CSF diazepam-binding inhibitor concentrations in panic disorder.

Diazepam-binding inhibitor (DBI) is a neuropeptide that has been detected in the brain and cerebrospinal fluid (CSF). Previous studies have suggested the possible role of DBI as a potential endogenous anxiogenic ligand modulating GABAergic transmission at the benzodiazepine-GABA receptor complex. The measurement of DBI immunoreactivity (DBI-IR) in CSF of panic-disorder patients and normal controls was undertaken to assess whether there were differences in the CSF concentration of this peptide to assess possible relationships with other monoamines and peptides. Lumbar CSF was obtained from 18 panic patients (4 men, 14 women) and 9 controls (5 men, 4 women). As a group, no significant differences were found between panic patients' CSF concentration of DBI-IR (1.12 +/- 0.27 pmol/mL) and normal volunteers (1.23 +/- 0.27 pmol/mL). No gender differences were demonstrated. However, we did find a positive correlation between CSF levels of DBI and CSF corticotropin releasing hormone (CRH) in our panic patients.