Amine metabolites and neuroendocrine responses related to depression and suicide

5-Hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA) were measured in the lumbar cerebrospinal fluid of 57 drug-free female patients with DSM-III diagnoses of major unipolar or bipolar depression (n = 14), schizophrenic disorder (n = 18), alcohol dependence (n = 13) and a group of other disorders (n = 12). Following lumbar punctures all patients received a dexamethasone suppression test. Fourteen patients had attempted suicide immediately before admission, 4 of them by violent methods. Severity of depression, independent of the diagnosis, was assessed in every patient on the 24-item Hamilton scale. No significant differences in means and variances of amine metabolite or postdexamethasone plasma cortisol concentrations were found among the diagnostic subgroups. Suicidal patients, and in particular those who used violent methods, tended to have lower 5-HIAA, but not HVA, in their CSF; they also more often had non-suppression of cortisol after dexamethasone. Since correlation matrices in the diagnostic subgroups were homogeneous, we calculated partial correlations for the total group: here suicide attempts but not depression, seemed to be significantly correlated with CSF 5-HIAA. Thyrotropin stimulation tests were administered to 6 patients: maximal TSH responses showed a borderline significant correlation with CSF 5-HIAA, and a significant correlation with severity of depression. Neither suicide nor postdexamethasone cortisol levels showed any relation to maximal TSH changes.