Hyperserotonemia and platelet serotonin uptake and release in schizophrenia and affective disorders

Abstract
Platelet serotonin [5-HT] concentrations were significantly elevated in patients with chronic schizophrenia and in patients with chronic schizophrenia and in patients with bipolar major depressive disorder. High-affinity 5-HT uptake was significantly reduced only in patients with bipolar major depressive disorder. Thrombin-induced release of 5-HT from platelets in any patient group was not different from that of normal control subjects. Platelet 5-HT storage in chronic schizophrenic patients was also not different from that in normal control subjects. These platelet findings could not be explained by age, sex or medication variables. Evidently, the pharmacodynamics of platelet 5-HT may be different in chronic schizophrenia than in bipolar major depressive disorder.