How do you see your ideal daily routine?Most people on the planet would probably say they like getting up in the morning and going to bed before midnight. In general, the surrounding world is not without reason imprisoned for "larks", because they get up early, everyone has time and feel great. The rest of humanity is looking at this holiday of life with a cup of coffee in hand, hiding yawns and traces of lack of sleep. The fact that "owls" often sacrifice their own health for the sake of study or work, today is generally known, but still does not affect the beginning of a work or school day. Scientists from the University of Utah (USA), meanwhile, have found out why 3% of the Earth's inhabitants sleep at all until lunchtime, lying down with the first rays of the Sun. Such a special daily routine, as it turned out, arises from several genetic mutations at once and is called delayed sleep phase syndrome (SPSS). People with SPPS have difficulty waking up early and may take hours to fall asleep.
What is a chronotype?
Since the world around us is not black and white, there ismany chronotypes - individual characteristics of the daily rhythms of the human body and other animals. It is the circadian or circadian rhythms that are responsible for sleep, wakefulness, hormone production, body temperature, heart rate, blood pressure, and many other factors. It is interesting that all living organisms on Earth have this built-in biological clock.
It is believed that the chronotype reflects the daily dynamics of the functional activity of different organs and systems of the body, and depending on the activity of a person in the morning, day and night, they are isolated three main chronotypes: morning type (larks), day type (pigeons) and evening type (owls). However, the results of recent scientific studies show that there may be many more genetic variants of the chronotype.
Note also that the differences between the chronotypes -it is not just a tendency to wake up early or late. Each chronotype is characterized by individual characteristics of life, due to which it develops resistance to some factors and pronounced sensitivity to others... It is for this reason that larks get up no lightdawn, and the owls go to bed after midnight. But what happens to those of us whose daily rhythm does not fit into the standard 24 hours, moving several hours every day?
What is delayed sleep phase syndrome?
Scientists today with delayed sleep phase syndromeis a disorder in which a person's sleep comes with a delay of two hours or more (compared to most healthy people). For example, a person with SPSS may fall asleep at 2 a.m. instead of 10 p.m., which makes getting up early to school or work a real test of strength.
SPSPS, as noted by the researchers, is a rarea kind of evening chronotype. According to Robert Auger, a specialist at the Center for Sleep Medicine at the Mayo Clinic (USA), delayed sleep syndrome becomes a disorder when the schedule of school or work is not compatible with the time of going to bed. For example, when you need to be at work by 8:30 in the morning, and you fell asleep around 3 in the morning.
It is also important to note the difference between the SPSS and the normal evening chronotype: people with SPSPS have a hard time adjusting their internal clocks.
In fact we all lie down from time to timesleep an hour later than usual or so, and usually does not cause any problems with sleep. But you can suspect the presence of delayed sleep phase syndrome if your sleep is delayed by two to four hours every day. Experts also note that SPSPS usually accompanies insomnia - even if you turn off the light at 10 o'clock in the evening,the internal clocks in people with the syndrome will prevent them from falling asleep. As a result, they have difficulty waking up at certain times in the morning, and during the day they are overcome by excessive sleepiness.
Among other things, people with SPPS may havedepressive symptoms such as inability to concentrate and decreased productivity during the day. You can learn more about what depression is and why it must be treated in this article.
See also: What are circadian rhythms? Setting up your internal clock
What causes delayed sleep phase syndrome?
The exact cause of the disorder is not fully known.The researchers believe that SPSP is most likely to occur when the internal clocks that regulate sleep and wakefulness are weakened or inadequate for a desired sleep period. Lack of morning sunlight and overexposure to bright artificial light before bed play a role.
Genetics is also involved in the failure of the circadian rhythm towards the delayed sleep phase: as a rule, the delayed sleep phase syndrome is observed in families - approximately 40% of people inherited SPSPS from their parents, and according to the results of 2017,published in the journal Cell, a mutation in the CRY1 gene is common in people with SPSS. The CRY1 gene (cryptochrome circadian regulator 1) is responsible, you guessed it, for regulating circadian rhythms and plays an important role in the regulation of other physiological functions (metabolism, body temperature, blood pressure, and cardiovascular function). Thus, the nature of the development of the syndrome can be both congenital and acquired.
For even more fascinating articles on how sleep affects health and mood, read our channel in Yandex.Zen. There are regularly published articles that are not on the site!
Note also that disruption of circadian rhythms canbe triggered by certain medical conditions, such as depression, anxiety disorder, attention deficit hyperactivity disorder (ADHD), and obsessive-compulsive disorder. Chronic insomnia also leads to the development of SPSP in 10% of cases. Diagnosis of SPPS can be based on symptom descriptions and sleep tracking diaries.
Symptoms of delayed sleep phase syndromethe researchers attribute the inability to fall asleep at the right time (manifested in the form of complaints of insomnia), the inability to wake up at the right time, and excessive daytime sleepiness. Interestingly, people with SPSS sleep well, with little or no awakenings.