Neuropeptides in relation to suicidal behavior in depression

Neuropeptides were examined in relation to suicidal behavior and its repetition in depression. There were no significant differences between depressed patients who had or had not attempted suicide for cerebrospinal fluid (CSF) concentrations of neuropeptide Y, somatostatin, diazepam-binding inhibitor, GABA, or corticotropin releasing hormone. A 5-year follow-up was carried out. There were no significant differences between depressed patients who did or did not reattempt suicide during the follow-up or who had never attempted for CSF concentrations of any of the neuropeptides measured. These negative results suggest that these neuropeptides are probably not major determinants of suicidal behavior or its repetition in depression.