title: Frontal white matter integrity is related to psychomotor retardation in major depression.
abstract: Altered frontal white matter integrity has been reported in major depression. Still, the behavioral correlates of these alterations are not established. In healthy subjects, motor activity correlated with white matter integrity in the motor system. To explore the relation of white matter integrity and motor activity in major depressive disorder, we investigated 21 medicated patients with major depressive disorder and 21 matched controls using diffusion tensor imaging and wrist actigraphy at the same day. Patients had lower activity levels (AL) compared with controls. Fractional anisotropy (FA) differed between groups in frontal white matter regions and the posterior cingulum. AL was linearly associated with white matter integrity in two clusters within the motor system. Controls had an exclusive positive association of FA and AL in white matter underneath the right dorsal premotor cortex. Only patients had a positive association within the posterior cingulum. Furthermore, patients had negative associations of FA and AL underneath the left primary motor cortex and within the left parahippocampal gyrus white matter. These differences in the associations between structure and behavior may contribute to well-known impaired motor planning or gait disturbances in major depressive disorder. Therefore, signs of psychomotor slowing in major depressive disorder may be linked to changes of the white matter integrity of the motor system.
authors.affiliation: University Hospital of Psychiatry, University of Bern, Bolligenstrasse 111, 3000 Bern 60, Switzerland. walther@puk.unibe.ch
authors.forename: Sebastian
authors.initials: S
authors.lastname: Walther
authors.forename: Simone
authors.initials: S
authors.lastname: Hügli
authors.forename: Oliver
authors.initials: O
authors.lastname: Höfle
authors.forename: Andrea
authors.initials: A
authors.lastname: Federspiel
authors.forename: Helge
authors.initials: H
authors.lastname: Horn
authors.forename: Tobias
authors.initials: T
authors.lastname: Bracht
authors.forename: Roland
authors.initials: R
authors.lastname: Wiest
authors.forename: Werner
authors.initials: W
authors.lastname: Strik
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Müller
mesh_terms: D056044:Actigraphy; D000328:Adult; D016880:Anisotropy; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000150:complications / Q000473:pathology*; D056324:Diffusion Tensor Imaging; D005260:Female; D006179:Gyrus Cinguli / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009044:Motor Cortex / Q000473:pathology*; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D020534:Parahippocampal Gyrus / Q000473:pathology*; D011596:Psychomotor Disorders / Q000150:complications / Q000473:pathology*