If you like to skip on sleep, we have some bad news: a new study reports that people whose sleeping patterns go against their natural body clock are more likely to be depressed, and experience lower levels of wellbeing.
Early bird gets the worm and all that, but we now have evidence to show that some people really are naturally early risers. Even worse, going against this, or being a night owl by nature, seems to promote issues such as depression and lower perceived quality of life. But you can rest easy, there's nothing wrong with you. Most likely, these effects are caused by the way our societies are ordered, as they are generally tailored more for early risers, through the standard 9-5 working pattern.
The right time for sleep
The research was built on previous work that mapped 351 genes linked to being either an early riser or a night owl. A statistical process known as Mendelian Randomisation was employed to see whether these genes had a causal association with seven mental health and wellbeing outcomes (major depression was one of these seven). Data for the study was supplied from the UK Biobank's biomedical database and research resource and pertained to over 450,000 UK adults.
Apart from genetic information, participants also supplied information regarding their sleeping habits (i.e. whether they were a morning or evening person) through a questionnaire.
Alongside this data, the authors also developed a new indicator of "social jetlag", a measurement of the variations in sleeping patterns one experiences between workdays and free days. This was measured in around 85,000 UK Biobank participants (for whom sleep data was available) via wrist-worn activity monitors.
The first important finding of the study was that participants whose natural and actual sleeping patterns were more misaligned were more likely to report depression, anxiety, and lower wellbeing.
"We found that people who were misaligned from their natural body clock were more likely to report depression, anxiety, and have lower wellbeing. We also found the most robust evidence yet that being a morning person is protective of depression and improves wellbeing," says lead author Jessica O'Loughlin, of the University of Exeter.
"We think this could be explained by the fact that the demands of society mean night owls are more likely to defy their natural body clocks, by having to wake up early for work."
Morning people had the highest likelihood of their sleeping patterns being aligned with their natural body clock. When looking at shift workers alone, the team found that being a morning person doesn't seem to protect them from depression. This is likely indicative that morning people who work shifts don't get any benefits from their natural sleeping patterns, but this remained inconclusive overall.
"The COVID-19 pandemic has introduced a new flexibility in working patterns for many people. Our research indicates that aligning working schedules to an individual's natural body clock may improve mental health and wellbeing in night owls," said senior author Dr Jessica Tyrrell, of the University of Exeter.
The paper "Using Mendelian Randomization methods to understand whether diurnal preference is causally related to mental health" has been published in the journal Molecular Psychiatry.
