Waking up just an hour earlier can reduce a person’s risk of depression by 23%, finds a new genetic study published May 26 in the journal Neurology. JAMA Psychiatry.
A study of 840,000 people by researchers at the University of Colorado, Boulder, and the Broad Institute of MIT and Harvard shows some of the strongest evidence that chronotypes are synonymous with chronotypes. which is the tendency to sleep over a period of time. Affects the risk of depression
It is also one of the first studies to determine how much or how much change is needed to affect mental health.
when people show up after the epidemic from work and to school from a distance This is a trend that causes many people to switch to bedtime later. The findings could be significant.
“We have known for a while that there is a relationship between sleep time and mood. But the question we often hear from doctors is: How quickly do we have to switch people to see benefits?” said senior author Celine Vetter, an assistant professor of integrative physiology at CU Boulder. hours were also associated with a significantly lower risk of depression.”
Previous observational studies have shown that night owls are twice as likely to suffer from depression as early risers. no matter how long you sleep But because mood disorders can interfere with sleep patterns. So researchers had difficulty deciphering what was causing it.
Other studies had small sample sizes. based on questionnaires from a single period or regardless of environmental factors that can affect both sleep duration and mood This can confuse the results.
In 2018 Vetter published a large, longitudinal study of 32,000 nurses, showing that “Early people” were 27 percent less likely to experience depression over the past four years. But that begs the question, What does it mean to be a nurse waking up early?
Lead researcher Iyas Daghlas, MD turned to data from DNA testing companies 23 and Me and the biomedical database UK Biobank to better understand whether delayed sleep is actually preventable. Daghlas then used a method called “Mendelian randomization” that leveraged genetic links to help decipher cause and effect.
“Our genes are determined from birth. Therefore, some biases affect other types of epidemiological research. It doesn’t usually affect genetic studies,” said Daghlas, a May graduate of Harvard Medical School.
More than 340 common genetic variants, including a variant known as the “clock gene,” PER2, are known to influence a person’s chronology. And overall genetics account for 12-42% of our bedtime preferences.
The researchers assessed anonymized genetic information in these variants from up to 850,000 individuals, including data from 85,000 people who wore wearable sleep trackers for 7 days and 250,000 people who completed questionnaires. with sleep satisfaction This allows them to see a more detailed picture. Until the hour how variables in genes influence when we sleep and wake.
In the largest example About a third of the surveyed volunteers identified themselves as morning birds, 9% as night owls, and the remainder in the middle. Overall, the average mid-night bedtime was 3 a.m., meaning they went to bed at 11 p.m. . and get up at 6 a.m.
with this information The researchers therefore turned to a different sample that included genetic information along with anonymous medical records and prescriptions. and a survey on the diagnosis of major depressive disorder.
using innovative statistical techniques They asked: Are people with the genetic variant that predisposes to getting up early also have a lower risk of depression?
The answer is definitely yes.
The halfway point of sleep gets faster every hour. (Halfway between bedtime and waking time) was associated with a 23% lower risk of depression.
This suggests that if people who normally go to bed at 1am go to bed at midnight instead and go to bed at the same time. They were able to reduce the risk by 23%; If they go to bed at 11 p.m., they can be reduced by about 40%.
Studies are unclear whether early risers benefit from waking up earlier. but for those who are in the middle or in the evening Changing to bed earlier should help.
What could explain this effect?
Some research suggests that more exposure during the day. which those who wake up early often receive This results in hormonal effects that can affect mood.
Others have noticed that having a biological clock or circadian rhythm that tends to differ from what most people can do on their own is depressing.
“We live in a society designed for morning people. And evening people tend to feel as if they are in a state of constant dissonance with that social clock,” Daghlas said.
He stressed that larger randomized clinical trials are needed to determine whether going to bed early helps reduce symptoms of depression. “But this study shifts the weight of the evidence to support the causal effect of sleep on depression.”
For those who want to switch to bedtime faster, Vetter offers this advice:
“Keep your days bright and your nights dark,” she says. “Drink your morning coffee on the balcony, if you can, walk or bike to work. and dim those electronic devices in the evening.”