How Important Is Maintaining A Daily Rhythm For Mental Health?

By Beth Leipholtz 05/17/18

A new study examined the link between circadian rhythm disruptions and mental disorders.

woman fast asleep in bed

A good night’s sleep could now be more important than ever. 

CNN reports that a recent study determined that consistent circadian rhythms—which are daily sleep and wake cycles—are linked to mood improvements and cognitive functioning improvements, as well as a reduced likelihood of major depression or bipolar disorder. 

The research was published in The Lancet Psychiatry and studied disruptions in the circadian rhythms of more than 91,000 adults ages 37 to 73 in the United Kingdom.

Those disruptions were measured on accelerometers, which are devices worn on the wrist to track daily activity. 

Circadian rhythm disruptions were defined as increased activity at night, decreased activity during the day, or both. Researchers determined that those with more circadian rhythm disruptions were more likely to have symptoms linked to bipolar disorder or depression.

Researchers also determined that they were more likely to have decreased cognitive functioning and lesser feelings of well-being.

Dr. Daniel Smith, a leading author on the study and professor of psychiatry at the University of Glasgow, says daily activity is as important as good sleep.

"It's widely known that a good night's sleep is a good thing for well-being and health. That's not a big surprise," he said. "But I think what's less well-known and what comes out of this work is that not only is a good night's sleep important, but having a regular rhythm of being active in daylight and inactive in darkness over time is important for mental well-being."

For those involved in the study, activity levels were measured over a week-long period in 2013 or 2014. Mood and cognitive functioning effects were measured by participants filling out online questionnaires in 2016 or 2017.

Controlling factors like age, sex, lifestyle, education level and body mass index did not affect the consistency of the findings.

"I think one of the striking things that we found was just the consistency in the direction of our association across everything we looked at in terms of mental health," Smith said.

Aiden Doherty, a senior research fellow at the University of Oxford, was not involved in this study but says it is the first to utilize “objective measurements of daily activity” and that it is also the largest study of its kind.

"Previous studies have been very small (in just a few hundred people), or relied on self-report measures (asking people what they think they do),” Doherty wrote in an email to CNN. “However, this study used objective device-based measures in over 90,000 participants; and then linked this information to standard measures of mood disorders, subjective well-being, and cognitive function.”

The findings of this study could be particularly important for those who live in cities and have disrupted circadian rhythms, Smith notes. 

"By 2030, two-thirds of the world's population will be living in cities, and we know that living in an urban environment can be pretty toxic to your circadian system because of all the artificial light that you're exposed to," Smith said. "So we need to think about ways to help people tune in to their natural rhythms of activity and sleeping more effectively. Hopefully, that will protect a lot of people from mood disorders."

While researchers could not determine if rhythm disruption caused mental health issues or if it was the other way around, they say this research is still a step in the right direction. 

"It's an exciting time for this kind of research because it's beginning to have some real-world applications," Smith said. "And from my point of view as a psychiatrist, I think it's probably under-recognized in psychiatry how important healthy circadian function is, but it's an area that we're trying to develop."

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Beth is a Minnesota girl who got sober at age 20. By day she is a website designer, and in her spare time she enjoys writing about recovery at, doing graphic design and spending time with her boyfriend and three dogs. Find Beth on LinkedInInstagram and Twitter.