Serotonergic measures in suicide brain: 5-HT_1A binding sites in frontal cortex of suicide victims

The density of 5-HT_1A binding using³H-8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) as binding ligand, was studied in human frontal cortex of suicide victims and normal controls who died due to medical disease or accidentally. There was no difference in the maximum number of binding site (B_max) or K_d (an inverse measure of affinity) of 5-HT_1A receptor binding sites between normal controls and the entire group of suicide victims. However, nonviolent suicides had significantly higher B_max (22-25%) compared to both controls and violent suicides. A negative correlation between age and B_max of 5-HT_1A binding sites was found in male controls but not in female controls or suicide victims. This relationship was less apparent among the male controls over age 60.