The researchers found a correlation between the violation of sleep and wake cycles and the presence of mental disorders on a large sample of Britons: more than 90 thousand people. The results of the work, published in The Lancet Psychiatry magazine , show that people who go to bed late fall asleep more often from bipolar disorder and depression, and also complain of loneliness and mental distress.
In modern people, due to artificial lighting, the biological clock (circadian rhythms regulating cycles of sleep and wakefulness with the help of chains of genes and proteins) is often confused. Violation of the “settings” of such clocks (besides the light, it can affect the need to work in the night shift and sleep during the day) has many negative consequences, for example, an increased risk of developing Alzheimer’s disease and multiple sclerosis .
Therefore, doctors and adherents of a healthy lifestyle recommend refraining from classes that can prevent a timely departure to bed in the evening: for example, ask not to use gadgets at bedtime. In support of the fairness of this council, the results of a study conducted by scientists from the University of Glasgow under the leadership of Laura Lyall (Laura Lyall) can also speak. In their experiment, data on the seven-day activity of people, taken with the help of wristbands, were used: in total, 91,105 participants of the UK Biobank project at the age of 37 to 73 years were monitored.
Based on the data from the bracelets, scientists calculated how much the sleep and wake cycle was disturbed: that is, how active the participant was at night. Another variable was the presence of participants in mental disorders, as well as their subjective assessment of their own mental well-being. Scientists also took into account information about the time of year when observations were made, the sex and race of participants, alcohol and tobacco consumption, socioeconomic status, overall activity (also measured with a bracelet), and body mass index and childhood injuries – as an indicator of probability development of mental disorders.
It turned out that among the more active at night people the risk of having bipolar disorder was 11 percent higher, and depression was higher by six percent. In addition, these participants also reported more often about loneliness, mental unhappiness and discontent with one’s own health.
Despite the fact that the sample of participants in the study is large enough, it is impossible to establish a causal relationship between activity at night and the mental state: late retirement can be both a cause and a consequence of mental disorders and general discontent with one’s own condition.
It is also worth noting that during the analysis, the researchers took into account the data on the daily activity of participants, which made it possible to exclude the possibility that the atypical regime will affect the establishment of interrelations: night work and daytime sleep.
In many ways, the excessive use of artificial lighting on human health is facilitated by the continued use of gadgets. They emit a bright blue light (this allows the screen to be visible even in the daytime), which is perceived by the human eye as a sharp white. When using gadgets at night, the body decides that light reaching the retina is in fact daylight: because of this, melatonin production slows down. In addition, sharp contrast lighting tires the eyes. And although the work is not a direct relationship was noted between the use of gadgets at night and the risk of mental illness, one of the authors of Daniel Smith (Daniel Smith) sure, that the fault of the failure of the biological clock is poor sleep hygiene, one of the indicators of which is the use of gadgets at night.
Gadgets – not the only source of artificial lighting, which can bring down the work of circadian rhythms and tire your eyes. In 2016, the American Medical Association, for example, released a report describing the health effects of light from LED street lamps.