title: Tract-based analysis of white matter integrity in psychotic and nonpsychotic bipolar disorder.
abstract: At least 50% of individuals with bipolar disorder (BD) present with psychosis during their lifetime. Psychotic symptoms have sometimes been linked to specific genetic and phenotypic markers. This study aims to explore potential differences between bipolar disorder subtypes by measuring white matter integrity of the brain and relationships with clinical measures.
  
  
  
  Diffusion tensor imaging and clinical measures were acquired from 102 participants, grouped as psychotic bipolar disorder (PBD) (n=48), non-psychotic bipolar disorder (NBD) (n=24), and healthy controls (n=30). We utilized a powerful, automated tool (TRACULA: Tracts Constrained by Underlying Anatomy) to analyze the fractional anisotropy (FA) and mean diffusivity (MD) of 18 white matter tracts.
  
  
  
  Decreased FA in numerous tracts was observed in bipolar disorder groups compared to healthy controls: bilateral cingulum-cingulate gyrus bundles, corticospinal tracts, and superior longitudinal fasciculi as well as the right hemisphere cingulum-angular bundle. Only left uncinate fasciculus FA differed between PBD and NPBD groups. We found no group differences in MD. Positive symptoms correlated with FA in the superior (inversely) and inferior (directly) longitudinal fasciculi. Negative symptoms directly correlated with mean FA of the corticospinal tract and cingulum-angular bundle.
  
  
  
  Neurotropic, mood-stabilizing medication prescribed for individuals with BD may interact with measures of white matter integrity in our BD participants.
  
  
  
  Our results indicate decreased white matter coherence in BD. Minimal differences in white matter FA between PBD and NPBD participants suggest related underlying neurobiology.
authors.affiliation: Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States.
authors.forename: Andrew
authors.initials: A
authors.lastname: Ji
authors.affiliation: Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States.
authors.forename: Douglass
authors.initials: D
authors.lastname: Godwin
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, United States.
authors.forename: Jerrel
authors.initials: J
authors.lastname: Rutlin
authors.affiliation: Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States.
authors.forename: Sridhar
authors.initials: S
authors.lastname: Kandala
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, United States.
authors.forename: Joshua S
authors.initials: JS
authors.lastname: Shimony
authors.affiliation: Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States. Electronic address: mamahd@psychiatry.wustl.edu.
authors.forename: Daniel
authors.initials: D
authors.lastname: Mamah
mesh_terms: D000328:Adult; D015415:Biomarkers; D001714:Bipolar Disorder / Q000473:pathology*; D001921:Brain / Q000473:pathology; D016022:Case-Control Studies; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D006179:Gyrus Cinguli / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology; D011618:Psychotic Disorders / Q000000981:diagnostic imaging / Q000473:pathology*; D011712:Pyramidal Tracts; D013702:Temporal Lobe / Q000473:pathology; D066127:White Matter / Q000000981:diagnostic imaging / Q000473:pathology*
chemical_list: D015415:Biomarkers
keywords: Bipolar disorder; DTI; Psychosis; TRACULA; White matter