ABNORMAL PERIPHERAL BENZODIAZEPINE RECEPTOR DENSITY ASSOCIATED WITH GENERALIZED SOCIAL PHOBIA

Background: Peripheral benzodiazepine receptors (PBRs) are involved in regulating stress responses. Abnormally low numbers of platelet PBRs have been found in patients with panic disorder, posttraumatic stress disorder, and generalized anxiety disorder, bur not in patients with o bsessive-compulsive disorder (OCD) or major depressive disorder (MDD). The purpose of this study was to evaluate the PER density on platelet s from patients with generalized social phobia (GSP). Methods: The den sity (B-max) and dissociation constant (K-d) of platelet PBRs was dete rmined for 53 medication-free patients with GSP and an equal number of control subjects (NC). Results: The GSP group was found to have a sig nificantly lower PER B-max than the NC group (GSP = 2764 +/- 1242 vs. NC = 4327 +/- 1850 fmol/mg protein, df = 1,100, F = 22.7, p = .00001). Conclusions: GSP shares this PER abnormality with some other anxiety disorders but nor with OCD or MDD. PBRs may play a role in the pathoph ysiology of some anxiety disorders. (C) 1998 Society of Biological Psy chiatry.