title: Disrupted Brain Activation and Deactivation Pattern during Semantic Verbal Fluency Task in Patients with Major Depression.
abstract: BACKGROUND
  Patients with major depressive disorder (MDD) exhibit cognitive impairment, and evidence suggests that the semantic version of the verbal fluency task is a reliable cognitive marker of the disorder. Here, using functional magnetic resonance imaging (fMRI), we investigated the dysfunction of neural processing in acute depression and examined the effects of a 6-week pharmacological intervention.
  
  
  METHODS
  Sixteen patients with MDD participated in 2 fMRI sessions, and 16 healthy control (HC) subjects participated in 1 fMRI session. During each fMRI session, the participants performed a semantic verbal fluency task. Brain activity during the task was compared between groups (MDD 1st fMRI vs. HC) and times (MDD 1st fMRI vs. 2nd fMRI).
  
  
  RESULTS
  Significant brain hypoactivation was observed in MDD patients at the prefrontal, lateral parietal, and limbic regions compared to HC, and MDD patients exhibited hyperactivation at the left precuneus compared to HC. Hypoactivity of the left dorsolateral prefrontal cortex (DLPFC) and hyperactivity of the precuneus were normalized with treatment.
  
  
  CONCLUSIONS
  Hypoactivation of the left DLPFC and hyperactivation of the precuneus should be considered as dysregulation of anticorrelated brain networks during a cognitive demanding task. This failure of network regulation may be an important factor in the pathophysiology of MDD.
authors.affiliation: Department of Psychiatry and Neurosciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Takamura
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Okamoto
authors.forename: Go
authors.initials: G
authors.lastname: Okada
authors.forename: Shigeru
authors.initials: S
authors.lastname: Toki
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Osamu
authors.initials: O
authors.lastname: Yamamoto
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Jitsuiki
authors.forename: Norio
authors.initials: N
authors.lastname: Yokota
authors.forename: Tatsuji
authors.initials: T
authors.lastname: Tamura
authors.forename: Akiko
authors.initials: A
authors.lastname: Kurata
authors.forename: Yoko
authors.initials: Y
authors.lastname: Kaichi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Akiyama
authors.forename: Kazuo
authors.initials: K
authors.lastname: Awai
authors.forename: Shigeto
authors.initials: S
authors.lastname: Yamawaki
mesh_terms: D000328:Adult; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D012660:Semantics; D055815:Young Adult