Reduced platelet serotonergic responsivity as assessed by dense granule secretion in first-episode psychosis

Objectives: To determine whether blunted serotonergic responsivity, indicated by decreased platelet dense granule secretion (DGS), occurs in neuroleptic-naïve patients with schizophrenia, as observed previously in chronic schizophrenia. Design and methods: Serotonin (5-HT)-amplified DGS was examined in 40 first-episode neuroleptic-naïve patients (24 with schizophrenia and 16 with mood disorders) and 24 healthy subjects. Results: Healthy controls showed robustly increased DGS. Schizophrenic patients showed very modest DGS increases; mood disorder patients showed intermediate response. Conclusions: Blunted DGS appears to a characteristic of schizophrenia that is observed in the treatment-naïve condition.