title: Mood-congruent amygdala responses to subliminally presented facial expressions in major depression: associations with anhedonia.
abstract: BACKGROUND
  Anhedonia has long been recognized as a key feature of major depressive disorders, but little is known about the association between hedonic symptoms and neurobiological processes in depressed patients. We investigated whether amygdala mood-congruent responses to emotional stimuli in depressed patients are correlated with anhedonic symptoms at automatic levels of processing.
  
  
  METHODS
  We measured amygdala responsiveness to subliminally presented sad and happy facial expressions in depressed patients and matched healthy controls using functional magnetic resonance imaging. Amygdala responsiveness was compared between patients and healthy controls within a 2 (group) x 2 (emotion) design. In addition, we correlated patients' amygdala responsiveness to sad and happy facial stimuli with self-report questionnaire measures of anhedonia.
  
  
  RESULTS
  We included 35 patients and 35 controls in our study. As in previous studies, we observed a strong emotion x group interaction in the bilateral amygdala: depressed patients showed greater amygdala responses to sad than happy faces, whereas healthy controls responded more strongly to happy than sad faces. The lack of automatic right amygdala responsiveness to happy faces in depressed patients was associated with higher physical anhedonia scores.
  
  
  CONCLUSIONS
  Almost all depressed patients were taking antidepressant medications.
  
  
  CONCLUSIONS
  We replicated our previous finding of depressed patients showing automatic amygdala mood-congruent biases in terms of enhanced reactivity to negative emotional stimuli and reduced activity to positive emotional stimuli. The altered amygdala processing of positive stimuli in patients was associated with anhedonia scores. The results indicate that reduced amygdala responsiveness to positive stimuli may contribute to anhedonic symptoms due to reduced/inappropriate salience attribution to positive information at very early processing levels.
authors.affiliation: Department of Psychiatry, University of Münster, Münster, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Stuhrmann
authors.forename: Katharina
authors.initials: K
authors.lastname: Dohm
authors.forename: Harald
authors.initials: H
authors.lastname: Kugel
authors.forename: Peter
authors.initials: P
authors.lastname: Zwanzger
authors.forename: Ronny
authors.initials: R
authors.lastname: Redlich
authors.forename: Dominik
authors.initials: D
authors.lastname: Grotegerd
authors.forename: Astrid Veronika
authors.initials: AV
authors.lastname: Rauch
authors.forename: Volker
authors.initials: V
authors.lastname: Arolt
authors.forename: Walter
authors.initials: W
authors.lastname: Heindel
authors.forename: Thomas
authors.initials: T
authors.lastname: Suslow
authors.forename: Pienie
authors.initials: P
authors.lastname: Zwitserlood
authors.forename: Udo
authors.initials: U
authors.lastname: Dannlowski
mesh_terms: D000328:Adult; D000339:Affect / Q000502:physiology*; D000679:Amygdala / Q000503:physiopathology*; D059445:Anhedonia / Q000502:physiology*; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000503:physiopathology*; D005149:Facial Expression; D005260:Female; D007839:Functional Laterality; D059907:Functional Neuroimaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D013360:Subliminal Stimulation