title: State-dependent altered connectivity in late-life depression: a functional near-infrared spectroscopy study.
abstract: There is a large body of evidence showing a substantial relationship between depression and deficits in cognitive functioning. Especially in late-life depression, cognitive impairments are associated with worse treatment progress and are considered a risk factor for neurodegenerative disorders. However, little is known about the differences in neural processing and coupling during rest and cognitive functions in patients with late-life depression compared to healthy elderly individuals. The study at hand aims to investigate the cognitive control network in late-life depression during a cognitive task and at rest by means of functional near-infrared spectroscopy. Hemodynamic responses were measured at rest and during the Trail Making Test using functional near-infrared spectroscopy in a matched sample of 49 depressed and 51 nondepressed elderly subjects (age range: 51-83 years; 64.1 ± 6.58 [mean ± standard deviation]). Functional connectivity (FC) and network metrics were derived from the data and analyzed with respect to differences between the subject groups. Depressed and nondepressed subjects showed significant differences in FC both at rest and during task performance. Depressed subjects showed reduced FC in a left frontopolar cortical network during task performance and increased FC in a left frontoparietal cortical network at rest. Depressed elderly subjects showed altered FC and network organization during different mental states. Higher FC at rest may be an indicator of self-referential processes such as rumination that may reduce FC during task performance due to an overtaxed executive control system.
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital of Tuebingen, Tuebingen, Germany. Electronic address: david.rosenbaum@med.uni-tuebingen.de.
authors.forename: David
authors.initials: D
authors.lastname: Rosenbaum
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital of Tuebingen, Tuebingen, Germany; German Center for Neurodegenerative Diseases (DZNE), Tuebingen, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Hagen
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital of Tuebingen, Tuebingen, Germany.
authors.forename: Saskia
authors.initials: S
authors.lastname: Deppermann
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital of Tuebingen, Tuebingen, Germany.
authors.forename: Agnes M
authors.initials: AM
authors.lastname: Kroczek
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital of Tuebingen, Tuebingen, Germany.
authors.forename: Florian B
authors.initials: FB
authors.lastname: Haeussinger
authors.affiliation: Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, Tuebingen, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Heinzel
authors.affiliation: Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, Tuebingen, Germany; German Center for Neurodegenerative Diseases (DZNE), Tuebingen, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Berg
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital of Tuebingen, Tuebingen, Germany; Center of Integrative Neuroscience (CIN), Cluster of Excellence, University of Tuebingen, Germany.
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Fallgatter
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital of Tuebingen, Tuebingen, Germany.
authors.forename: Florian G
authors.initials: FG
authors.lastname: Metzger
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital of Tuebingen, Tuebingen, Germany.
authors.forename: Ann-Christine
authors.initials: AC
authors.lastname: Ehlis
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003071:Cognition; D003863:Depression / Q000150:complications / Q000503:physiopathology* / Q000523:psychology*; D018450:Disease Progression; D056344:Executive Function; D005260:Female; D006439:Hemodynamics; D006801:Humans; D000067562:Late Onset Disorders; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology; D019636:Neurodegenerative Diseases / Q000209:etiology; D011597:Psychomotor Performance; D012146:Rest / Q000502:physiology; D012307:Risk Factors; D019265:Spectroscopy, Near-Infrared
keywords: Cognitive control network; Executive functioning; Functional connectivity; Late-life depression; Near-infrared spectroscopy; Network analysis