Tyrosine Hydroxylase Immunoreactivity in the Locus Coeruleus is Elevated in Violent Suicidal Depressive Patients

This study determined the impact of suicide on the number of noradrenergic neurons of the locus coeruleus in suicidal depressive patients. Noradrenergic neurons were shown by immunostaining tyrosine hydroxylase in the locus coeruleus of 22 non-elderly patients with mood disorders compared to 21 matched normal controls. 11 patients died by suicide & the other 11 died of natural causes. 7 violent suicide victims showed an increased number of tyrosine hydroxylase immunoreactive neurons compared with nonviolent suicide victims & controls. No difference was found between the number of tyrosine hydroxylase immunoreactive neurons in all suicidal patients & controls & between nonsuicidal patients & controls. Results suggested a presynaptic noradrenergic dysregulation in the locus coeruleus related to the level of self-aggression. (69 refs.) JA