title: Different associations of white matter lesions with depression and cognition.
abstract: BACKGROUND
  To test the hypothesis that white matter lesions (WML) are primarily associated with regional frontal cortical volumes, and to determine the mediating effects of these regional frontal cortices on the associations of WML with depressive symptoms and cognitive dysfunction.
  
  
  METHODS
  Structural brains MRIs were performed on 161 participants: cognitively normal, cognitive impaired but not demented, and demented participants. Lobar WML volumes, regional frontal cortical volumes, depressive symptom severity, and cognitive abilities were measured. Multiple linear regression analyses were used to identify WML volume effects on frontal cortical volume. Structural equation modeling was used to determine the MRI-depression and the MRI-cognition path relationships.
  
  
  RESULTS
  WML predicted frontal cortical volume, particularly in medial orbirtofrontal cortex, irrespective of age, gender, education, and group status. WML directly predicted depressive score, and this relationship was not mediated by regional frontal cortices. In contrast, the association between WML and cognitive function was indirect and mediated by regional frontal cortices.
  
  
  CONCLUSIONS
  These findings suggest that the neurobiological mechanisms underpinning depressive symptoms and cognitive dysfunction in older adults may differ.
authors.affiliation: Center for Imaging of Neurodegenerative Diseases, Veterans Affairs Medical Center, San Francisco, CA 94121, USA.
authors.forename: Jun-Young
authors.initials: JY
authors.lastname: Lee
authors.forename: Philip
authors.initials: P
authors.lastname: Insel
authors.forename: R Scott
authors.initials: RS
authors.lastname: Mackin
authors.forename: Norbert
authors.initials: N
authors.lastname: Schuff
authors.forename: Helena
authors.initials: H
authors.lastname: Chui
authors.forename: Charles
authors.initials: C
authors.lastname: DeCarli
authors.forename: Kee Hyung
authors.initials: KH
authors.lastname: Park
authors.forename: Susanne G
authors.initials: SG
authors.lastname: Mueller
authors.forename: Michael W
authors.initials: MW
authors.lastname: Weiner
mesh_terms: D002140:California / Q000453:epidemiology; D003072:Cognition Disorders / Q000453:epidemiology* / Q000473:pathology*; D015897:Comorbidity; D003863:Depression / Q000453:epidemiology* / Q000473:pathology*; D005260:Female; D006801:Humans; D015994:Incidence; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity