A comprehensive new genetic study published May 26 in the journal JAMA Psychiatry suggests that Waking up just one hour earlier could reduce the risk of major depression by 23%. 

Sometimes, it’s challenging to get out of bed, particularly if a person is suffering from the fog of depression; the daily task can seem tiresome and purposeless. Moving through routines is difficult. Depression affects not only people’s feeling but also their motivations but a study affirms that waking up early helps in depression.

A study conducted on 840,000 people by researchers at the University of Colorado Boulder and the Broad Institute of MIT and Harvard provides substantial evidence that chronotype (a person’s inclination to sleep at a particular time) influences depression risk. It’s one among the first studies to quantify precisely how much, or minor, change in waking up early helps in depression.

As now the lockdown is getting easy in various parts of the world, people emerge, post-pandemic, from working or attending schools remotely — a trend that has led many to shift to a later sleep schedule has to change, and it could have significant implications.

“We have known for some time that there is a relationship between sleep timing and mood, but a question we often hear from clinicians is: How much earlier do we need to shift people to see a benefit?” said senior author Celine Vetter, assistant professor of integrative physiology at C.U. Boulder. “We found that even one-hour earlier sleep timing is associated with significantly lower risk of depression.” The statement supports the research implications that waking early can help in depression management.

Previous observational studies have shown that people stay up late, likely to suffer as much as twice from depression as early risers, irrespective of how long they sleep. But because mood disorders can also disrupt sleep patterns, researchers have had a hard time understanding what causes what.

What Does it Mean to be an Early Riser?

Some other studies but of sample sizes relied on questionnaires from a single time point or didn’t account for environmental factors that can influence sleep timing and mood, potentially surprising results. In 2018, Vetter published a comprehensive, long term study of 32,000 nurses showing that “early risers” were up to 27% less likely to develop depression over four years, but that raises the question of what is meant to be an early riser?

To get a more evident answer of whether changing sleep time earlier is shielding from depression and how much change is required, lead author Iyas Daghlas, M.D., referred to data from the DNA testing company 23 and Me the biomedical database U.K. Biobank. Daghlas then used a “Mendelian randomisation” method that leverages genetic associations to help reveal the cause and effect.

“Our genetics are set at birth, so some of the biases which affect other kinds of epidemiological research tend not to affect genetic studies,” said Daghlas, a graduate from Harvard Medical School. More than 340 genetic variants, also including variants in the so-called “clock gene” PER2, are known to affect a person’s sleeping patterns, and genetics collectively explains 12-42% of our sleep timing choices.

The researchers assessed de-identified genetic data on such gene variants from up to 850,000 individuals, including data from those 85,000 wearing sleep trackers for seven days and 250,000 who had filled out sleep-preference questionnaires. It gave them a granular picture of how these gene variants influence our sleeping routine.

In these samples, about a third of surveyed subjects self-identified as morning birds, 9% were night owls, and the rest were, on average, away from these extremities. Overall, the average sleep mid-point (halfway between bedtime and wake time) was 3 a.m., which means they went to bed at 11 p.m. and got up at 6 a.m. Using this data, the researchers turned to a different sample that included genetic data and anonymised medical and prescription records and surveys regarding diagnoses of major depressive disorder.

Using some novel statistical techniques, they asked: Do those with genetic variants predispose them to early also have a decreased risk of depression?

The answer is a yes.

Each one-hour earlier sleep midpoint corresponded with a 23% lower risk of major depressive disorder. This suggests that if someone who usually goes to bed at 1 a.m. goes to bed at midnight instead and sleeps the same duration as he used to do, it could cut the risk by 23%; if they go to bed at 11 p.m., it could cut the risk about 40%. However, it’s unclear from the study whether those who are already early risers could benefit from getting up even more early. But shifting to an earlier bedtime would likely be helpful for the intermediate-range sleepers or those who fall in the evening range.

Summary:

Going to bed one hour early than your usual routine can help to reduce the risk of depression.

What could Explain this Effect that Waking Up Early Helps in Depression?

Well, it can be attributed to some research that suggests that having greater light exposure during the day hours, which early-risers tend to get, results in releasing hormones that impact and can influence mood lifting.

Other research implies that having a biological clock, or circadian rhythm, that trends differently in different people can in itself be depressing.

According to Daghlas.” We live in a society that is designed for morning people, and evening people often feel as if they are in a constant state of misalignment with that societal clock”. He emphasises that a large randomised clinical trial is necessary to determine whether going to bed early can reduce depression. 

For those aspiring to drive themselves to an earlier sleep schedule, Vetter offers this tip:

She says, “Keep your days bright and your nights dark”. “Have your morning coffee on the porch. Walk or ride a bike to work if you can, and dim those electronics in the evening.”

Source:

Materials provided by the University of Colorado at Boulder.  Note: The Health Square team may edit content for style and length.

Journal Reference:

1. Iyas Daghlas, Jacqueline M. Lane, Richa Saxena, Céline Vetter. Genetically Proxied Diurnal Preference, Sleep Timing, and Risk of Major Depressive Disorder. JAMA Psychiatry, 2021; DOI: 10.1001/jamapsychiatry.2021.0959