title: The salience network in the apathy of late-life depression.
abstract: OBJECTIVE
  Apathy is prevalent in late-life depression and predicts poor response to antidepressants, chronicity of depression, disability, and greater burden to caregivers. However, little is known about its neurobiology. Salience processing provides motivational context to stimuli. The aim of this study was to examine the salience network (SN) resting-state functional connectivity (rsFC) pattern in elderly depressed subjects with and without apathy.
  
  
  METHODS
  Resting-state functional MRI data were collected from 16 non-demented, non-MCI, elderly depressed subjects and 10 normal elderly subjects who were psychotropic-free for at least 2 weeks. The depressed group included 7 elderly, depressed subjects with high comorbid apathy and 9 with low apathy. We analyzed the rsFC patterns of the right anterior insular cortex (rAI), a primary node of the SN.
  
  
  RESULTS
  Relative to non-apathetic depressed elderly, depressed elderly subjects with high apathy had decreased rsFC of the rAI to dorsal anterior cingulate and to subcortical/limbic components of the SN. Depressed elderly subjects with high apathy also exhibited increased rsFC of the rAI to right dorsolateral prefrontal cortex and right posterior cingulate cortex when compared to non-apathetic depressed elderly.
  
  
  CONCLUSIONS
  Elderly depressed subjects with high apathy display decreased intrinsic rsFC of the SN and an altered pattern of SN rsFC to the right DLPFC node of the central executive network when compared to elderly non-apathetic depressed and normal, elderly subjects. These results suggest a unique biological signature of the apathy of late-life depression and may implicate a role for the rAI and SN in motivated behavior.
authors.affiliation: Weill Medical College of Cornell University, Weill Cornell Institute of Geriatric Psychiatry, NY, USA.
authors.forename: Genevieve S
authors.initials: GS
authors.lastname: Yuen
authors.forename: Faith M
authors.initials: FM
authors.lastname: Gunning-Dixon
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Hoptman
authors.forename: Bassem
authors.initials: B
authors.lastname: AbdelMalak
authors.forename: Amanda R
authors.initials: AR
authors.lastname: McGovern
authors.forename: Joanna K
authors.initials: JK
authors.lastname: Seirup
authors.forename: George S
authors.initials: GS
authors.lastname: Alexopoulos
mesh_terms: D017668:Age of Onset; D000368:Aged; D057565:Apathy / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000502:physiology*; D003866:Depressive Disorder / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000503:physiopathology
keywords: aging; amotivation; apathy; atypical depression; geriatric; insula; salience