NMDA GLUTAMATERGIC RECEPTORS, LABELED WITH [H-3] MK-801, IN BRAIN SAMPLES FROM DRUG-FREE DEPRESSED SUICIDES

Glutamate receptors of the NMDA-subtype were quantitated by binding of [H-3]dizocilpine maleate (MK-801) in nine brain regions from 22 suicide victims (20-60 yr), with a firm retrospective diagnosis of depression, who had not recently received antidepressant drugs, and 20 age- and sex-matched controls. [H-3]MK-801-binding did not differ between suicides and controls in any region studied. Suicides who died violently did not differ from non-violent suicides and controls. A significative negative correlation was found between age and NMDA receptor-binding in the frontal cortex of suicide victims, but not in controls. This preliminary study provides little evidence for an important role of NMDA-binding sites in the pathophysiology of depression.