Adrenergic status in anxiety disorders: Platelet alpha2-adrenergic receptor binding, blood pressure, pulse, and plasma catecholamines in panic and generalized anxiety disorders patients and in normal subjects,

Abstract

In order to evaluate adrenergic function in anxiety disorders, platelet alpha2-adrenergic binding parameters and supine and standing blood pressure, pulse, and venous plasma epinephrine and norepinephrine were determined in patients with panic attacks or generalized anxiety disorder and in normal subjects. The maximum number of binding sites (Bmax) for the partial agonist tritiated clonidine was significantly lower for both patient groups than for normal subjects, and the Bmax for the antagonist tritiated yohimbine was significantly lower for panic patients. There were no other substantive differences across groups. Prior exposure to psychotrophic drugs might account for the results for clonidine binding, but not for yphimbine. The Bmax for clonodine was correlated with norepinephrine increases upon standing and, for panic patients, with the severity of full unexpected panic attacks. These data provide further evidence of adrenergic receptor abnormalities in people with anxiety disorders.