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Melatonin response to clonidine administration in depression: indication of presynaptic alpha2-adrenoceptor
T Paparrigopoulos1, C Psarros, J D Bergiannaki
1Department of Psychiatry, Athens University Medical School, Eginition Hospital, 74 Vas. Sofias Ave., 11528, Athens, Greece. egslebath@hol.gr
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.
Method:
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.
Limitation:
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.
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