title: Melatonin response to clonidine administration in depression: indication of presynaptic alpha2-adrenoceptor dysfunction.
abstract: BACKGROUND
  The aim of this study was to investigate alpha2-adrenoceptor sensitivity in depression, by using melatonin response to clonidine administration as an index of alpha2-adrenoceptor functioning.
  
  
  METHODS
  35 depressed subjects and 41 healthy controls were assessed for overnight urinary melatonin pre- and post-administration of oral clonidine.
  
  
  RESULTS
  Administration of clonidine significantly reduced melatonin concentrations in depressed patients but not in control subjects.
  
  
  CONCLUSIONS
  A single oral dose (0.15 mg) of clonidine was administered.
  
  
  CONCLUSIONS
  Further indication is provided for presynaptic alpha2-adrenoceptor dysfunction in depression with the application of an alternative pharmacological challenge method.
authors.affiliation: Department of Psychiatry, Athens University Medical School, Eginition Hospital, 74 Vas. Sofias Ave., 11528, Athens, Greece. egslebath@hol.gr
authors.forename: T
authors.initials: T
authors.lastname: Paparrigopoulos
authors.forename: C
authors.initials: C
authors.lastname: Psarros
authors.forename: J D
authors.initials: JD
authors.lastname: Bergiannaki
authors.forename: E
authors.initials: E
authors.lastname: Varsou
authors.forename: U
authors.initials: U
authors.lastname: Dafni
authors.forename: C
authors.initials: C
authors.lastname: Stefanis
mesh_terms: D000328:Adult; D003000:Clonidine; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008550:Melatonin / Q000652:urine*; D008875:Middle Aged; D018341:Receptors, Adrenergic, alpha-2 / Q000502:physiology*; D017661:Receptors, Presynaptic / Q000502:physiology*; D012016:Reference Values
chemical_list: D018341:Receptors, Adrenergic, alpha-2; D017661:Receptors, Presynaptic; D008550:Melatonin; D003000:Clonidine