The delayed sleep phase syndrome

The delayed sleep phase syndrome

Have you ever wondered what happens to people who can't fall asleep late into the night? They may be suffering from delayed sleep phase syndrome. Find out more in this article.

The delayed sleep phase syndrome

Last update: February 18, 2022

People with delayed sleep phase syndrome are unable to adjust to socially set times of sleep and wakefulness. Due to general misinformation and little understanding of this disorder, they are often labeled as lazy or listless by others.

The sleep-wake pattern follows a circadian rhythm, meaning it fluctuates regularly every 24 hours. This oscillation is determined by the internal biological clock which is also regulated thanks to certain external synchronizers. Social aspects such as working hours or meals serve to regulate more or less precisely the hours of sleep and wakefulness. The most powerful external synchronizer is given by the light-dark cycle.

The problem arises when there is a mismatch between the body's circadian system and the needs of the context in which one lives. In the case of delayed sleep phase syndrome, the person's usual nighttime sleep period is delayed compared to the conventional schedule.

Individuals who suffer from it they feel the need to go to bed and get up (chronically) at least two hours later than normal. This phase shift is more common in adolescence but often affects adults as well.

When daily commitments force the person to follow a common schedule, he will suffer from chronic sleep deprivation: he is unable to fall asleep at the desired time. All of this results in drowsiness and fatigue during the day, which will affect their academic or work performance.

During holidays or holidays, when possible freely delay the time of sleep, this returns to normal both in terms of quantity and quality. Insomnia and the difficulty in waking up disappear and the person is able to enjoy a good, restorative sleep.

Differential features of delayed sleep phase syndrome

Some of the common traits in delayed sleep phase syndrome are:

  • The person maintains adequate sleep hygiene, but still cannot sleep at the desired time.
  • There are no personal or work situations, symptoms of anxiety or depression that justify the person's lack of sleep.
  • After falling asleep, those suffering from this syndrome have no difficulty in maintaining it; sleeps continuously and does not wake up suddenly like those suffering from maintenance insomnia.
  • Due to lack of sleep, sleepiness and alertness increase during the first half of the day. This situation improves as we approach the maximum waking point, which tends to be early evening in these people.
  • When the person can choose the time to go to bed, the person sleeps without difficulty and wakes up rested.

Treatment of delayed sleep phase syndrome

Behavioral intervention

The first step is to intervene on the behavior of the individual, trying to improve sleep hygiene as much as possible. Check the context in which he sleeps, the consumption of stimulants or the type of activity he does before going to sleep.

In this sense, it is particularly important that the person acquires fixed times for going to bed and waking up. It is essential that you follow them day by day without changing them on holidays or holidays. The habit must be maintained even when the goal is reached, in order to avoid relapses.


Reducing exposure to light at sunset and increasing it in the morning can help boost the biological clock. This is why it is important to use a soft light during the last hours of the day and to avoid the light of the screens.

On the other hand, it is good sleep with the blinds up to increase light exposure solar in the minutes before waking up.


The administration of melatonin (1-5 mg) a few hours before going to sleep helps advance the sleep-wake cycle. In combination with phototherapy it increases in effectiveness.


This procedure consists of slowly delaying the time of going to bed and getting up. The person will go to sleep later each night until the desired sleep time is reached. From that moment on, the challenge is to keep it.

The main difficulty lies in the fact that it will take several days to change your sleep schedule until you reach the ideal one, and this could interfere with work or school responsibilities. In any case, there are methods and strategies to prevent this alteration from becoming a limit for the person.

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