title: Resting-state functional connectivity of emotion regulation networks in euthymic and non-euthymic bipolar disorder patients.
abstract: BACKGROUND
  Previous functional magnetic resonance imaging studies in bipolar disorder (BD) have evidenced changes in functional connectivity (FC) in brain areas associated with emotion processing, but how these changes vary with mood state and specific clinical symptoms is not fully understood.
  
  
  METHODS
  We investigated resting-state FC between a priori regions of interest (ROIs) from the default-mode network and key structures for emotion processing and regulation in 27 BD patients and 27 matched healthy controls. We further compared connectivity patterns in subgroups of 15 euthymic and 12 non-euthymic patients and tested for correlations of the connectivity strength with measures of mood, anxiety, and rumination tendency. No correction for multiple comparisons was applied given the small population sample and pre-defined target ROIs.
  
  
  RESULTS
  Overall, regardless of mood state, BD patients exhibited increased FC of the left amygdala with left sgACC and PCC, relative to controls. In addition, non-euthymic BD patients showed distinctive decrease in FC between right amygdala and sgACC, whereas euthymic patients showed lower FC between PCC and sgACC. Euthymic patients also displayed increased FC between sgACC and right VLPFC. The sgACC-PCC and sgACC-left amygdala connections were modulated by rumination tendency in non-euthymic patients, whereas the sgACC-VLPFC connection was modulated by both the current mood and tendency to ruminate.
  
  
  CONCLUSIONS
  Our results suggest that sgACC-amygdala coupling is critically affected during mood episodes, and that FC of sgACC play a pivotal role in mood normalization through its interactions with the VLPFC and PCC. However, these preliminary findings require replication with larger samples of patients.
authors.affiliation: Laboratory for Behavioral Neurology and Imaging of Cognition, Department of Neuroscience, University of Geneva, Geneva, Switzerland. Electronic address: gwladys.rey@unige.ch.
authors.forename: G
authors.initials: G
authors.lastname: Rey
authors.affiliation: Laboratory for Behavioral Neurology and Imaging of Cognition, Department of Neuroscience, University of Geneva, Geneva, Switzerland; Department of Mental Health and Psychiatry, Division of Psychiatric Specialties, Mood Disorder Program, Geneva University Hospitals, Geneva, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Piguet
authors.affiliation: Department of Psychology, University of Bonn, Bonn, Germany; Institute of Neuroscience and Medicine [INM-1], Research Center Jülich, Jülich, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Benders
authors.affiliation: Department of Mental Health and Psychiatry, Division of Psychiatric Specialties, Mood Disorder Program, Geneva University Hospitals, Geneva, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Favre
authors.affiliation: Institute of Neuroscience and Medicine [INM-1], Research Center Jülich, Jülich, Germany; Institute for Clinical Neuroscience and Medical Psychology, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany.
authors.forename: S B
authors.initials: SB
authors.lastname: Eickhoff
authors.affiliation: Department of Mental Health and Psychiatry, Division of Psychiatric Specialties, Mood Disorder Program, Geneva University Hospitals, Geneva, Switzerland.
authors.forename: J-M
authors.initials: JM
authors.lastname: Aubry
authors.affiliation: Laboratory for Behavioral Neurology and Imaging of Cognition, Department of Neuroscience, University of Geneva, Geneva, Switzerland; Department of Neurology, Geneva University Hospitals, Geneva, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Vuilleumier
mesh_terms: D000328:Adult; D000679:Amygdala / Q000503:physiopathology; D001714:Bipolar Disorder / Q000503:physiopathology* / Q000523:psychology; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods; D016022:Case-Control Studies; D003527:Cyclothymic Disorder / Q000503:physiopathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000503:physiopathology*; D009778:Occipital Lobe / Q000503:physiopathology
keywords: Bipolar disorder; Depression; FMRI; Functional connectivity; Mood; Rumination