title: Bipolar I disorder and major depressive disorder show similar brain activation during depression.
abstract: OBJECTIVE
  Despite different treatments and courses of illness, depressive symptoms appear similar in major depressive disorder (MDD) and bipolar I disorder (BP-I). This similarity of depressive symptoms suggests significant overlap in brain pathways underlying neurovegetative, mood, and cognitive symptoms of depression. These shared brain regions might be expected to exhibit similar activation in individuals with MDD and BP-I during functional magnetic resonance imaging (fMRI).
  
  
  METHODS
  fMRI was used to compare regional brain activation in participants with BP-I (n = 25) and MDD (n = 25) during a depressive episode as well as 25 healthy comparison (HC) participants. During the scans, participants performed an attentional task that incorporated emotional pictures.
  
  
  RESULTS
  During the viewing of emotional images, subjects with BP-I showed decreased activation in the middle occipital gyrus, lingual gyrus, and middle temporal gyrus compared to both subjects with MDD and HC participants. During attentional processing, participants with MDD had increased activation in the parahippocampus, parietal lobe, and postcentral gyrus. However, among these regions, only the postcentral gyrus also showed differences between MDD and HC participants.
  
  
  CONCLUSIONS
  No differences in cortico-limbic regions were found between participants with BP-I and MDD during depression. Instead, the major differences occurred in primary and secondary visual processing regions, with decreased activation in these regions in BP-I compared to major depression. These differences were driven by abnormal decreases in activation seen in the participants with BP-I. Posterior activation changes are a common finding in studies across mood states in participants with BP-I.
authors.affiliation: Department of Psychiatry, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Cerullo
authors.forename: James C
authors.initials: JC
authors.lastname: Eliassen
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Smith
authors.forename: David E
authors.initials: DE
authors.lastname: Fleck
authors.forename: Erik B
authors.initials: EB
authors.lastname: Nelson
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Strawn
authors.forename: Martine
authors.initials: M
authors.lastname: Lamy
authors.forename: Melissa P
authors.initials: MP
authors.lastname: DelBello
authors.forename: Caleb M
authors.initials: CM
authors.lastname: Adler
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Strakowski
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology; D001714:Bipolar Disorder / Q000150:complications*; D001921:Brain / Q000098:blood supply / Q000503:physiopathology*; D001931:Brain Mapping; D003071:Cognition / Q000502:physiology; D003863:Depression / Q000209:etiology* / Q000473:pathology*; D003865:Major Depressive Disorder / Q000150:complications*; D004644:Emotions / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: bipolar disorder; emotion; functional magnetic resonance imaging (fMRI); major depressive disorder; neurophysiology