What is Insomnia?

Insomnia is the difficulty in starting or maintaining sleep. This difficulty negatively affects daytime performance and is treated with cognitive-behavioural therapy, with or without sleep hypnotics.

What is Melatonin?

Melatonin is a neurohormone synthesized in the body and produced by our brain that is secreted only during the dark hours of the day-night cycle. This hormone is not stored but is released once produced, and is related to the process of sleep induction and internal synchronization of the circadian rhythm. Its regulation is carried out by the amount of light that reaches our retina in the eye.

The production of melatonin is influenced by factors such as age (more abundant in children), the season of the year (in summer the secretion of melatonin is advanced and in winter it is delayed), the menstrual cycle, stress or exercise, daily time of sun exposure, some drugs such as benzodiazepines or beta blockers (a type of antihypertensive drug) and even some pathologies (in liver cirrhosis the production of melatonin is decreased).

What are the properties of Melatonin?

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Today there is a growing interest in the use of this hormone in circadian rhythm disorders such as in jet lag (long flights), shift work changes (working night/day shifts), and in sleep disorders in the elderly.

It has been shown that the intake of melatonin improves the onset of sleep, as well as the continuity of it during the rest hours, also ensuring that waking up is without lethargy so that it does not interrupt our daily activities.

What is the Circadian Rhythm?

The Circadian Rhythms are internal periodic biological rhythms that manifest with a 24-hour interval. The most important is the wake-sleep cycle. In Circadian Rhythm Disorders, the amount and quality of sleep is normal, but it occurs at the wrong time according to usual schedules.

In various studies, it has been proven that volunteers who were deprived of sleep for four to five hours for a few days experienced alteration of neuro-cognitive, behavioural, metabolic parameters and vital functions, cardiovascular and immunity.

What are the sleep phases?

Sleep is characterized by two stages:

Slow sleep, orthodox or non-REM (REM: Rapid Eye Movement) which is determined by four phases, which follow one another and can fluctuate during the same night:

• Phase 1 – drowsiness. It is observed immediately after wakefulness and lasts a few minutes. The muscle tone is somewhat lower than during wakefulness, and eye movements are slow and appear intermittently.
• Phase 2 – "light" sleep. The brain activity of wakefulness decreases and light awakenings may occur.
• Phases 3 and 4 – deep slow sleep itself, where there is a continuous predominance of slow brain activity waves and that predominate in the middle of the night.

Paradoxical or activated or REM sleep, where there is a high activity of brain waves similar to those determined when awake, hence the rapid eye movement, and which does not imply awakenings, since there is a notable decrease or complete loss of muscle tone during which sharp muscle twitches also occur.

What is REM Sleep?

This stage of sleep accounts for 20% of our sleep cycle, meaning, it lasts between 15 and 30 minutes. Its name rapid eye movement is due to the constant movement of the eyeballs under the eyelids. This phase is characterized by having high brain activity, similar to what we have while awake, changes in breathing and heart rate, but the muscles are blocked. This is the phase in which we dream and can process the information accumulated during the day, likewise, if we are awakened just at this stage it is possible to remember what we were dreaming.