Sex differences, season of birth and platelet 5-HT levels in schizophrenicpatients

Similar occurrence of schizophrenia was observed in men and women independe nt of their season of birth. Platelet 5-HT concentration was determined in 116 healthy control subjects (61 male and 55 female) and 152 patients with schizophrenia (96 male and 56 female). Platelet 5-HT concentration was sign ificantly higher in male than in female healthy persons and schizophrenic p atients. Male and female healthy subjects born in different seasons had sim ilar platelet 5-HT concentrations, whereas schizophrenic patients with diff erent birth-seasons had significantly different platelet 5-HT concentration s. The highest platelet 5-HT levels were observed in both male and female s chizophrenic patients born in winter when compared to matched healthy contr ols. Male schizophrenic patients born in winter had higher platelet 5-HT le vels than schizophrenic men born in spring and summer. Female schizophrenic patients born in winter had higher platelet 5-HT than schizophrenic women born in all other seasons. These results indicated sex differences in plate let 5-HT levels in healthy persons and schizophrenic patients. The relation ship between season of the birth and platelet 5-HT concentration observed o nly in schizophrenic patients added further support to the presumption that schizophrenia is connected with a disturbance in the central serotoninergi c system.