title: Reward-seeking behavior in human narcolepsy.
abstract: OBJECTIVE
  The hypocretin system enhances signaling in the mesolimbic pathways regulating reward processing and addiction. Because individuals with narcolepsy with cataplexy have low hypocretin levels, we hypothesized that they may be less prone to risk- and reward-seeking behaviors, including substance abuse.
  
  
  METHODS
  Endpoints were performance on an array of psychometric tests (including the Eysenck Impulsiveness Scale, the Zuckerman Sensation Seeking Scale, the Gormally Binge Eating Scale, and the Beck Depression and Anxiety Inventory) and on the Balloon Analogue Risk Task (BART).
  
  
  METHODS
  Tertiary narcolepsy referral centers in Leiden (The Netherlands) and Boston (USA).
  
  
  METHODS
  Subjects with narcolepsy with cataplexy (n = 30), narcolepsy without cataplexy (n = 15), and controls (n = 32) matched for age, sex, and smoking behavior.
  
  
  METHODS
  None.
  
  
  RESULTS
  There was no difference in risk-taking behavior between narcolepsy with or without cataplexy and the control group, as measured using the BART and the array of questionnaires. However, subjects in the narcolepsy with cataplexy group had significantly higher scores on the Eysenck Impulsiveness Scale (p < 0.05), with 10.0% categorized as impulsive, compared to 6.7% of the narcolepsy without cataplexy group and none of the controls. Narcoleptics with cataplexy also scored significantly higher than controls on the Binge Eating Scale (p < 0.05), with moderate or severe binge eating in 23%. On the depression and anxiety scales, all narcolepsy patients, especially those with cataplexy, scored significantly higher than controls.
  
  
  CONCLUSIONS
  We found that narcoleptics with or without cataplexy generally have normal risk-taking behavior, but narcoleptics with cataplexy were more impulsive and more prone to binge eating than patients without cataplexy and controls. Our findings shed new light on the relation between sleepiness and impulsiveness. Furthermore, rates of depression and anxiety were higher in all narcoleptic subjects. However, using the current methods, no evidence could be found to support the hypothesis that hypocretin deficiency would affect reward-processing in humans.
authors.affiliation: Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA, USA.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Dimitrova
authors.forename: Rolf
authors.initials: R
authors.lastname: Fronczek
authors.forename: Janneke
authors.initials: J
authors.lastname: Van der Ploeg
authors.forename: Thomas
authors.initials: T
authors.lastname: Scammell
authors.forename: Shiva
authors.initials: S
authors.lastname: Gautam
authors.forename: Alvaro
authors.initials: A
authors.lastname: Pascual-Leone
authors.forename: Gert Jan
authors.initials: GJ
authors.lastname: Lammers
mesh_terms: D000328:Adult; D001008:Anxiety Disorders / Q000150:complications / Q000175:diagnosis / Q000523:psychology; D056912:Binge-Eating Disorder / Q000150:complications / Q000175:diagnosis / Q000523:psychology; D002385:Cataplexy / Q000150:complications / Q000523:psychology; D003866:Depressive Disorder / Q000150:complications / Q000175:diagnosis / Q000523:psychology; D005260:Female; D006801:Humans; D007175:Impulsive Behavior / Q000150:complications / Q000175:diagnosis / Q000523:psychology; D008297:Male; D001523:Mental Disorders / Q000150:complications* / Q000175:diagnosis / Q000523:psychology*; D009290:Narcolepsy / Q000150:complications* / Q000523:psychology*; D011594:Psychometrics / Q000379:methods / Q000706:statistics & numerical data; D012201:Reward; D012309:Risk-Taking; D011795:Surveys and Questionnaires