title: Default-mode and task-positive network activity in major depressive disorder: implications for adaptive and maladaptive rumination.
abstract: BACKGROUND
  Major depressive disorder (MDD) has been associated reliably with ruminative responding; this kind of responding is composed of both maladaptive and adaptive components. Levels of activity in the default-mode network (DMN) relative to the task-positive network (TPN), as well as activity in structures that influence DMN and TPN functioning, may represent important neural substrates of maladaptive and adaptive rumination in MDD.
  
  
  METHODS
  We used a unique metric to estimate DMN dominance over TPN from blood oxygenation level-dependent data collected during eyes-closed rest in 17 currently depressed and 17 never-disordered adults. We calculated correlations between this metric of DMN dominance over TPN and the depressive, brooding, and reflective subscales of the Ruminative Responses Scale, correcting for associations between these measures both with one another and with severity of depression. Finally, we estimated and compared across groups right fronto-insular cortex (RFIC) response during initiations of ascent in DMN and in TPN activity.
  
  
  RESULTS
  In the MDD participants, increasing levels of DMN dominance were associated with higher levels of maladaptive, depressive rumination and lower levels of adaptive, reflective rumination. Moreover, our RFIC state-change analysis showed increased RFIC activation in the MDD participants at the onset of increases in TPN activity; conversely, healthy control participants exhibited increased RFIC response at the onset of increases in DMN activity.
  
  
  CONCLUSIONS
  These findings support a formulation in which the DMN undergirds representation of negative, self-referential information in depression, and the RFIC, when prompted by increased levels of DMN activity, initiates an adaptive engagement of the TPN.
authors: Department of Psychology, Stanford University, Stanford, California 94305, USA. paul.hamilton@stanford.edu
authors: J Paul
authors: JP
authors: Hamilton
authors: Daniella J
authors: DJ
authors: Furman
authors: Catie
authors: C
authors: Chang
authors: Moriah E
authors: ME
authors: Thomason
authors: Emily
authors: E
authors: Dennis
authors: Ian H
authors: IH
authors: Gotlib
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D001921:Brain / Q000098:blood supply / Q000473:pathology*; D001931:Brain Mapping; D003865:Major Depressive Disorder / Q000473:pathology* / Q000523:psychology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000473:pathology; D010100:Oxygen / Q000097:blood; D011569:Psychiatric Status Rating Scales; D013223:Statistics as Topic; D013850:Thinking; D055815:Young Adult
chemical_list: D010100:Oxygen