24-Hour Profiles of Adrenocorticotropin, Cortisol, and Growth Hormone in Major Depressive Illness: Effect of Antidepressant Treatment*

TLDR

The study measured plasma ACTH, cortisol, and GH every 15 minutes over 24 h in 11 men with major depressive illness during an acute episode and after remission following electroconvulsive therapy or amitriptyline, and in 7 age‑matched healthy controls. Acute depression was associated with hypercortisolism, early ACTH‑cortisol nadirs, shortened REM latency, nocturnal cortisol quiescence, and wake‑time GH hypersecretion, all of which normalized after treatment, indicating that circadian rhythm disturbances and hormone hypersecretion are state‑dependent features of major depressive illness.

Abstract

Plasma ACTH, cortisol, and GH concentrations were measured at 15-min intervals for 24 h in 11 men suffering from major depressive illness during an acute episode of depression and during clinical remission following antidepressant treatment with either electroconvulsive therapy or amitriptyline. Seven age-matched normal men also were studied. During the acute phase of the illness, the patients had abnormally short rapid eye movement sleep latencies, hypercortisolism, early timing of the nadirs of the ACTH-cortisol rhythms, and snorter nocturnal periods of quiescent cortisol secretion. GH was hypersecreted during wakefulness, and a major pulse occurred before, rather than after, sleep onset. After treatment, rapid eye movement sleep latencies were lengthened, and cortisol levels returned to normal due to a decrease in the magnitude of episodic pulses. Moreover, the timing of the circadian rhythms of ACTH and cortisol as well as the duration of the quiescent period of cortisol secretion were normalized. The amount of GH secreted during wakefulness decreased to normal values, with fewer significant GH pulses. The major elevation of GH secretion in the early part of the night occurred later than that during the depressive episode. These results demonstrate that a disorder of circadian rhythmicity characterizes acute episodes of major depressive illness and that this chronobiological abnormality as well as the hypersecretion of ACTH, cortisol, and GH are state rather than trait dependent.