title: Magnetic resonance imaging in late-life depression: vascular and glucocorticoid cascade hypotheses.
abstract: BACKGROUND
  Late-life depression is a common and heterogeneous illness, associated with structural abnormalities in both grey and white matter.
  
  
  OBJECTIVE
  To examine the relationship between age at onset and magnetic resonance imaging (MRI) measures of grey and white matter to establish whether they support particular hypotheses regarding the anatomy and aetiology of network disruption in late-life depression.
  
  
  METHODS
  We studied 36 participants with late-life depression. Grey matter was examined using T(1)-weighted MRI and analysed using voxel-based morphometry. The hippocampus was automatically segmented and volume and shape analysis performed. White matter was examined using diffusion tensor imaging and analysed using tract-based spatial statistics.
  
  
  RESULTS
  Later age at onset was significantly associated with reduced fractional anisotropy of widespread tracts, in particular the anterior thalamic radiation and superior longitudinal fasciculus. Earlier age at onset was associated with reduced hippocampal volume normalised to whole brain size bilaterally. However, no significant correlations were detected using hippocampal shape analysis or voxel-based morphometry.
  
  
  CONCLUSIONS
  Overall, the results were compatible with the vascular hypothesis, and provided some support for the glucocorticoid cascade hypothesis.
authors: University Department of Psychiatry, Warneford Hospital, Oxford, UK.
authors: Claire E
authors: CE
authors: Sexton
authors: Marisa
authors: M
authors: Le Masurier
authors: Charlotte L
authors: CL
authors: Allan
authors: Mark
authors: M
authors: Jenkinson
authors: Lisa
authors: L
authors: McDermott
authors: Ukwuori G
authors: UG
authors: Kalu
authors: Lucie L
authors: LL
authors: Herrmann
authors: Kevin M
authors: KM
authors: Bradley
authors: Clare E
authors: CE
authors: Mackay
authors: Klaus P
authors: KP
authors: Ebmeier
mesh_terms: D017668:Age of Onset; D000368:Aged; D001927:Brain Diseases / Q000473:pathology*; D002561:Cerebrovascular Disorders / Q000473:pathology; D003866:Depressive Disorder / Q000473:pathology*; D005260:Female; D005938:Glucocorticoids / Q000502:physiology*; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D056784:Leukoencephalopathies / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009929:Organ Size
chemical_list: D005938:Glucocorticoids