title: Cognitive flexibility in phenotypes of pediatric bipolar disorder.
abstract: OBJECTIVE
  Clinicians and researchers debate whether children with chronic, nonepisodic irritability should receive the diagnosis of bipolar disorder (BD). To address this debate, we evaluated cognitive flexibility, or the ability to adapt to changing contingencies, in three groups of children: narrow-phenotype BD (NP-BD; full-duration manic episodes of elevated/expansive mood; N = 50; 13.1 +/- 2.9 years), severe mood dysregulation (SMD; chronic, nonepisodic irritability; N = 44; 12.2 +/- 2.1 years), and healthy controls (N = 43; 13.6 +/- 2.4 years). Cognitive flexibility is relevant to symptoms of BD involving dysfunctional reward systems (e.g., excessive goal-directed activity and pleasure-seeking in mania; anhedonia in depression).
  
  
  METHODS
  We studied simple and compound reversal stages of the intra-/extradimensional shift task and change task that involves inhibiting a prepotent response and substituting a novel response.
  
  
  RESULTS
  On the simple reversal, NP-BD youths were significantly more impaired than both the SMD group and controls. On the compound reversal, NP-BD and SMD youths performed worse than controls. On the change task, NP-BD youths were slower to adapt than SMD subjects.
  
  
  CONCLUSIONS
  Phenotypic differences in cognitive flexibility may reflect different brain/behavior mechanisms in these two patient populations.
authors.affiliation: All authors were affiliated with the National Institute of Mental Health (NIMH) Division of Intramural Research Program when this work was prepared; Dr. McClure is currently with the Department of Psychology, Georgia State University. Electronic address: Dicksted@mail.nih.gov.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Dickstein
authors.affiliation: All authors were affiliated with the National Institute of Mental Health (NIMH) Division of Intramural Research Program when this work was prepared; Dr. McClure is currently with the Department of Psychology, Georgia State University.
authors.forename: Eric E
authors.initials: EE
authors.lastname: Nelson
authors.affiliation: All authors were affiliated with the National Institute of Mental Health (NIMH) Division of Intramural Research Program when this work was prepared; Dr. McClure is currently with the Department of Psychology, Georgia State University.
authors.forename: Erin B
authors.initials: EB
authors.lastname: McCLURE
authors.affiliation: All authors were affiliated with the National Institute of Mental Health (NIMH) Division of Intramural Research Program when this work was prepared; Dr. McClure is currently with the Department of Psychology, Georgia State University.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Grimley
authors.affiliation: All authors were affiliated with the National Institute of Mental Health (NIMH) Division of Intramural Research Program when this work was prepared; Dr. McClure is currently with the Department of Psychology, Georgia State University.
authors.forename: Lisa
authors.initials: L
authors.lastname: Knopf
authors.affiliation: All authors were affiliated with the National Institute of Mental Health (NIMH) Division of Intramural Research Program when this work was prepared; Dr. McClure is currently with the Department of Psychology, Georgia State University.
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Brotman
authors.affiliation: All authors were affiliated with the National Institute of Mental Health (NIMH) Division of Intramural Research Program when this work was prepared; Dr. McClure is currently with the Department of Psychology, Georgia State University.
authors.forename: Brendan A
authors.initials: BA
authors.lastname: Rich
authors.affiliation: All authors were affiliated with the National Institute of Mental Health (NIMH) Division of Intramural Research Program when this work was prepared; Dr. McClure is currently with the Department of Psychology, Georgia State University.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Pine
authors.affiliation: All authors were affiliated with the National Institute of Mental Health (NIMH) Division of Intramural Research Program when this work was prepared; Dr. McClure is currently with the Department of Psychology, Georgia State University.
authors.forename: Ellen
authors.initials: E
authors.lastname: Leibenluft
mesh_terms: D000293:Adolescent; D001714:Bipolar Disorder / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D002648:Child; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D015994:Incidence; D007508:Irritable Mood; D008297:Male; D009483:Neuropsychological Tests; D010507:Periodicity; D010641:Phenotype; D015995:Prevalence; D012720:Severity of Illness Index