Melatonin, Sleep, and Depression
Melatonin, the hormone produced by the pineal gland, has been the matter of unsubstantiated, exaggerated claims during current years.
A veritable melatonin mania in the media and injudicious advertising has clouded the actual extraordinary role this hormone is known to play. On the other hand, there is an entire area of research related to its antioxidant, free radical scavenging properties.
Some, but not all researches of melatonin functions in major depression show low nocturnal secretion. Some, but not all SAD patients have a held up melatonin phase, where as lots of patients with non-seasonal depression have an earlier phase.
Some, but not all anti depression medicines improve melatonin levels. The dosage for managing melatonin depression for patients is therefore rather not clear.
Changes in sleep, but not in mood have been seen; melatonin may be beneficial as a secondary treatment for depression if rhythm abnormalities are actually present. Two researches have analyzed melatonin depression management in SAD patients, nevertheless, with no anti-depressant influences in spite of timing of ingestion to draw out a phase advance.
In another research, melatonin lowered startle and arousal responsiveness, as might be anticipated from its soporific properties, but there was no direct emotion accenting effect. Even though not yet actually investigated (but already successfully used clinically), evening melatonin incorporated with morning light appears to strengthen and accelerate circadian rhythm phase advances, thereby, enhancing and expediting the anti depressant effect.
Alterations in melatonin generation show disease states as both systems play a vital role in the management of melatonin secretion.
Unluckily, no constant changes in melatonin discharge have been found that reflect depression. For that reason, melatonin levels cannot be utilized to diagnose depression, and cure for melatonin depression is not appropriate.
Seasonal affective disorder, which is featured by repeating episodes of depression, augmented appetite in the winter and autumn, hypersomnia, meets the criterion of a rhythm disorder.
These people report a change in core temperature rhythms, but melatonin amplitude and rhythm seem to be inter changeable. The suggested treatment is timed exposure of bright light, and it is not certain whether melatonin management might helpful to this group of patients.
Melatonin discharge doesn´t look to be changed in women with premenstrual syndrome. People suffering from anorexia nervosa might have hiked melatonin blood levels, but this has no clinical implications.
Dosage of 3 mg melatonin at bed time to pre-menopausal and post menopausal women has been shown to increase thyroid function, causes an alteration of gonadotropins toward more juvenile levels, and might have some anti depressive activity. Use of melatonin alone for the relief of menopausal symptoms, including hot flushes, does not seem to be effective.
In very high pharmacologic doses, melatonin works as an antioxidant, possibly through non-receptor meditated mechanisms. It has been claimed that this property of melatonin supplements might have a preventive effect on illnesses affected by free radicals.
This antioxidant effect requires melatonin concentrations approximately 100 times greater than the physiologic melatonin secretion. Therefore, an antioxidant effect of melatonin may have some therapeutic application, but definitely not to the extent claimed in self help books.