PLATELET 5-HT UPTAKE SITES, LABELED WITH [H-3] PAROXETINE, IN CONTROLS AND DEPRESSED-PATIENTS BEFORE AND AFTER TREATMENT WITH FLUOXETINE ORLOFEPRAMINE

Platelet [H-3] paroxetine binding was measured in 73 depressed patient s and in 64 healthy volunteers. No differences were found in B-max or K-d either overall, or when the 61 depressed subjects who had never re ceived psychotropic drugs were analysed separately. Within the depress ed group, no differences in B-max or K-d were found between subgroups divided on the basis of endogenicity, suicidal thoughts or severity of depression. None of the subgroups differed significantly from control s. Forty of the depressed subjects were retested after 6 weeks' treatm ent with fluoxetine (n = 22) or lofepramine (n = 18). Treatment was no t associated with any change in B-max but a similar and significant in crease in K-d was noted following treatment with either antidepressant . Neither pre- nor post-treatment platelet binding parameters appeared to relate to clinical response to treatment.