Effects of haloperidol on somatostatin-like immunoreactivity in the CSF of Schizophrenic patients.

The levels of somatostatin-like immunoreactivity (SLI) were determined in the cerebrospinal fluid (CSF) of 14 schizophrenic patients before and after 3 weeks on haloperidol treatment. Baseline levels of SLI correlated negatively with psychopathological items on the Brief Psychiatric Rating Scale related to psychotic productivity. SLI levels increased after haloperidol treatment, but this increase did not correlate with psychopathological improvement. A difference in the ratio of larger and smaller molecular forms of the peptide was found before and after treatment. The drug-free samples showed a preponderance of the larger molecular forms, resulting in a ratio of 4:1, whereas the haloperidol-treated samples showed an equal distribution of both species.