The elevation of plasma beta-endorphin levels in major depression

Day-time plasma beta-endorphin/beta-lipotrophic hormone (beta-ENDO/beta-LPH), ACTH and cortisol have been determined in 26 patients with major depression and 25 controls. beta-ENDO/beta-LPH and cortisol were significantly elevated in patients, while ACTH was not. Cortisol levels were significantly negatively correlated with age in controls as were beta-ENDO/beta-LPH and ACTH. In patients, by contrast, cortisol levels were positively, albeit not significantly, related to age. Peptide levels were not related to age in the patient group. Instead, beta-ENDO/beta-LPH was negatively correlated with clinical ratings of symptom severity in patients and positively associated with an acute psychosocial precipitant. The findings cast further light on beta-ENDO/beta-LPH as a measure of hypothalamic-pituitary over activity in depressive illness. A negative association with symptom severity suggests that beta-ENDO/beta-LPH responses are, like those of ACTH, down-regulated in the course of depressive illness.