Enhancement of the prolactin response to d-fenfluramine in drug-naive schizophrenic patients

Background. We wished to investigate central serotonergic function in untreated schizophrenia. Method. Thirteen drug-naive, DSM-III-R schizophrenic patients were compared with sex, race, age, weight and menstrual phase matched controls. Plasma prolactin in and cortisol responses to a specific serotonergic probe, d-fenfluramine, were measured along with BPRS ratings. Results. Prolactin responses were enhanced in schizophrenic patients compared to controls (P<0.05) and were correlated positively with BPRS items for depression, anxiety and guilt. Baseline cortisol was also raised in those with schizophrenia (P<0.001). Conclusions. Central serotonergic tone may be raised in acute, drug-naive schizophrenia and may be associated with the presence of affective symptomatology.