Delta-sleep inducing peptide in cerebrospinal fluid from schizophrenics, depressives and healthy volunteers.

CSF levels of DSIP was measured in healthy volunteers and in hospitalized patients with schizophrenia or major depressive disorders. Both patient groups had significantly lower CSF levels of DSIP than the healthy volunteers. There was a tendency for lower CSF levels of DSIP in female compared to male schizophrenics. Neuroleptic treatment did not significantly affect those levels. The levels of DSIP in CSF tended to be inversely correlated to the sleep disturbancy scores in the depressed patients.