Early bird and night-owl are terms often used to describe our general sleep patterns, but if you want to understand the specifics of your sleep-wake cycle, look to your sleep chronotype. Beyond sleep, recent research suggests that sleep chronotypes may also influence a person’s risk of depression.
Which sleep chronotype is least likely to be depressed?
The study, published in the journal JAMA Psychiatry, analyzed the genetic data of 840,000 people and found those who are genetically predisposed to waking up earlier were less likely to be diagnosed with depression. According to the four chronotypes, that would mean anyone who identifies as a bear or a lion is at a lower risk of depression. (To find out which sleep chronotype you are, read here.)
If you happen to fall into the late-night category (looking at you, wolves and dolphins), don’t stress. The researchers also found that other chronotypes can lower their risk of depression by 23% just by waking up one hour earlier than normal. So, if you typically wake up at 9 a.m., shift your alarm to 8 a.m. instead—that subtle shift can make a big difference.
To better understand the impact of wake-time, lead author Iyas Daghlas, M.D., used DNA testing to look at more than 340 genetic variants that influence sleep chronotypes. After gathering this data, the researchers then looked at another sample of genetic information and medical records indicating major depressive disorder diagnoses.
Based on the findings, it was clear that people genetically predisposed to rising early were less likely to be diagnosed with depression. Though prior research has linked irregular sleep patterns to depression and found that night-owls are twice as likely to be depressed, this is the first study to determine exactly how much a person’s wake time should change in order to influence their mental health.
“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?” study author Celine Vetter, M.Sc, said in a news release. “We found that even one-hour earlier sleep timing is associated with significantly lower risk of depression.”
How does the morning affect mood?
Though it’s unclear why early risers are less likely to be depressed, some researchers suggest the extended natural light exposure can trigger feel-good hormones and, therefore, enhance mood.
Additionally, having a sleep pattern that differs from most other people’s (especially in the case of shift workers) can be difficult. “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,” Daghlas said.
While there are plenty of factors that might determine someone’s waking hours, aiming to rise at least one hour earlier may significantly benefit mood. To try to ease your way into becoming a morning person, “keep your days bright and your nights dark,” Vetter advises. “Have your morning coffee on the porch. Walk or ride your bike to work if you can, and dim those electronics in the evening.”