title: State-Dependent Differences in Emotion Regulation Between Unmedicated Bipolar Disorder and Major Depressive Disorder.
abstract: OBJECTIVE
  Major depressive disorder (MDD) and bipolar disorder (BD) are difficult to distinguish clinically during the depressed or remitted states. Both mood disorders are characterized by emotion regulation disturbances; however, little is known about emotion regulation differences between MDD and BD. Better insight into these differences would be helpful for differentiation based on disorder-specific underlying pathophysiological mechanisms. Previous studies comparing these disorders often allowed medication use, limiting generalizability and validity. Moreover, patients with MDD and BD were mostly compared during the depressed, but not the remitted, state, while state might potentially modulate differences between MDD and BD.
  
  
  OBJECTIVE
  To investigate positive and negative emotion regulation in medication-free patients with MDD and BD in 2 mood states: depressed or remitted.
  
  
  METHODS
  A cross-sectional study conducted from May 2009 to August 2013 comparing behavioral and functional magnetic resonance imaging emotion regulation data of 42 patients with MDD, 35 with BD, and 36 healthy control (HC) participants free of psychotropic medication recruited from several psychiatric institutions across the Netherlands.
  
  
  METHODS
  A voluntary emotion regulation functional magnetic resonance imaging task using positive and negative pictures.
  
  
  METHODS
  Behavioral and functional magnetic resonance imaging blood oxygen level-dependent responses during emotion regulation.
  
  
  RESULTS
  In the remitted state, only patients with BD showed impaired emotion regulation (t = 3.39; P < .001; Cohen d = 0.70), irrespective of emotion type and associated with increased dorsolateral prefrontal cortex activity compared with those with MDD and healthy control participants (P = .008). In the depressed state, patients with MDD and BD differed with regard to happy vs sad emotion regulation (t = 4.19; P < .001; Cohen d = 1.66) associated with differences in rostral anterior cingulate activity (P < .001). Patients with MDD regulated sad and happy emotions poorly compared with those with BD and healthy control participants, while they demonstrated no rostral anterior cingulate difference between happy and sad emotion regulation. In contrast, patients with BD performed worse than those with MDD on sad emotion regulation but normal on happy emotion regulation, and they demonstrated significantly less rostral anterior cingulate activity while regulating happy compared with sad emotions.
  
  
  CONCLUSIONS
  Medication-free patients with MDD vs BD appear to differ in brain activations during emotion regulation, both while depressed and in remission. These different neuropathophysiological mechanisms between MDD and BD may be useful for further development of additional diagnostic tools.
authors.affiliation: Program for Mood Disorders, Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Maria M
authors.initials: MM
authors.lastname: Rive
authors.affiliation: Program for Mood Disorders, Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Roel J T
authors.initials: RJ
authors.lastname: Mocking
authors.affiliation: Program for Mood Disorders, Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Maarten W J
authors.initials: MW
authors.lastname: Koeter
authors.affiliation: Program for Mood Disorders, Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Guido
authors.initials: G
authors.lastname: van Wingen
authors.affiliation: Department of Psychiatry, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Stella J
authors.initials: SJ
authors.lastname: de Wit
authors.affiliation: Department of Psychiatry, VU University Medical Center, Amsterdam, the Netherlands3Department of Anatomy and Neurosciences, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Odile A
authors.initials: OA
authors.lastname: van den Heuvel
authors.affiliation: Department of Psychiatry, VU University Medical Center, Amsterdam, the Netherlands3Department of Anatomy and Neurosciences, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Dick J
authors.initials: DJ
authors.lastname: Veltman
authors.affiliation: Program for Mood Disorders, Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands4Department of Psychiatry, Mood, and Anxiety Disorders, University Medical Center Groningen, University of Groningen, Groning.
authors.forename: Henricus G
authors.initials: HG
authors.lastname: Ruhé
authors.affiliation: Program for Mood Disorders, Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands5Department of Psychiatry, Radboud University Medical Center, Nijmegen, the Netherlands6Donders Institute for Brain, Cognitio.
authors.forename: Aart H
authors.initials: AH
authors.lastname: Schene
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000503:physiopathology* / Q000523:psychology; D001921:Brain / Q000503:physiopathology; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D003865:Major Depressive Disorder / Q000503:physiopathology* / Q000523:psychology; D004644:Emotions; D005260:Female; D059907:Functional Neuroimaging; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D017397:Prefrontal Cortex / Q000503:physiopathology*