title: Reward-related decision making in older adults: relationship to clinical presentation of depression.
abstract: OBJECTIVE
  Impairment in reward processes has been found in individuals with depression and in the aging population. The purpose of this study was twofold: (1) to use an affective neuroscience probe to identify abnormalities in reward-related decision making in late-life depression; and (2) to examine the relationship of reward-related decision making abnormalities in depressed, older adults to the clinical expression of apathy in depression. We hypothesized that relative to older, healthy subjects, depressed, older patients would exhibit impaired decision making and that apathetic, depressed patients would show greater impairment in decision making than non-apathetic, depressed patients.
  
  
  METHODS
  We used the Iowa Gambling Task to examine reward-related decision making in 60 non-demented, older patients with non-psychotic major depression and 36 older, psychiatrically healthy participants. Apathy was quantified using the Apathy Evaluation Scale. Of those with major depression, 18 individuals reported clinically significant apathy, whereas 42 participants did not have apathy.
  
  
  RESULTS
  Older adults with depression and healthy comparison participants did not differ in their performance on the Iowa Gambling Task. However, apathetic, depressed older adults adopted an advantageous strategy and selected cards from the conservative decks compared with non-apathetic, depressed older adults. Non-apathetic, depressed patients showed a failure to adopt a conservative strategy and persisted in making risky decisions throughout the task.
  
  
  CONCLUSIONS
  This study indicates that apathy in older, depressed adults is associated with a conservative response style on a behavioral probe of the systems involved in reward-related decision making. This conservative response style may be the result of reduced sensitivity to rewards in apathetic individuals.
authors.affiliation: Department of Psychiatry, Institute of Geriatric Psychiatry, Weill Cornell Medical College, White Plains, NY, USA.
authors.forename: Amanda R
authors.initials: AR
authors.lastname: McGovern
authors.forename: George S
authors.initials: GS
authors.lastname: Alexopoulos
authors.forename: Genevieve S
authors.initials: GS
authors.lastname: Yuen
authors.forename: Sarah Shizuko
authors.initials: SS
authors.lastname: Morimoto
authors.forename: Faith M
authors.initials: FM
authors.lastname: Gunning-Dixon
mesh_terms: D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D057565:Apathy; D016022:Case-Control Studies; D003657:Decision Making; D003865:Major Depressive Disorder / Q000523:psychology*; D005260:Female; D005715:Gambling; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012201:Reward
keywords: apathy; decision making; late-life depression; reward