title: Cortical inefficiency in patients with unipolar depression: an event-related FMRI study with the Stroop task.
abstract: BACKGROUND
  The present study is aimed to examine the neuronal correlates of Stroop interference in medication-free patients with major depressive disorder.
  
  
  METHODS
  Sixteen patients fulfilling Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria for unipolar depression and 16 healthy control subjects matched for age, gender, and education were included. All subjects underwent an event-related functional magnetic resonance imaging (fMRI) design with an adapted version of the Stroop task including congruent and incongruent task conditions. The fMRI experiment was conducted on a 1.5 T magnetic resonance (MR) scanner, and item responses were given manually by the subjects.
  
  
  RESULTS
  With regard to behavioral performance, patients revealed no differences in both reaction time and accuracy relative to control subjects. With regard to brain activations, direct comparison of patients with control subjects in the interference condition revealed hyperactivity in rostral anterior cingulate gyrus (rACG) and left dorsolateral prefrontal cortex (DLPFC) in depressive patients, which correlated strongly with the Stroop interference.
  
  
  CONCLUSIONS
  The study provides new evidence for the functioning and dissociation of the anterior cingulate in depressed patients. The greater prefrontal activation may reflect a cortical inefficiency due to hyperactivity in rACG enhancing the cognitive interferences from the emotional state.
authors.affiliation: Department of Psychiatry, University of Jena, Jena, Germany. wagner.gerd@uni-jena.de
authors.forename: Gerd
authors.initials: G
authors.lastname: Wagner
authors.forename: Esther
authors.initials: E
authors.lastname: Sinsel
authors.forename: Thomas
authors.initials: T
authors.lastname: Sobanski
authors.forename: Sabine
authors.initials: S
authors.lastname: Köhler
authors.forename: Varvara
authors.initials: V
authors.lastname: Marinou
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Mentzel
authors.forename: Heinrich
authors.initials: H
authors.lastname: Sauer
authors.forename: Ralf G M
authors.initials: RG
authors.lastname: Schlösser
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000503:physiopathology*; D003118:Color Perception / Q000502:physiology*; D003220:Conflict, Psychological; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000503:physiopathology*; D004292:Dominance, Cerebral / Q000502:physiology; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000502:physiology; D005260:Female; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007266:Inhibition, Psychological; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D017397:Prefrontal Cortex / Q000503:physiopathology*; D011932:Reading; D012016:Reference Values; D012660:Semantics; D013223:Statistics as Topic