title: Reward learning deficits in Parkinson's disease depend on depression.
abstract: BACKGROUND
  Depression is one of the most common and debilitating non-motor symptoms of Parkinson's disease (PD). The neurocognitive mechanisms underlying depression in PD are unclear and treatment is often suboptimal.
  
  
  METHODS
  We investigated the role of striatal dopamine in reversal learning from reward and punishment by combining a controlled medication withdrawal procedure with functional magnetic resonance imaging in 22 non-depressed PD patients and 19 PD patients with past or present depression.
  
  
  RESULTS
  PD patients with a depression (history) exhibited impaired reward v. punishment reversal learning as well as reduced reward v. punishment-related BOLD signal in the striatum (putamen) compared with non-depressed PD patients. No effects of dopaminergic medication were observed.
  
  
  CONCLUSIONS
  The present findings demonstrate that impairments in reversal learning from reward v. punishment and associated striatal signalling depend on the presence of (a history of) depression in PD.
authors.affiliation: Donders Institute for Brain,Cognition and Behaviour,Centre for Cognitive Neuroimaging,Radboud University,Nijmegen,The Netherlands.
authors.forename: M H M
authors.initials: MHM
authors.lastname: Timmer
authors.affiliation: Donders Institute for Brain,Cognition and Behaviour,Centre for Cognitive Neuroimaging,Radboud University,Nijmegen,The Netherlands.
authors.forename: G
authors.initials: G
authors.lastname: Sescousse
authors.affiliation: Donders Institute for Brain,Cognition and Behaviour,Centre for Cognitive Neuroimaging,Radboud University,Nijmegen,The Netherlands.
authors.forename: M E
authors.initials: ME
authors.lastname: van der Schaaf
authors.affiliation: Department of Neurology and Parkinson Center Nijmegen (ParC),Radboud University Medical Center,Nijmegen,The Netherlands.
authors.forename: R A J
authors.initials: RAJ
authors.lastname: Esselink
authors.affiliation: Donders Institute for Brain,Cognition and Behaviour,Centre for Cognitive Neuroimaging,Radboud University,Nijmegen,The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Cools
mesh_terms: D000368:Aged; D003866:Depressive Disorder / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011678:Punishment; D011699:Putamen / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012193:Reversal Learning / Q000502:physiology*; D012201:Reward
keywords: Parkinson's disease; depression; dopamine; functional MRI; learning