Decreased beta-adrenergic receptors in the leukocytes of depressed patients.

We studied beta-adrenergic receptor binding, using 125I-cyanopindolol as the ligand, in the leukocyte membranes of depressed patients, schizophrenic patients, and normal control subjects during a drug-free period. We also determined plasma cortisol levels and dexamethasone suppression in these subjects. The maximum number of beta-adrenergic receptor sites (Bmax) was significantly lower in depressed patients than in normal control subjects. Nonsuppressors on the dexamethasone suppression test tended to have a decreased Bmax in comparison to suppressors. There was no significant difference in the Kd between any of the groups. These results indicate that decreased beta-adrenergic receptor responsiveness in the leukocytes of depressed patients is probably due to a decrease in the number of beta-adrenergic receptor sites.