Peripheral benzodiazepine receptor messenger RNA is decreased in lymphocytes of generalized anxiety disorder patients.

Background: The aim of this study was to assess whether the decrease of peripheral benzodiazepine receptor (pBR) number in peripheral blood mononuclear cells (PBMC), previously observed in patients with generalized anxiety disorder, is paralleled by changes in the relative content of messenger RNA (mRNA) encoding pBR. Methods: Eight patients with a DSM-III-R diagnosis of generalized anxiety disorder were examined before, during, and after 2′-chloro-N-desmethyl-diazepam treatment. Eight healthy subjects were analyzed in parallel. The relative content of pBR mRNA was determined by reverse-transcriptase-polymerase chain reaction, using β -actin as internal standard. Kinetic binding properties of pBR were measured using 3 H-PK11195 as a ligand. Results: pBR and pBR mRNA were significantly decreased in untreated generalized anxiety disorder patients as compared to controls (by 45% and 70%, respectively). Both pBR density and mRNA levels returned to control values during treatment or after withdrawal, which also coincided with recovery from anxiety. Conclusions: These results suggest that the turnover rate of pBR is reduced in PBMC of generalized anxiety disorder patients, and that this change occurs at the transcriptional level.