PLATELET PERIPHERAL-TYPE BENZODIAZEPINE RECEPTOR IN MAJOR DEPRESSION

The peripheral-type benzodiazepine receptor (PBR) plays a major role i n steroidogenesis. This receptor is sensitive to endocrine changes and stress. Antidepressants have been demonstrated to modulate adrenal an d hepatic PBR in rats. To evaluate the relationship between depression and PBR, we measured platelet PBR in untreated depressed patients (n = 14) in comparison to normal controls (n = 13). Platelet PBR density (B-max) and the dissociation constant (k(d)) of the receptor did not d iffer in the patients when compared with normal controls. Furthermore, no correlation was found between B-max values and the severity of the depression (as measured by the Hamilton Depression Rating Scale and B eck Depression Inventory) as well as with the severity of the anxiety (as measured by the Hamilton Anxiety Rating Scale). It seems that majo r depression, in contrast to stress and some anxiety disorders, is not associated with alteration of PBR.