title: A pilot study of visual backward masking performance among affected versus unaffected offspring of parents with bipolar disorder.
abstract: BACKGROUND
  Cognitive dysfunction is evident in some euthymic patients with established bipolar disorder (BD), including deficits in visual backward masking (VBM) tasks which map to a specific neural pathway. A high-risk paradigm would clarify the temporal relation of cognitive dysfunction to clinical course.
  
  
  METHODS
  We compared euthymic offspring (age range: 18-32 years) of lithium-responsive bipolar parents with and without a previous lifetime history of psychiatric illness to healthy comparison subjects with a negative family history, on a VBM task that requires target location.
  
  
  RESULTS
  High-risk offspring with no lifetime psychiatric history performed the VBM task at levels of healthy controls. High-risk offspring with a previous history of a mood disorder, in complete remission, made significantly more errors at short target-mask intervals than control or never ill offspring. These higher error rates were not a consequence of faster response times.
  
  
  CONCLUSIONS
  There is preliminary evidence of specific cognitive dysfunction early in the course of illness in affected offspring of parents with lithium responsive BD. VBM is ideal for future longitudinal studies addressing whether cognitive dysfunction in BD is a trait marker or a consequence of illness manifestation.
authors.affiliation: McMaster University, Hamilton, Ontario, Canada. macqueng@univmail.cis.msmaster.ca
authors.forename: Glenda M
authors.initials: GM
authors.lastname: MacQueen
authors.forename: Paul
authors.initials: P
authors.lastname: Grof
authors.forename: Martin
authors.initials: M
authors.lastname: Alda
authors.forename: Michael
authors.initials: M
authors.lastname: Marriott
authors.forename: L Trevor
authors.initials: LT
authors.lastname: Young
authors.forename: Anne
authors.initials: A
authors.lastname: Duffy
mesh_terms: D000293:Adolescent; D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy / Q000453:epidemiology* / Q000523:psychology*; D016241:Child of Impaired Parents / Q000523:psychology* / Q000706:statistics & numerical data*; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D016651:Lithium Carbonate / Q000627:therapeutic use; D008297:Male; D019964:Mood Disorders / Q000453:epidemiology; D009483:Neuropsychological Tests; D010290:Parents / Q000523:psychology*; D010468:Perceptual Disorders / Q000453:epidemiology*; D010470:Perceptual Masking / Q000502:physiology*; D010865:Pilot Projects; D011930:Reaction Time; D012720:Severity of Illness Index; D014796:Visual Perception / Q000502:physiology*
chemical_list: D014150:Antipsychotic Agents; D016651:Lithium Carbonate