title: Anhedonia is associated with blunted reward sensitivity in first-degree relatives of patients with major depression.
abstract: BACKGROUND
  Anhedonia is a cardinal feature of major depression and is hypothesized to be driven by low motivation, in particular blunted reward sensitivity. It has been suggested to be a marker that represents a genetic predisposition to this disorder. However, little is known about the mechanisms underlying this heightened risk in unaffected first-degree relatives of patients with major depression. We previously demonstrated abnormal reward biases in acutely depressed patients. The present study aimed to examine the development of reward bias in first-degree relatives of patients with major depression.
  
  
  METHODS
  Forty-seven first-degree relatives of patients with major depression (26 females, age 18-52) and 60 healthy controls with no family history of depression (34 females, age 21-48) were recruited. A probabilistically rewarded difficult visual discrimination task, in which participants were instructed about the contingencies, was used to assess blunted reward sensitivity. A response bias towards the more frequently rewarded stimulus (termed "reward bias") was the primary outcome variable in this study. Participants also completed self-reported measures of anhedonia and depressive symptoms.
  
  
  RESULTS
  Compared with the control group, relatives of patients with major depression with sub-clinical depressive symptoms displayed a blunted reward bias. Relatives without symptoms displayed largely intact motivational processing on both self-report and experimental measures. The degree of anhedonia was associated with attenuated reward bias in first-degree relatives of patients with major depression, especially in those with sub-clinical symptoms.
  
  
  CONCLUSIONS
  The study did not include a depressed patient group, which restricted our ability to interpret the observed group differences.
  
  
  CONCLUSIONS
  Blunted reward sensitivity may be largely manifested in a subgroup of relatives with high levels of depressive symptoms.
authors.affiliation: Faculty of Health Management, Guangzhou Medical University, Guangzhou, China; Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China; Guangzhou Psychiatric Hospital, the Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Wen-Hua
authors.initials: WH
authors.lastname: Liu
authors.affiliation: Institute of Cognitive Neuroscience, University College London, UK.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Roiser
authors.affiliation: Guangzhou Psychiatric Hospital, the Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Ling-Zhi
authors.initials: LZ
authors.lastname: Wang
authors.affiliation: Guangzhou Psychiatric Hospital, the Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Yu-Hua
authors.initials: YH
authors.lastname: Zhu
authors.affiliation: Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Huang
authors.affiliation: Menzies Health Institute Queensland and School of Applied Psychology, Griffith University, Gold Coast, Australia.
authors.forename: David L
authors.initials: DL
authors.lastname: Neumann
authors.affiliation: Menzies Health Institute Queensland and School of Applied Psychology, Griffith University, Gold Coast, Australia.
authors.forename: David H K
authors.initials: DHK
authors.lastname: Shum
authors.affiliation: Castle Peak Hospital, Hong Kong Special Administrative Region, China.
authors.forename: Eric F C
authors.initials: EFC
authors.lastname: Cheung
authors.affiliation: Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China. Electronic address: rckchan@psych.ac.cn.
authors.forename: Raymond C K
authors.initials: RCK
authors.lastname: Chan
mesh_terms: D000328:Adult; D059445:Anhedonia; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000523:psychology*; D005195:Family Relations; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009042:Motivation; D012201:Reward; D057566:Self Report; D055815:Young Adult
keywords: Anhedonia; Depression; Reward; Risk factors