Melatonin response to clonidine administration in depression: indication of presynaptic alpha2-adrenoceptor dysfunction.
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.
Paparrigopoulos
T
T
Department of Psychiatry, Athens University Medical School, Eginition Hospital, 74 Vas. Sofias Ave., 11528, Athens, Greece. egslebath@hol.gr
Psarros
C
C
Bergiannaki
J D
JD
Varsou
E
E
Dafni
U
U
Stefanis
C
C
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
D018341:Receptors, Adrenergic, alpha-2; D017661:Receptors, Presynaptic; D008550:Melatonin; D003000:Clonidine