Changes of sleep architecture, spectral composition of sleep EEG, the nocturnal secretion of cortisol, ACTH, GH, prolactin, melatonin, ghrelin, and leptin, and the DEX-CRH test in depressed patients during treatment with mirtazapine

The noradrenergic and specific serotoninergic antidepressant mirtazapine improves sleep, modulates hormone secretion including blunting of hypothalamic - pituitary - adrenocortical (HPA) activity, and may prompt increased appetite and weight gain. The simultaneous investigation of sleep electroencephalogram ( EEG) and hormone secretion during antidepressive treatment helps to further elucidate these effects. We examined sleep EEG ( for later conventional and quantitative analyses) and the nocturnal concentrations of cortisol, adrenocorticotropin ( ACTH), growth hormone (GH), prolactin, melatonin and the key factors of energy balance, ghrelin, and leptin before and after 28 days of treatment of depressed patients ( seven women, three men, mean age 39.9 +/- 4.2 years) with mirtazapine. In addition, a sleep EEG was recorded at day 2 and the dexamethasone - corticotropin-releasing hormone (DEX-CRH) test was performed to assess HPA activity at days - 3 and 26. Psychometry and mirtazapine plasma concentrations were measured weekly. Already at day 2, sleep continuity was improved. This effect persisted at day 28, when slow-wave sleep, low-delta, theta and alpha activity, leptin and ( 0300 - 0700) melatonin increased, and cortisol and ghrelin decreased. ACTH and prolactin remained unchanged. The first two specimens of GH collected after the start of quantitative EEG analysis were reduced at day 28. The DEX-CRH test showed, at day 26, a blunting of the overshoot of ACTH and cortisol found at day -3. The Hamilton Depression score decreased from 32.1 +/- 7.3 to 15.5 +/- 6.7 between days - 1 and 28. A weight gain of approximately 3 kg was observed. This unique profile of changes is compatible with the action of mirtazapine at 5-HT-2 receptors, at presynaptic adrenergic alpha 2 receptors, at the HPA system, and on ghrelin and leptin.