Platelet serotonin functions in untreated major depression

Abstract

The uptake of [ 14C]5-HT, [ 3H]paroxetine and [ 3H]LSD binding was determined in platelets from 30 untreated patients with major depression and compared with corresponding variables from 30 healthy age-, sex- and season-matched control subjects. The maximum velocity ( V max) for the 5-HT uptake was significantly decreased in patients ( P=0.014) compared to control subjects. Depressed women had significantly lower V max than female control subjects. In men, V max did not differ between patients and control subjects. V max was significantly lower in male inpatients compared with male outpatients ( P=0.05). The density ( B max) of 5-HT uptake sites was found to be significantly increased in patients ( P<0.05) compared to control subjects and male patients had significantly higher B max than male control subjects, but there was no difference between female control subjects and female patients. No significant difference was found in B max of 5-HT 2-receptors between patients and control subjects. A positive correlation was found between B max of 5-HT 2-uptake sites and the degree of anxiety and between B max of 5-HT 2 receptors and MADRS scores. B max of 5-HT 2-receptors was positively correlated with the degree of suicidality. The results in the present study indicate that there may be a gender difference in serotonergic dysfunction in depression.