CSF DIAZEPAM-BINDING INHIBITOR AND SCHIZOPHRENIA - CLINICAL AND BIOCHEMICAL RELATIONSHIPS

Diazepam-binding inhibitor (DBI) is a 9-kD neuropeptide that interacts with the benzodiazepine (BZD) binding sites of the neuronal gamma-ami nobutyric acid type A (GABA(A)) receptor and with the glial mitochondr ial BZD receptor (MBR). We explored the involvement of CSF DBI-LI in s chizophrenia, based on the potential role of GABA in the negative symp toms associated with schizophrenia, the relationship of its receptors with dopamine and norepinephrine release, and the proposed therapeutic efficacy ofBZDs in schizophrenia. Clinical data, CSF DBI-LI and CSF m onoamine measures were obtained in 65 drug-free male chronic (DSM-IIIR ) schizophrenic patients, 53 of whom were also tested prior to haloper idol withdrawal. Following haloperidol withdrawal, CSF DBI-LI increase d significantly. Drug-free CSF DBI-LI did not correlate with CSF monoa mines. CSF DBI-LI was significantly higher in paranoid compared to chr onic undifferentiated schizophrenic patients. The data suggest that DB I may have a symptom modulatory rather than an etiological role in sch izophrenia.