title: Effect of creatine supplementation and sleep deprivation, with mild exercise, on cognitive and psychomotor performance, mood state, and plasma concentrations of catecholamines and cortisol.
abstract: BACKGROUND
  Sleep deprivation has a negative effect on cognitive and psychomotor performance and mood state, partially due to decreases in creatine levels in the brain. Therefore, creatine supplementation should lessen the negative effects of sleep deprivation.
  
  
  OBJECTIVE
  The objective of this study was to examine the effect of creatine supplementation and sleep deprivation, with mild exercise, on cognitive and psychomotor performance, mood state, and plasma concentrations of catecholamines and cortisol.
  
  
  METHODS
  Subjects were divided into a creatine group (n=10) and a placebo group (n=9). They took 5 g of creatine monohydrate or a placebo, dependent on their group, four times a time a day for 7 days, immediately prior to the experiment. The study was double blind. Subjects undertook tests of random movement generation (RMG), verbal and spatial recall, choice reaction time, static balance and mood state pre-test (0 h), after 6, 12 and 24 h of sleep deprivation, with intermittent exercise. They were tested for plasma concentrations of catecholamines and cortisol at 0 and 24 h.
  
  
  RESULTS
  At 24 h, the creatine group demonstrated significantly less change in performance from 0 h (delta) in RMG, choice reaction time, balance and mood state. There were no significant differences between groups in plasma concentrations of catecholamines and cortisol. Norepinephrine and dopamine concentrations were significantly higher at 24 h than 0 h, but cortisol were lower.
  
  
  CONCLUSIONS
  Following 24-h sleep deprivation, creatine supplementation had a positive effect on mood state and tasks that place a heavy stress on the prefrontal cortex.
authors.affiliation: Centre for Sports Science and Medicine, University College Chichester, College Lane, Chichester, West Sussex PO19 6PE, UK. t.mcmorris@ucc.ac.uk
authors.forename: T
authors.initials: T
authors.lastname: McMorris
authors.forename: R C
authors.initials: RC
authors.lastname: Harris
authors.forename: J
authors.initials: J
authors.lastname: Swain
authors.forename: J
authors.initials: J
authors.lastname: Corbett
authors.forename: K
authors.initials: K
authors.lastname: Collard
authors.forename: R J
authors.initials: RJ
authors.lastname: Dyson
authors.forename: L
authors.initials: L
authors.lastname: Dye
authors.forename: C
authors.initials: C
authors.lastname: Hodgson
authors.forename: N
authors.initials: N
authors.lastname: Draper
mesh_terms: D000328:Adult; D000339:Affect / Q000187:drug effects*; D002395:Catecholamines / Q000097:blood; D003071:Cognition / Q000187:drug effects; D003401:Creatine / Q000494:pharmacology* / Q000627:therapeutic use; D019587:Dietary Supplements; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology; D005260:Female; D006185:Habituation, Psychophysiologic; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007858:Learning / Q000187:drug effects*; D008297:Male; D011597:Psychomotor Performance / Q000187:drug effects*; D012892:Sleep Deprivation / Q000188:drug therapy* / Q000503:physiopathology
chemical_list: D002395:Catecholamines; D003401:Creatine; D006854:Hydrocortisone