title: Brain structural abnormalities in behavior therapy-resistant obsessive-compulsive disorder revealed by voxel-based morphometry.
abstract: BACKGROUND
  Although several functional imaging studies have demonstrated that behavior therapy (BT) modifies the neural circuits involved in the pathogenesis of obsessive-compulsive disorder (OCD), the structural abnormalities underlying BT-resistant OCD remain unknown.
  
  
  METHODS
  In this study, we examined the existence of regional structural abnormalities in both the gray matter and the white matter of patients with OCD at baseline using voxel-based morphometry in responders (n=24) and nonresponders (n=15) to subsequent BT. Three-dimensional T1-weighted magnetic resonance imaging was performed before the completion of 12 weeks of BT.
  
  
  RESULTS
  Relative to the responders, the nonresponders exhibited significantly smaller gray matter volumes in the right ventromedial prefrontal cortex, the right orbitofrontal cortex, the right precentral gyrus, and the left anterior cingulate cortex. In addition, relative to the responders, the nonresponders exhibited significantly smaller white matter volumes in the left cingulate bundle and the left superior frontal white matter.
  
  
  CONCLUSIONS
  These results suggest that the brain structures in several areas, including the orbitofrontal cortex, anterior cingulate cortex, and cingulate bundles, are related to the lack of a response to BT in patients with OCD. The use of a voxel-based morphometry approach may be advantageous to understanding differences in brain abnormalities between responders and nonresponders to BT.
authors.affiliation: Department of Psychiatry and Cognitive-Behavioral Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Hashimoto
authors.affiliation: Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Shutaro
authors.initials: S
authors.lastname: Nakaaki
authors.affiliation: Department of Psychiatry and Cognitive-Behavioral Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Kawaguchi
authors.affiliation: Department of Psychiatry and Cognitive-Behavioral Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Junko
authors.initials: J
authors.lastname: Sato
authors.affiliation: Department of Central Radiology, Nagoya City University Hospital, Nagoya, Japan.
authors.forename: Harumasa
authors.initials: H
authors.lastname: Kasai
authors.affiliation: Department of Psychiatry, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamae
authors.affiliation: Department of Psychiatry, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Jin
authors.initials: J
authors.lastname: Narumoto
authors.affiliation: Department of Psychiatry, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Miyata
authors.affiliation: Department of Health Promotion and Human Behavior, Kyoto University Graduate School of Medicine/School of Public Health, Kyoto, Japan ; Department of Clinical Epidemiology, Kyoto University Graduate School of Medicine/School of Public Health, Kyoto, Japan.
authors.forename: Toshi A
authors.initials: TA
authors.lastname: Furukawa
authors.affiliation: Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Mimura
keywords: OCD; orbitofrontal cortex; treatment resistance