title: Sad mood induction has an opposite effect on amygdala response to emotional stimuli in euthymic patients with bipolar disorder and healthy controls.
abstract: BACKGROUND
  Aberrant amygdala reactivity to affective stimuli represents a candidate factor predisposing patients with bipolar disorder (BD) to relapse, but it is unclear to what extent amygdala reactivity is state-dependent. We evaluated the modulatory influence of mood on amygdala reactivity and functional connectivity in patients with remitted BD and healthy controls.
  
  
  METHODS
  Amygdala response to sad versus neutral faces was investigated using fMRI during periods of normal and sad mood induced by autobiographical scripts. We assessed the functional connectivity of the amygdala to characterize the influence of mood state on the network responsible for the amygdala response.
  
  
  RESULTS
  We included 20 patients with remitted BD and 20 controls in our study. The sad and normal mood exerted opposite effects on the amygdala response to emotional faces in patients compared with controls (F1,38 = 5.85, p = 0.020). Sad mood amplified the amygdala response to sad facial stimuli in controls but attenuated the amygdala response in patients. The groups differed in functional connectivity between the amygdala and the inferior prefrontal gyrus (p ≤ 0.05, family-wise error-corrected) of ventrolateral prefrontal cortex (vlPFC) corresponding to Brodmann area 47. The sad mood challenge increased connectivity during the period of processing sad faces in patients but decreased connectivity in controls.
  
  
  CONCLUSIONS
  Limitations to our study included long-term medication use in the patient group and the fact that we mapped only depressive (not manic) reactivity.
  
  
  CONCLUSIONS
  Our results support the role of the amygdala-vlPFC as the system of dysfunctional contextual affective processing in patients with BD. Opposite amygdala reactivity unmasked by the mood challenge paradigm could represent a trait marker of altered mood regulation in patients with BD.
authors.affiliation: The Prague Psychiatric Centre, the Third Faculty of Medicine, Charles University, Prague, Czech Republic and the Department of Psychiatry, Dalhousie University, Halifax, Canada.
authors.forename: Jiri
authors.initials: J
authors.lastname: Horacek
authors.affiliation: Prague Psychiatric Centre, Prague, Czech Republic.
authors.forename: Pavol
authors.initials: P
authors.lastname: Mikolas
authors.affiliation: Institute for Clinical and Experimental Medicine, Prague, Czech Republic.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Tintera
authors.affiliation: The Prague Psychiatric Centre, and the Third Faculty of Medicine, Charles University, Prague, Czech Republic.
authors.forename: Tomas
authors.initials: T
authors.lastname: Novak
authors.affiliation: The Prague Psychiatric Centre, and the Third Faculty of Medicine, Charles University, Prague, Czech Republic.
authors.forename: Tomas
authors.initials: T
authors.lastname: Palenicek
authors.affiliation: The Prague Psychiatric Centre, and the Third Faculty of Medicine, Charles University, Prague, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Brunovsky
authors.affiliation: The Prague Psychiatric Centre, and the Third Faculty of Medicine, Charles University, Prague, Czech Republic.
authors.forename: Cyril
authors.initials: C
authors.lastname: Höschl
authors.affiliation: Third Faculty of Medicine, Charles University, Prague, Czech Republic and the Department of Psychiatry, Dalhousie University, Halifax, Canada.
authors.forename: Martin
authors.initials: M
authors.lastname: Alda
mesh_terms: D000328:Adult; D000679:Amygdala / Q000503:physiopathology*; D001714:Bipolar Disorder / Q000503:physiopathology* / Q000523:psychology; D001931:Brain Mapping; D004644:Emotions / Q000502:physiology*; D005145:Face; D005149:Facial Expression; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000503:physiopathology; D010775:Photic Stimulation; D014796:Visual Perception / Q000502:physiology