title: Altered risk-aversion and risk-taking behaviour in patients with Alzheimer's disease.
abstract: OBJECTIVE
  Normal individuals are risk averse for decisions framed as gains but risk taking for decisions framed as losses. This framing effect is supposed to be attenuated in Alzheimer's disease (AD) patients. We investigated the effects of highlighting rewards versus highlighting punishments on the risky decision-making of AD patients.
  
  
  METHODS
  Fourteen mild to moderate AD patients (Mini-Mental Status Examination score, 11-23; Clinical Dementia Rating, 1-2) and 16 healthy volunteers were recruited for the study. Subjects completed a computerized task on risky decision-making in which mathematically equivalent dilemmas were presented in terms of opportunities to gain monetary rewards ('positive frame') or avoid suffering losses ('negative frame').
  
  
  RESULTS
  As expected, AD patients chose more risky options under the positive frame than the negative frame, contrary to the control group (Z =-2.671, P= 0.007). The normal difference in the distribution of risky choices between positively and negatively framed dilemmas was significantly reduced in the AD group after we adjusted for years of education, mean age and depression (F= 5.321, P= 0.030). Deliberation time did not differ significantly between the two groups.
  
  
  CONCLUSIONS
  These results suggest that AD patients making high-risk choices is associated with attenuated sensitivity to the emotional frames that highlight rewards or punishments, possibly reflecting altered evaluations of prospective gains and losses.
authors.affiliation: Department of Psychiatry, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Juwon
authors.initials: J
authors.lastname: Ha
authors.forename: Eun-Jin
authors.initials: EJ
authors.lastname: Kim
authors.forename: Sewon
authors.initials: S
authors.lastname: Lim
authors.forename: Dong-Won
authors.initials: DW
authors.lastname: Shin
authors.forename: Yeo-Jin
authors.initials: YJ
authors.lastname: Kang
authors.forename: Seung-Min
authors.initials: SM
authors.lastname: Bae
authors.forename: Hyung-Kun
authors.initials: HK
authors.lastname: Yoon
authors.forename: Kang-Seob
authors.initials: KS
authors.lastname: Oh
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000523:psychology*; D003657:Decision Making; D005260:Female; D006801:Humans; D007723:Korea; D008297:Male; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D012201:Reward; D012309:Risk-Taking