Binding of [3H]paroxetine to platelets of depressed patients: seasonal differences and effects of diagnostic classification.

[3H]Paroxetine is a more reliable ligand for studying the serotonin (5-HT) transporter complex than [3H]imipramine. The present study investigates [3H]paroxetine binding to platelets in 54 depressed in-patients (18 minor, 16 simple major and 20 melancholic depressed patients) and 16 healthy controls. There were no significant differences in maximal number of binding sites between depressed subjects and normal controls. There was no correlation between [3H]paroxetine binding to platelet membranes and severity of depression. [3H]Paroxetine binding to platelets was significantly higher in spring than in summer, fall and winter.