Increased density of mu-opioid receptors in the postmortem brain of suicide victims.

The biochemical status of mu-opioid receptors in suicide was evaluated by [3H]DAGO specific binding in postmortem human brains from 15 suicide victims and 15 controls. The density (Bmax) in frontal cortex and thalamus was directly correlated with age. In the frontal cortex and caudate but not in the thalamus of suicide victims the density of mu-opioid receptors was 36-39% higher than in controls. KD values in suicide victims were similar to those in control group (range 1.4-2.2 nM). The results suggest an increase of mu-opioid receptors in suicide associated to some brain areas showing the mu2-opioid receptor subtype.