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, but not in patients with obsessive-compulsive disorder (OCD) or major depressive disorder (MDD). The purpose of this study was to evaluate the PBR density on platelets from patients with generalized social phobia (GSP).


METHODS
The density (Bmax) and dissociation constant (Kd) of platelet PBRs was determined for 53 medication-free patients with GSP and an equal number of control subjects (NC).


RESULTS
The GSP group was found to have a significantly lower PBR Bmax 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 PBR abnormality with some other anxiety disorders but not with OCD or MDD. PBRs may play a role in the pathophysiology of some anxiety disorders.
Johnson
M R
MR
Department of Psychiatry, Medical University of South Carolina, Charleston 29451, USA.
Marazziti
D
D
Brawman-Mintzer
O
O
Emmanuel
N P
NP
Ware
M R
MR
Morton
W A
WA
Rossi
A
A
Cassano
G B
GB
Lydiard
R B
RB
D000328:Adult; D001792:Blood Platelets / Q000378:metabolism; D005260:Female; D006801:Humans; D007546:Isoquinolines / Q000097:blood / Q000493:pharmacokinetics; D008297:Male; D017933:Peripheral Nervous System / Q000378:metabolism; D010698:Phobic Disorders / Q000378:metabolism*; D011963:Receptors, GABA-A / Q000378:metabolism*
D007546:Isoquinolines; D011963:Receptors, GABA-A; C037850:PK 11195