title: Specific functional connectivity alterations of the dorsal striatum in young people with depression.
abstract: BACKGROUND
  Altered basal ganglia function has been implicated in the pathophysiology of youth Major Depressive Disorder (MDD). Studies have generally focused on characterizing abnormalities in ventral "affective" corticostriatal loops supporting emotional processes. Recent evidence however, has implicated alterations in functional connectivity of dorsal "cognitive" corticostriatal loops in youth MDD. The contribution of dorsal versus ventral corticostriatal alterations to the pathophysiology of youth MDD remains unclear.
  
  
  METHODS
  Twenty-one medication-free patients with moderate-to-severe MDD between the ages of 15 and 24 years old were matched with 21 healthy control participants. Using resting-state functional connectivity magnetic resonance imaging we systematically investigated connectivity of eight dorsal and ventral subdivisions of the striatum. Voxelwise statistical maps of each subregion's connectivity with other brain areas were compared between the depressed and control groups.
  
  
  RESULTS
  Depressed youths showed alterations in functional connectivity that were confined to the dorsal corticostriatal circuit. Compared to controls, depressed patients showed increased connectivity between the dorsal caudate nucleus and ventrolateral prefrontal cortex bilaterally. Increased depression severity correlated with the magnitude of dorsal caudate connectivity with the right dorsolateral prefrontal cortex. There were no significant between-group differences in connectivity of ventral striatal regions.
  
  
  CONCLUSIONS
  The results provide evidence that alterations in corticostriatal connectivity are evident at the early stages of the illness and are not a result of antidepressant treatment. Increased connectivity between the dorsal caudate, which is usually associated with cognitive processes, and the more affectively related ventrolateral prefrontal cortex may reflect a compensatory mechanism for dysfunctional cognitive-emotional processing in youth depression.
authors.affiliation: Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Melbourne, Australia.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Kerestes
authors.affiliation: Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Melbourne, Australia.
authors.forename: Ben J
authors.initials: BJ
authors.lastname: Harrison
authors.affiliation: Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Melbourne, Australia.
authors.forename: Orwa
authors.initials: O
authors.lastname: Dandash
authors.affiliation: Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Melbourne, Australia.
authors.forename: Katerina
authors.initials: K
authors.lastname: Stephanou
authors.affiliation: Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Melbourne, Australia.
authors.forename: Sarah
authors.initials: S
authors.lastname: Whittle
authors.affiliation: MRI Research Unit, CRC Mar, Hospital del Mar, Barcelona, Spain ; Centro Investigación Biomédica en Red de Salud Mental, CIBERSAM G21, Barcelona, Spain.
authors.forename: Jesus
authors.initials: J
authors.lastname: Pujol
authors.affiliation: Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Melbourne, Australia ; Orygen Youth Health Research Centre, The University of Melbourne, Melbourne, Australia.
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Davey
mesh_terms: D000293:Adolescent; D003342:Corpus Striatum / Q000503:physiopathology*; D003865:Major Depressive Disorder / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000503:physiopathology*; D055815:Young Adult
keywords: Functional connectivity; Functional magnetic resonance imaging; Major Depressive Disorder; Striatum; Youth