title: Impaired interhemispheric connectivity in medication-naive patients with major depressive disorder.
abstract: BACKGROUND
  Abnormalities in the anterior interhemispheric connections provided by the corpus callosum (CC) have long been implicated in major depressive disorder (MDD). The purpose of this study was to investigate interhemispheric connectivity in medication-naive patients with MDD by measuring fractional anisotropy in the CC with diffusion tensor imaging (DTI) techniques.
  
  
  METHODS
  We obtained DTI scans from medication-naive patients with MDD and from matched healthy controls. Fractional anisotropy values were compared using semiautomatic region of interest methods to localize the regional CC differences between these 2 groups.
  
  
  RESULTS
  We enrolled 27 patients and 27 controls in our study. Fractional anisotropy values were significantly lower in the anterior genu of the CC in the MDD group than in the control group (p = 0.009, corrected); results were not significantly different in any other CC subregions.
  
  
  CONCLUSIONS
  As patients with MDD were already experiencing acute episodes, future studies of individuals at risk for MDD are warranted to elucidate the interhemispheric connectivity abnormalities associated with the predisposition to MDD.
  
  
  CONCLUSIONS
  The findings demonstrate abnormalities in the structural integrity of the anterior genu of the CC in medication-naive individuals with MDD, which may contribute to impairment of interhemispheric connectivity in patients with this disorder.
authors.affiliation: Department of Radiology, The First Affiliated Hospital, China Medical University, Shenyang, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Xu
authors.forename: Wenyan
authors.initials: W
authors.lastname: Jiang
authors.forename: Ling
authors.initials: L
authors.lastname: Ren
authors.forename: Xuan
authors.initials: X
authors.lastname: Ouyang
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Jiang
authors.forename: Feng
authors.initials: F
authors.lastname: Wu
authors.forename: Lingtao
authors.initials: L
authors.lastname: Kong
authors.forename: Fay
authors.initials: F
authors.lastname: Womer
authors.forename: Zhening
authors.initials: Z
authors.lastname: Liu
authors.forename: Hilary P
authors.initials: HP
authors.lastname: Blumberg
authors.forename: Yanqing
authors.initials: Y
authors.lastname: Tang
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
mesh_terms: D000328:Adult; D016880:Anisotropy; D001921:Brain / Q000503:physiopathology; D016022:Case-Control Studies; D003337:Corpus Callosum / Q000503:physiopathology*; D003865:Major Depressive Disorder / Q000503:physiopathology*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult