title: Self-reported impulsivity in Huntington's disease patients and relationship to executive dysfunction and reward responsiveness.
abstract: BACKGROUND
  Few studies have directly investigated impulsivity in Huntington's disease (HD) despite known changes in dopaminergic and frontal functioning, changes that have been associated with impulsivity in other disorders and in the normal population. This study sought to further categorize impulsivity in HD through examining differences in self-reported impulsivity between community controls and HD patients, the relationship between executive dysfunction and impulsivity, and the relationship of a reward/punishment behavioral inhibition task in relation to these self-report measures. It was expected that HD patients would report higher impulsivity and executive dysfunction and that these measures would relate to a reward/punishment behavioral inhibition task.
  
  
  METHODS
  The Barratt Impulsivity Scale (BIS-11) and Behavioral Inhibition/Behavioral Activation Scale (BIS/BAS) were completed, and the Mini-Mental State Examination (MMSE) and a reward-based flanker task with punishing and rewarding conditions were administered to 22 HD patients and 14 control participants.
  
  
  RESULTS
  HD patients reported higher trait impulsivity (BIS-11) and executive dysfunction (Frontal Systems Behavior Scale, FrSBE) but not increased impulsivity on the BIS/BAS relative to controls. Higher BIS-11 scores were related to increased self-reported executive dysfunction and the attention/working memory factor of the MMSE. On a reward/punishment behavioral inhibition task, BAS was uniquely related to increased accuracy on rewarding trials of the flanker task, but was not related to punishing trials in HD patients.
  
  
  CONCLUSIONS
  The relationships found suggest that trait impulsivity is reported higher in HD and may not be driven by altered reward evaluation and the appetitive nature of stimuli but rather by increased executive dysfunction and lack of sensitivity to punishment. Impulsivity in HD may represent a combination of trait impulsivity, altered dopaminergic circuitry, and executive dysfunction. Understanding impulsivity in HD is important as it is related to increased risk to the patient and difficult behaviors for the caregiver, and sheds light on the disease process.
authors.affiliation: a Department of Psychology , University of South Florida , Tampa , FL , USA.
authors.forename: Patricia L
authors.initials: PL
authors.lastname: Johnson
authors.affiliation: a Department of Psychology , University of South Florida , Tampa , FL , USA.
authors.forename: Geoffrey F
authors.initials: GF
authors.lastname: Potts
authors.affiliation: b Department of Neurology , University of South Florida , Tampa , FL , USA.
authors.forename: Juan
authors.initials: J
authors.lastname: Sanchez-Ramos
authors.affiliation: a Department of Psychology , University of South Florida , Tampa , FL , USA.|b Department of Neurology , University of South Florida , Tampa , FL , USA.
authors.forename: Cynthia R
authors.initials: CR
authors.lastname: Cimino
mesh_terms: D000328:Adult; D060825:Cognitive Dysfunction / Q000209:etiology / Q000503:physiopathology*; D056344:Executive Function / Q000502:physiology*; D005260:Female; D006801:Humans; D006816:Huntington Disease / Q000150:complications / Q000503:physiopathology*; D007175:Impulsive Behavior / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011678:Punishment; D012201:Reward; D057566:Self Report
keywords: Executive dysfunction; Huntington’s disease; Impulsivity; Punishment; Reward.