To the Editor.—
Ceruletide, a synthetic decapeptide of cerulein, seems to act as a neuromodulator that influences the dopaminergic system,1-3 and it has recently been reported to improve mood and drive in patients with chronic schizophrenia.4,5In an open study, we investigated six patients with chronic schizophrenia who had been admitted because of an acute exacerbation of their illness. After subsidence of the acute psychotic symptoms, all patients suffered from a depressive syndrome with total lack of impetus. They were treated with various neuroleptics (mean daily dosage, 356 mg of chlorpromazine equivalents) and then received 3 μg/kg of ceruletide intramuscularly (IM) two times (on days 0 and 14). Psychopathology was rated on the Brief Psychiatric Rating Scale (BPRS) on days 1, 7, 14, 21, and 28. All the patients' conditions improved significantly by the BPRS total score, with a maximum improvement at day 28 (day 1, x = 52,