title: Lack of effects of guanfacine on executive and memory functions in healthy male volunteers.
abstract: BACKGROUND
  Guanfacine is an alpha2-adrenergic receptor agonist that has been shown to have beneficial effects on working memory and attentional functions in monkeys and in patients with attention deficit hyperactivity disorder.
  
  
  OBJECTIVE
  The aim of this study was to further investigate the cognitive-enhancing properties of guanfacine using an established battery of tasks measuring executive and memory functions.
  
  
  METHODS
  Sixty healthy male volunteers were randomised into three groups. Cognitive testing was performed from +2 to +4 h after double-blind administration of a single oral dose of 1 or 2 mg of guanfacine or placebo.
  
  
  RESULTS
  Systolic blood pressure was significantly reduced by both doses of guanfacine at the end of the testing session. There were no statistically significant effects on any of the cognitive measures. Two trend effects were observed with poorer performance on digit span backward and slower 'Go' reaction times after guanfacine.
  
  
  CONCLUSIONS
  This study found no improvement of prefrontal memory or executive functions after guanfacine. Negative effects on blood pressure and trend effects on digit span backward and go reaction time indicate a mild sedative effect of guanfacine at these doses, possibly via mechanisms of autoreceptor down-regulation.
authors.affiliation: Department of Experimental Psychology, University of Cambridge, Downing Street, Cambridge, CB2 3EB, UK. um207@cam.ac.uk
authors.forename: Ulrich
authors.initials: U
authors.lastname: Müller
authors.forename: Luke
authors.initials: L
authors.lastname: Clark
authors.forename: Minh L
authors.initials: ML
authors.lastname: Lam
authors.forename: Rebecca M
authors.initials: RM
authors.lastname: Moore
authors.forename: C Louise
authors.initials: CL
authors.lastname: Murphy
authors.forename: Nicola K
authors.initials: NK
authors.lastname: Richmond
authors.forename: Ranbir S
authors.initials: RS
authors.lastname: Sandhu
authors.forename: Ingrid A
authors.initials: IA
authors.lastname: Wilkins
authors.forename: David K
authors.initials: DK
authors.lastname: Menon
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Sahakian
authors.forename: Trevor W
authors.initials: TW
authors.lastname: Robbins
mesh_terms: D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy; D001794:Blood Pressure / Q000187:drug effects; D003071:Cognition / Q000187:drug effects; D004311:Double-Blind Method; D016316:Guanfacine / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008568:Memory / Q000187:drug effects*; D011930:Reaction Time / Q000187:drug effects
chemical_list: D016316:Guanfacine