Delayed sleep phase syndrome (DSPS) is a common cause of insomnia in children and adolescents. Overall, 1 to 15 percent of patients with chronic insomnia suffer from a delayed sleep period. Approximately 8% of young people’s sleep problems are explained by a delayed sleep phase syndrome.
Patients are incapable of falling asleep at the desired time in the evening and often stay awake for many hours at nights. After falling asleep at 01–04, they usually sleep well. Students with severe symptoms have major problems at waking up in the morning. If they wake up, they are tired because of insufficient sleep.
Delayed sleep phase syndrome is associated with poor school performance, smoking, alcohol use, anxiety and depression. Disturbances in attention and impulse control and DSPS are strongly interrelated, and almost without exception a young ADHD person has a delayed sleep phase syndrome or at least he is clearly an evening person.
Problems with delayed sleep phase syndrome (DSPS)
The problem arises from the conflict with the social environment. If a person has to wake up early in the morning to go to lectures or work, he or she is tired and irritated because of the lack of sleep. Delaying the body’s internal clock can, for example, begin when the student studies for many consecutive nights, or when the journalist writes his stuff at night. If a journalist or researcher can sleep freely in the morning, no problem arises. But if he wants to change his rhythm, insomnia begins. At weekends, the problem is not the same, as the person can sleep longer on weekends than on working days.
A delayed sleep phase syndrome is a typical example of a circadian rhythm sleep disorder. The person can’t fall asleep until late at night, because the internal clock is behind several hours of the social clock. When the social clock is 23, the internal clock can tell the body that the clock would be 19 and the person is not yet tired.
The diagnosis of a delayed sleep phase syndrome is primarily based on interviews and keeping a sleep diary. Wrist actigraphy verifies diagnosis. Sometimes it is appropriate to exclude other causes of fatigue with a sleep study. It is also possible that the patient has not only a delayed sleep phase syndrome, but also, for example, restless legs and associated night-time limb movement. It is sometimes appropriate to conduct neuropsychological examinations to determine alertness and impulse control.
Treatment of delayed sleep phase syndrome
The delayed sleep phase syndrome is treated by trying to synchronize the internal clock. Theoretically, the easiest way would be to move the sleeping time until the biological clock and the social clock “shows” bedtime at the same desired time. However, this is very difficult in practice and is usually done differently. First, the need for a night’s sleep is solved, and at what time in the morning the person has to get out of the bed to go to school or work. In other words, how many hours a person should sleep to be rested the next day and at what time should he or she go to sleep at the latest.
Initially, the patient is kept awake until the small hours of the morning (for example, at 03 o’clock) so that the length of the night’s sleep is only about 4-5 hours. The next night, bedtime will be shifted 15 to 30 minutes earlier. In this way, awake time is reduced until the desired result is achieved.
Advanced sleep phase disorder (ASPD)
A delayed sleep phase syndrome (DSPS) is common. The opposite is advanced sleep phase disorder, which is clearly less common. In advanced sleep phase disorder, people start to get tired very early in the evening. Advanced sleep phase correlates with a strong morning type. As the age increases, people change more in proportion to a morning type.
A delayed or advanced sleep phase syndrome, which can be disruptive to social life, can be explained by abnormal activity of clock genes. It may also be a hereditary feature.
Melatonin helps in sleep-wake rhythm transmission
Previously, short-acting sleeping pills were temporarily used to assist in sleep-wake rhythm transmission, which were gradually discontinued within a few days after rhythm transmission.
Sometimes this practice is still used, but nowadays, melatonin in the evening and bright light given in the morning when waking up in the morning are used to facilitate rhythm transmission. In such cases, melatonin will always be taken at no later than 20-22 o’clock in the evening, depending on the difficulty of delaying the rhythm. So this should always be done even if you go to bed only at 23 o’clock or later.
Melatonin should never be taken after midnight. The best time to take melatonin can be determined very precisely by measuring DLMO (dim light melatonin onset) from the melatonin of saliva. Melatonin should generally be taken at least one hour and in some cases 5 hours before DLMO. The general rule for DLMO is 6 hours before midsleep. This midsleep is the midpoint of the time of falling asleep and the time of awakening.
Bright light therapy in the morning
For best results, bright light should be obtained before 10 am. The best time is right after awakening. One of the options is to use a bright light therapy lamp on the bedside table, the light of which will gradually brighten to mimic the rise of the sun in the morning.
In the afternoon and early evening, a bright blue-tinted light delays sleep rhythms. By getting bright light early in the morning, the internal clock can be moved forward.
There are several different types of bright light equipment on the market. The success of the treatment can be assured by a sleep diary, wrist-actigraph and, if necessary, by usage of melatonin. In successful treatment, the nocturnal excretion peak of melatonin can be transmitted several hours earlier.
Such a rhythm transmission may be successful at home, but sometimes it is advisable to take a course of treatment in a sleep disorder clinic.