ALTERED PLATELET PERIPHERAL-TYPE BENZODIAZEPINE RECEPTOR IN POSTTRAUMATIC-STRESS-DISORDER

Peripheral-type benzodiazephine receptors (PBX) are involved in steroi dogenesis and are sensitive to stress. Reduced platelet PBX density ha s been demonstrated in generalized anxiety disorder (GAD), but not in obsessive-compulsive disorder (OCD). We extended this observation to a nother anxiety disorder namely, posttraumatic stress disorder (PTSD). Eighteen post-Persian Gulf War PTSD patients and 17 age- and sex-match ed controls were included in the study. All subjects were evaluated us ing the Structured Clinical Interview for DSM-III-R-Patient Version. T he severity of symptoms teas assessed using the DSM-III-X scale for PT SD, the Impact of Event Scale, the Beck Depression Inventory, and the State-Trait Anxiety Inventory. [H-3]PK 11195 was used to label platele t PBR. All psychological parameters (except trait anxiety) were higher in PTSD patients compared to controls. Decreased platelet PBX density (-62%; p<.001) was observed in the PTSD patients compared to controls . The reduction in PBX observed in PTSD patients was in accordance wit h the findings in GAD patients, but differed from those obtained in OC D patients. It is possible that the receptoral downregulation is an ad aptive response aimed at preventing chronic overproduction of glucocor ticoids in hyperarousal states.