Decreased density of benzodiazepine receptors in lymphocytes of anxious patients: reversal after chronic diazepam treatment

Peripheral‐type benzodiazepine receptors were measured in human circulating lymphocytes using 3H‐PK 11195 as specific ligand. In a group of outpatients with anxiety disorders a significant decrease of receptor density (– 37%) was found compared with age‐matched controls. In these patients long‐term diazepam treatment restored binding density to normal levels: the effect persisted after drug withdrawal. Acute i.v. diazepam administration did not change receptor density. The observed receptor changes could reflect a down‐regulation phenomenon and indicate that lymphocyte function reflect central nervous events.