The specificity of platelet glutamate receptor supersensitivity in psychotic disorders

Hypoglutamatergic function is implicated in the pathogenesis of schizophren ia, and supersensitivity of platelet NMDA receptors has been reported in sc hizophrenia. The aim of this study was to examine the platelet glutamate re ceptor sensitivity in patients with schizophrenia (n=12), mania with psycho tic features (n=10) and depression with psychotic features (n=10) and match ed controls (n=12) in order to assess if this is a marker of schizophrenia or occurs in other psychotic conditions. Glutamate receptor sensitivity was assessed using the intracellular calcium response to glutamate measured wi th spectroflourometry. The percentage response of the schizophrenic and dep ressed psychotic subjects to glutamate stimulation was significantly greate r than control subjects (p<0.005). The mania with psychotic features group was not significantly different to controls. This data suggests that platel et glutamate receptors may be supersensitive in schizophrenia and depressio n with psychotic features. Furthermore, the platelet may be a possible peri pheral marker of glutamate function in schizophrenia and depression with ps ychotic features.