DECREASED NOCTURNAL SECRETION OF MELATONIN IN DRUG-FREE SCHIZOPHRENICS - NO CHANGE AFTER SUBCHRONIC TREATMENT WITH ANTIPSYCHOTICS

To evaluate the biosynthetic activity of the pineal gland in schizophr enia, the circadian rhythm of plasma melatonin was investigated in 9 d rug-free chronic schizophrenics and in matched healthy subjects. In 7 of the patients, the 24-hour secretory pattern of the pineal hormone w as reassessed after 10 weeks of treatment with antipsychotic drugs. In drug-free schizophrenics, the nocturnal increase in plasma melatonin levels was significantly blunted as compared to healthy subjects (p < 0.0001). Chronic treatment with antipsychotic drugs significantly impr oved psychotic symptomatology, but did not change the secretory patter n of melatonin. These data show that the biosynthetic activity of the pineal gland is impaired in chronic schizophrenia and that successful treatment with antipsychotic drugs does not go parallel with changes i n the production of melatonin.