title: White matter hyperintensities in affected and unaffected late teenage and early adulthood offspring of bipolar parents: a two-center high-risk study.
abstract: BACKGROUND
  White matter hyperintensities (WMHs) are among the most replicated neuroimaging findings in bipolar disorder (BD). It is not clear whether these lesions are an artifact of comorbid conditions, or whether they are directly associated with the disorder, or even represent biological risk factor for BD.
  
  
  METHODS
  To test whether WMHs meet criteria for an endophenotype of BD, we conducted a high-risk design study and recruited 35 affected, 44 unaffected relatives of bipolar probands (age range 15-30 years), matched by age and sex with 49 healthy controls without any personal or family history of psychiatric disorders. The presence of WMHs was determined from Fluid Attenuated Inversion Recovery (FLAIR) scans acquired on a 1.5 Tesla scanner using a validated semi-quantitative scale.
  
  
  RESULTS
  We found mostly low grade WMHs in all groups. The proportion of WMH-positive subjects was comparable between the unaffected high-risk, affected familial and control groups.
  
  
  CONCLUSIONS
  White matter hyperintensities did not meet criteria for an endophenotype of BD. Bipolar disorder in young subjects without comorbid conditions was not associated with increased rate of WMHs.
authors.affiliation: Department of Anatomy and Neurobiology, Dalhousie University, Halifax, Nova Scotia, Canada.
authors.forename: Eva
authors.initials: E
authors.lastname: Gunde
authors.forename: Tomas
authors.initials: T
authors.lastname: Novak
authors.forename: Miloslav
authors.initials: M
authors.lastname: Kopecek
authors.forename: Matthias
authors.initials: M
authors.lastname: Schmidt
authors.forename: Lukas
authors.initials: L
authors.lastname: Propper
authors.forename: Pavla
authors.initials: P
authors.lastname: Stopkova
authors.forename: Cyril
authors.initials: C
authors.lastname: Höschl
authors.forename: Anne
authors.initials: A
authors.lastname: Duffy
authors.forename: Martin
authors.initials: M
authors.lastname: Alda
authors.forename: Tomas
authors.initials: T
authors.lastname: Hajek
mesh_terms: D000293:Adolescent; D000328:Adult; D001714:Bipolar Disorder / Q000235:genetics / Q000523:psychology*; D001921:Brain / Q000473:pathology*; D016241:Child of Impaired Parents / Q000523:psychology* / Q000706:statistics & numerical data*; D005192:Family Health; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D055815:Young Adult