DIFFERENTIAL AGE-RELATED LOSS OF PIGMENTED LOCUS-COERULEUS NEURONS INSUICIDES, ALCOHOLICS, AND ALCOHOLIC SUICIDES

We previously reported fewer locus coeruleus (LC) neurons in both suic ide victims and alcoholics than among a group of nonpsychiatric contro ls. In the present paper we examine the rate of decline in the number of LC neurons with age, looking for possible differential rates among suicide victims, alcoholics, and controls. We also compare these group s with a group of alcoholics who died by suicide, and consider the eff ects of sex, race, and postmortem interval. LC neuron counts were obta ined from a total of 32 subjects. In all groups, the number of neurons decreased with age, but by roughly age 40 the average LC count among the three suicide and/or alcoholic groups was lower than among control s. The rate of LC neuron loss was greater among suicides than among co ntrols, but the rate of loss among alcoholics who were at least 30 yea rs old was the same as that among the controls. Our group of alcoholic suicides had counts that were statistically indistinguishable from th ose of suicides. Differences among groups appear to be mast pronounced in the middle third of the LC. Further studies are needed to determin e the mechanisms of noradrenergic neuron loss and whether it is associ ated with an underlying major depression in suicide victims, or acquir ed after a period of excessive alcohol consumption.