title: Salivary cortisol levels in Parkinson's disease and its correlation to risk behaviour.
abstract: OBJECTIVE
  To investigate salivary cortisol samples in patients with Parkinson's disease (PD) with and without impulsive compulsive behaviours (ICB) during a risk task.
  
  
  METHODS
  Salivary cortisol levels were measured in 13 PD patients without ICB (PD-ICB) and in 15 PD patients with ICB (PD+ICB) before, after medication and throughout the day, and were compared with results with 14 healthy controls. All participants also performed a gambling task to assess risk taking behaviour.
  
  
  RESULTS
  Significantly higher diurnal cortisol levels were found in the PD-ICB group compared with healthy controls but no differences were seen between the PD+ICB and the control group. Increased cortisol levels were significantly correlated with increased risk taking in PD+ICB patients but no interaction was found in the PD-ICB group.
  
  
  CONCLUSIONS
  The findings are in keeping with previous studies which have linked low cortisol levels with antisocial behaviour. The higher cortisol levels during the risk task in the PD+ICB group are consistent with reports in pathological gamblers during gambling and addicts during drug abuse. The results support the hypothesis that cortisol plays an important role in risk taking in ICBs.
authors.affiliation: Reta Lila Weston Institute of Neurological Studies and Queen Square Brain Bank for Neurological Diseases, University College London, London, UK.
authors.forename: Atbin
authors.initials: A
authors.lastname: Djamshidian
authors.forename: Sean S
authors.initials: SS
authors.lastname: O'Sullivan
authors.forename: Andrew
authors.initials: A
authors.lastname: Papadopoulos
authors.forename: Paul
authors.initials: P
authors.lastname: Bassett
authors.forename: Karen
authors.initials: K
authors.lastname: Shaw
authors.forename: Bruno B
authors.initials: BB
authors.lastname: Averbeck
authors.forename: Andrew
authors.initials: A
authors.lastname: Lees
mesh_terms: D000368:Aged; D002940:Circadian Rhythm / Q000502:physiology; D003192:Compulsive Behavior / Q000097:blood / Q000523:psychology; D005260:Female; D005715:Gambling / Q000097:blood / Q000523:psychology; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007175:Impulsive Behavior / Q000097:blood / Q000523:psychology; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D009460:Neurologic Examination; D010300:Parkinson Disease / Q000097:blood* / Q000523:psychology; D012309:Risk-Taking; D012463:Saliva / Q000737:chemistry; D013223:Statistics as Topic
chemical_list: D006854:Hydrocortisone