Depressed patients who had attempted suicide (N = 19) had significantly
lower CSF homovanillic acid (HVA) levels than patients who had not
attempted suicide (N = 8) and control subjects (N = 41). Intergroup levels
of 5-hydroxyindoleacetic acid (5-HIAA) were not significantly different.
The ratio of CSF HVA to CSF 5-HIAA was significantly lower in both patient
groups than in control subjects, and patients who had attempted suicide had
CSF HVA/5-HIAA ratios that were nearly 50% those of the control subjects.
The combinations of nonsuppression on the dexamethasone suppression test
and either a low CSF HVA level or a low CSF HVA/5-HIAA ratio were
significantly more common among patients who had attempted suicide than
among those who had not.