emory University, Atlanta, GA, USA [2] Departments of Psychiatry and Surgery, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Holtzheimer
authors.affiliation: Department of Electrical Engineering, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Alexandre R
authors.initials: AR
authors.lastname: Franco
authors.affiliation: Department of Biostatistics and Bioinformatics, Emory University, Atlanta, GA, USA.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Kelley
authors.affiliation: Department of Psychiatry, Emory University, Atlanta, GA, USA.
authors.forename: Boadie W
authors.initials: BW
authors.lastname: Dunlop
authors.affiliation: The Wallace H Coulter, Department of Biomedical Engineering, Biomedical, Imaging Technology Center, Georgia Institute of Technology, Emory University, Atlanta, GA, USA.
authors.forename: Xiaoping P
authors.initials: XP
authors.lastname: Hu
authors.affiliation: 1] Department of Psychiatry, Emory University, Atlanta, GA, USA [2] Department of Neurology, Emory University, Atlanta, GA, USA.
authors.forename: Helen S
authors.initials: HS
authors.lastname: Mayberg
mesh_terms: D000328:Adult; D016880:Anisotropy; D001369:Axons / Q000473:pathology; D001921:Brain / Q000473:pathology*; D003865:Major Depressive Disorder / Q000473:pathology*; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology*