Young et al1 reported in the August 1991 issue of the Archives on fast-feedback inhibition of β-endorphin/β-lipotropin by hydrocortisone infusion that occurred in 16 control subjects but not in 16 depressed patients. Their data suggested a decreased sensitivity to glucocorticoid fast feedback in depression, and complemented studies demonstrating decreased sensitivity to delayed feedback by dexamethasone.
Recently we described the effects of metyrapone on pro-gamma—melanocyte-stimulating-hormone (MSH), corticotropin (ACTH), and cortisol plasma levels in 30 drugfree male patients who met the DSM-III-R criteria for a major depressive episode and 21 healthy control subjects.2The availability of a specific radioimmunoassay (RIA) for β-endorphin with no significant cross-reactivity with β-lipotropin, γ-endorphin, or metenkephalin (Peninsula Laboratories, Belmont, Calif) led us subsequently to evaluate β-endorphin and its response to metyrapone. Details of the patient population, informed consent, protocol, and methods were provided.2 The intra-assay and interassay coefficients of variation of our β-endorphin RIA
Morphy MA, Fava GA, Sonino N. β-Endorphin Responsiveness in Depression. Arch Gen Psychiatry. 1993;50(5):406. doi:10.1001/archpsyc.1993.01820170092011