Circadian rhythms and mental health in lockdown

NOW, well into its second year, the COVID-19 pandemic continues to threaten the mental and physical health of Australians.

The “lockdown” or “stay-at-home” strategy has emerged as one of several effective ways around the world to disrupt the spread of COVID-19 in our communities. But it is now clear that long periods of lockdown have negatively impacted our collective mental health, with one factor contributing to disrupting our established rhythms of life.

With the pandemic and lockdowns going on for a while, it’s time to talk about how our circadian rhythms and mental health can be affected, and to discuss practical strategies to keep our “physical clocks” during the pandemic and beyond keep healthy.

Circadian rhythms and health

We live on a planet that rotates on its own axis and makes a full revolution every 24 hours, creating our day and night. Millions, if not billions of years ago, evolutionary pressures favored organisms that developed a biological “clock,” a clock that tracked the daily rise and set of our sun.

By 2021, virtually every living organism will contain a network of biological clocks that run for approximately 24 hours, known as circadian rhythms or circadian clocks. For us mammals, the so-called master clock is located in a small bundle of cells at the base of our brain, the suprachiasmatic nucleus. Its main source of information about time is light.

We humans benefit immensely from our circadian system – it regulates the timing of practically all processes necessary for health and well-being, including sleep-wake rhythm, mood, energy, cognition, metabolism, digestion and immunity. For these reasons, the new field of circadian medicine is at the center of our understanding of health and disease.

Importantly, our circadian clocks, like man-made clocks, can come from time. Most of us are familiar with the experience of jet lag – a syndrome caused by the incorrect timing of our internal biological time and the external time of the local day and night cycle – caused by traveling quickly across time zones. Our circadian system can be disrupted by a number of other factors such as infections, inadequate exposure to light and irregular sleep-wake routines, leading to a constellation of psychological and physical phenomena such as fatigue, mood disorders, irritability and gastrointestinal problems, among others. In addition, circadian disorder is now recognized as a risk factor for a number of important health conditions, including stroke, cardiovascular disease, mood disorders, and dementia (here and here).

The “circa” in circadian means “approximately”. This reflects that our circadian system produces internal rhythms that last about 24 hours, but not exactly 24 hours. Like a clock that runs a little fast or a little slow, it has to be reset every day. The exposure to light – especially the morning sun – is the most important determinant for the regularity of our circadian rhythms (here and here). Other important but far less effective factors are the regularity of the sleep-wake cycle and the timing of physical activity and possibly social activity.

Crucially, each of these factors involved in regulating our circadian clocks were likely to have been affected during the pandemic and especially during the lockdown.

Circadian rhythms in pandemic and lockdown

Data during the COVID-19 pandemic are now available from many countries around the world reporting changes in behavioral and biological rhythms, as well as changes in factors critical to the healthy functioning of our circadian system.

First, several large survey-based studies have reported some positive changes in the sleep-wake cycle during lockdown periods (here and here).

For example, a survey of over 7,000 adults from 40 countries who had been exposed to social restrictions for one month (on average) due to COVID-19 reported an increase in sleep time on weekdays and a decrease in sleep time on weekends. In addition to these changes in sleep-wake timing, a reduction in “social jetlag”, which relates to the discrepancy between sleeping times on working days and non-working days, has been reported.

Similarly, a study of the approximate sleep time from a smartphone sleep tracking app of over 8,000 users in the US, UK and South Korea reported that the estimated sleep time was increased by 13 minutes and 22 minutes between March 2019 and March 2020, respectively estimated sleep duration between April 2019 and April 2020.

Taken together, these studies suggest that a large population-level sleep deficit that existed before the pandemic may be caused in some people by a loosening of the way we spend our social time (e.g. how we navigate our schedules if we are the Have the COVID-19 pandemic behind us.

Importantly, several studies also show negative changes during the pandemic and locks related to the circadian system.

For example, a survey of about 800 health care workers in the United States collected data on changes in a number of lifestyle factors (including work, sleep, screen time) and reported that after COVID-19 stay-at-home orders, people found themselves – reported mood deteriorated, physical activity decreased, and substance use and screen time increased. Compared to respondents who said their moods stayed the same or better during the pandemic, respondents whose mood worsened said they slept less after being ordered to stay at home and were less likely to postpone bedtime later were more likely to work from home and use screens more often before bed.

Similarly, a large survey of individuals in the United States and Australia reported significant disruptions in social life, family life, work and study, sleep, sexual activity, and physical activity, with more time spent on screens (possibly increased inappropriate nighttime light exposure). ) and fewer commuting times (presumably decreasing bright and regular daylight exposure).

Collectively, these studies show a number of lifestyle changes that suggest disruption of factors related to the circadian system (light, physical activity), some of which explain and important some of the changes in mood and mental health at the population level during the pandemic Areas for education and lifestyle change related to circadian health.

Some of these considerations are likely to be of great concern to certain groups of people who may be more sensitive to the effects of circadian disorders; for example people with mood disorders like depression or bipolar disorder (here and here). What is important is that we know a number of simple lifestyle changes that people can implement in their daily life to keep their sleep-wake cycle and circadian system working both during lockdown and beyond.

Lifestyle strategies for circadian health

exposure

Light is the most important signal that tells our circadian system what time it is. Circadian rhythms were developed to track and predict the 24-hour light-dark cycle. Bright light in the morning (ie sunlight) is extremely important in order to “reset” our internal clock every day. Conversely, light in the evening (from screens or electrical home lighting) can suppress the sleep-inducing hormone melatonin and delay our clocks, making it difficult to fall asleep and wake up rested. Rethinking our relationship with light can help our circadian clocks function in more natural and healthier ways.

People should try to maximize exposure to sunlight during the day, especially in the morning, for example by taking a morning walk outdoors or by sitting by the window after waking up. To reduce the negative effects of light on your circadian clocks, try eliminating screen time and other light sources 1–2 hours before bed – try swapping screen time to read a book or listen to music or a podcast hear. Note that our watches expect light days and dark nights. The closer you get to what your watch expects, the better your sleep and overall health will be.

Sleep-wake cycles

The time we go to sleep each night and wake up each day greatly affects the timing of our circadian clocks. It is important that we try to maintain a regular sleep-wake cycle and keep it up during the week and on weekends. You should follow the regular schedule that feels natural to you (and makes you feel good), even if it is a little different from others in your household.

Physical activity

Regular physical activity is believed to maintain a strong circadian clock. Try to exercise around the same time each day; Do not exercise too late in the evening, however, as this will increase core body temperature and make it difficult to fall asleep and wake up rested.

Social interaction

It’s more important than ever to keep in touch. While we may not now be able to meet up with friends and family in the usual way, try to schedule regular phone calls or exercise with family friends during the week, which can help regulate our circadian rhythms.

Meal times

We are learning more and more about how food affects our physical health. The timing of our meals affects the timing of the circadian clocks in organs such as the stomach and liver, and eating randomly throughout the day and too close to bed can negatively affect our metabolism and digestion. Try to eat at a regular time each day, and eat your last bite about 2 hours before bed.

In summary, the COVID-19 pandemic has forced us all to reconstruct our daily lives, but it has also given us an opportunity to reflect on our lifestyles and think about how we could live better. Learning and changing our relationships with our circadian clocks is one way to improve all aspects of our health and wellbeing.

Jacob Crouse is a research fellow at the Brain and Mind Center at the University of Sydney. His work examines the connections between circadian rhythms and mood disorders in young people.

Joanne Carpenter is a research fellow at the Brain and Mind Center at the University of Sydney. Her work focuses on biological circadian rhythms and mental health in young people.

Sean Cain is an Associate Professor at Monash University and currently the President of the Australasian Chronobiology Society. His work focuses on how light affects sleep and mental health.

Ian Hickie is Co-Director (Health and Policy) and Professor at the Brain and Mind Center at the University of Sydney. His work focuses on developing personalized and measurement-based real-time care systems for the mental health of young people.

Statements or opinions expressed in this article reflect the views of the authors and do not constitute the official policies of the AMA, MJA, or InSight +, unless otherwise stated.

source https://www.bisayanews.com/2021/10/03/circadian-rhythms-and-mental-health-in-lockdown/