title: Possible involvement of rumination in gray matter abnormalities in persistent symptoms of major depression: an exploratory magnetic resonance imaging voxel-based morphometry study.
abstract: BACKGROUND
  A recent meta-analysis of many magnetic resonance imaging (MRI) studies has identified brain regions with gray matter (GM) abnormalities in patients with major depressive disorder (MDD). A few studies addressing GM abnormalities in patients with treatment-resistant depression (TRD) have yielded inconsistent results. Moreover, although TRD patients tend to exhibit ruminative thoughts, it remains unclear whether rumination is related to GM abnormalities in such patients or not.
  
  
  METHODS
  We conducted structural MRI scans and voxel-based morphometry (VBM) to identify GM differences among 29 TRD patients and 29 healthy age-matched and sex-matched controls. A response style questionnaire was used to assess the respective degrees of rumination in TRD patients. Structural correlates of rumination were examined.
  
  
  RESULTS
  TRD patients showed several regions with smaller GM volume than in healthy subjects: the left dorsal anterior cingulate cortex (ACC), right ventral ACC, right superior frontal gyrus, right cerebellum (Crus I), and cerebellar vermis. GM volumes in these regions did not correlate to rumination. However, whole-brain analysis revealed that rumination was positively correlated with the GM volume in the right superior temporal gyrus in TRD patients.
  
  
  CONCLUSIONS
  Structural correlates of rumination were examined only in TRD patients.
  
  
  CONCLUSIONS
  Our data provide additional evidence supporting the hypothesis that TRD patients show GM abnormalities compared with healthy subjects. Furthermore, this report is the first to describe a study identifying brain regions for which the GM volume is correlated with rumination in TRD patients. These results improve our understanding of the anatomical characteristics of TRD.
authors: Department of Psychiatry and Neurosciences, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan.
authors: Akihiko
authors: A
authors: Machino
authors: Graduate School of the Humanities, Sensyu University, 2-1-1 Higashi Mita, Tama-ku, Kanagawa, Kawasaki 214-8580, Japan.
authors: Yoshihiko
authors: Y
authors: Kunisato
authors: Department of Psychiatry and Neurosciences, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation (JST), 4-1-8 Honmachi, Kawaguchi, Saitama 332-0012, Japan.
authors: Tomoya
authors: T
authors: Matsumoto
authors: Department of Psychiatry and Neurosciences, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan; Faculty of Psychology, Otemon Gakuin University, 2-1-15 Nishiai, Ibaraki, Osaka 567-8502, Japan.
authors: Shinpei
authors: S
authors: Yoshimura
authors: Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan.
authors: Kazutaka
authors: K
authors: Ueda
authors: Laboratory of Molecular and Cellular Pharmacology, Faculty of Pharmatheutical Sciences, Hiroshima International University, 5-1-1 Hirokoshingai, Kure, Hiroshima 737-0112, Japan.
authors: Yosuke
authors: Y
authors: Yamawaki
authors: Department of Psychiatry and Neurosciences, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation (JST), 4-1-8 Honmachi, Kawaguchi, Saitama 332-0012, Japan.
authors: Go
authors: G
authors: Okada
authors: Department of Psychiatry and Neurosciences, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation (JST), 4-1-8 Honmachi, Kawaguchi, Saitama 332-0012, Japan.
authors: Yasumasa
authors: Y
authors: Okamoto
authors: Department of Psychiatry and Neurosciences, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation (JST), 4-1-8 Honmachi, Kawaguchi, Saitama 332-0012, Japan. Electronic address: yamawaki@hiroshima-u.ac.jp.
authors: Shigeto
authors: S
authors: Yamawaki
mesh_terms: D000328:Adult; D001921:Brain / Q000002:abnormalities; D002531:Cerebellum / Q000002:abnormalities; D003865:Major Depressive Disorder / Q000473:pathology* / Q000523:psychology*; D061218:Depressive Disorder, Treatment-Resistant; D005260:Female; D066128:Gray Matter / Q000002:abnormalities*; D006179:Gyrus Cinguli / Q000002:abnormalities; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D013850:Thinking
keywords: Gray matter volume; Magnetic resonance imaging; Rumination; Treatment-resistant depression; Voxel-based morphometry