title: Dysfunctional decision-making related to white matter alterations in bipolar I disorder.
abstract: OBJECTIVE
  This study investigated how frontal white matter (WM) alterations in patients with bipolar I disorder (BD-I) are linked to motivational dysregulation, often reported in the form of risk-taking and impulsivity, and whether structure-function relations in patients might differ from healthy subjects (HC).
  
  
  METHODS
  We acquired diffusion data from 24 euthymic BD-I patients and 24 controls, to evaluate WM integrity of selected frontal tracts. Risk-taking was assessed by the Cambridge Gambling Task and impulsivity by self-report with the Barratt-Impulsiveness Scale.
  
  
  RESULTS
  BD-I patients displayed significantly lower integrity in the right cingulum compared to HC. They also showed more risk-taking behavior and reported increased trait-impulsivity. Risk-taking was negatively associated with WM integrity in the right cingulum. Impulsivity was not related to WM integrity in investigated tracts. Together with age and sex, FA in the cingulum explained 25% of variance in risk-taking scores in all study participants. The left inferior fronto-occipital fasciculus (IFOF) was specifically predictive of risk-taking behavior in BD-I patients, but not in HC.
  
  
  CONCLUSIONS
  The employed parameters did not allow us to specify the exact origin of WM changes, nor did the method allow the analysis of specific brain subregions. Also, sample size was moderate and the sample included patients with lifetime alcohol dependence/abuse, hence effects found need replication and have to be interpreted with caution.
  
  
  CONCLUSIONS
  Our results further strengthen recent models linking structural changes in frontal networks to behavioral markers of BD-I. They extend recent findings by showing that risk-taking is also linked to the cingulum in BD-I and HC, while other prefrontal tracts (IFOF) are specifically implicated in risk-taking behavior in BD-I patients. Meanwhile, self-reported impulsivity was not associated with WM integrity of the tracts investigated in our study.
authors.affiliation: Department of Clinical Psychology and Neuropsychology, Institute for Psychology, Johannes Gutenberg-University of Mainz, Mainz, Germany.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Scholz
authors.affiliation: UNIACT, Psychiatry Team, NeuroSpin, I2BM, CEA Saclay, Gif-Sur-Yvette, France; Inserm U955, Equipe 15 "Psychiatrie translationnelle", APHP, CHU Mondor, DHU PePsy, Université Paris Est, Fondamental Foundation, Créteil, France.
authors.forename: Josselin
authors.initials: J
authors.lastname: Houenou
authors.affiliation: Department of Clinical Psychology and Neuropsychology, Institute for Psychology, Johannes Gutenberg-University of Mainz, Mainz, Germany.
authors.forename: Bianca
authors.initials: B
authors.lastname: Kollmann
authors.affiliation: Neurospin, UNIRS Lab, CEA Saclay, Gif Sur Yvette, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Duclap
authors.affiliation: Neurospin, UNIRS Lab, CEA Saclay, Gif Sur Yvette, France.
authors.forename: Cyril
authors.initials: C
authors.lastname: Poupon
authors.affiliation: Department of Clinical Psychology and Neuropsychology, Institute for Psychology, Johannes Gutenberg-University of Mainz, Mainz, Germany; Section for Experimental Psychopathology and Neuroimaging, Department of General Psychiatry, Center for Psychosocial Medicine, University of Heidelberg, Heidelberg, Germany. Electronic address: wessa@uni-mainz.de.
authors.forename: Michèle
authors.initials: M
authors.lastname: Wessa
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000473:pathology* / Q000503:physiopathology*; D016022:Case-Control Studies; D003657:Decision Making / Q000502:physiology*; D005260:Female; D006801:Humans; D007175:Impulsive Behavior; D008297:Male; D008875:Middle Aged; D009415:Nerve Net; D012309:Risk-Taking; D057566:Self Report; D066127:White Matter / Q000473:pathology*
keywords: Bipolar-I disorder; DTI; Impulsivity; Risk-taking; White matter