CIRCADIAN-RHYTHM OF TRYPTOPHAN, SEROTONIN, MELATONIN, AND PITUITARY-HORMONES IN SCHIZOPHRENIA

Circadian rhythm abnormalities have been described mostly with respect to manic-depressive illness; little information is available concerni ng circadian rhythms and schizophrenia or their influence on neurolept ic drugs. We showed previously that the MESOR of dopamine is higher in schizophrenic patients than in healthy subjects and that women who ar e drug-free schizophrenic have lower prolactin MESORs and lower amplit udes than healthy women. We now report the data of a cosinor analysis of tryptophan, serotonin, melatonin, and pituitary hormones in the blo od of 34 healthy subjects, 90 drug-free schizophrenics, and 25 neurole ptic-treated schizophrenic patients. This data indicated a significant phase advance of serum tryptophan, prolactin, and melatonin concentra tions, a trend toward a phase advance in serotonin. Thyroid stimulatin g hormone (TSH), and growth hormone concentrations, and decreases in t he TSH MESORs among patients compared to healthy subjects. These resul ts suggest that circadian changes, such as phase advances and alterati ons in MESOR, are not only present in depression but also in schizophr enia. Although neuroleptic treatment raised the prolactin MESOR and am plitude, it did not elicit any change in circadian rhythmicity among t he other parameters.