Mental Health, Sleep, and Circadian Rhythms

Sleep: Most of us spend about a third of our lives there, but many of us struggle to get into it, get out of it, and even define it. As the US National Institutes of Health says, “Everyone needs sleep, but its biological purpose remains a mystery.” The details are vast and complicated, and we are just beginning to understand them. However, what we understand has broad implications for all of us, and perhaps especially for people with mental health problems.

Why circadian rhythms fascinate me

Cardiac rhtyms are patterns of behavior and physiology of approximately 24 hours, which are displayed by almost all cells in all life forms. They affect everything from mood to body temperature, blood pressure and growth. hormone to, yes, sleep. Circadian rhythms are created by molecular “clocks”, which synchronize our internal time with what is happening around us.

Since our circadian system regulates almost everything in our body, its disruption has important consequences in our physical and mental health. The complex molecular and genetic world that comprises the circadian system remains a frontier of exploration in neuroscience. We’ve made great progress in learning how genes influence our biological clock, but how that affects sleep, and how it affects and is affected by our mental health is much more complicated and difficult to unravel. The opportunity to investigate some of these mysteries is what drew me to this area of ​​research, especially as the potential to help people is so great.

What is sleep?

Sleep is a behavioral state that is scientifically defined in terms of slower waves in brain activity. However, it is a complex behavior that involves multiple biochemical and neural circuits working together in ways that we do not yet fully understand.

There are many general terms that we often use casually in general conversation that actually scientifically refer to a complex set of things. Autism, for example, used to be used as if it were a condition, when we now see it as a spectrum disorder. In decades past, we talked about finding “a” cure for cancer, as if cancer were just a disease with a single cause, when we now know that it is sadly much more complicated. The idea of ​​sleep is a bit similar. When you’re asleep, you haven’t simply switched off: one part of your brain is inactive, but other parts are (indeed, should be) active.

What happens when we disrupt circadian rhythms

In modern society, our circadian rhythms can be disrupted frequently. Whether you’re working on a factory line overnight or piloting a red-eyed transatlantic flight, nursing a baby, or just having a cup of coffee with breakfast, our bodies are often forced to ignore the information that comes our way. says when to rest and when. to be alert. Of course, many of these actions have mild effects.

But some people deal with a more extensive dysregulation of their circadian rhythms out of their control, with sleep disorders that create a mismatch between their sleep-wake pattern and the natural cycle of day and night. One example is delayed sleep phase disorder, in which people’s circadian rhythm shifts later at night and later in the morning, making it difficult for them to fall asleep and wake up at “normal” times. Such deep disruptions can be extremely problematic: Studies have shown that the body’s inability to synchronize the sleep-wake cycle with its environment can lead to cognitive decline, metabolic syndrome, and mental illness. Even this knowledge is surprisingly new.

The unmet medical need for sleep disruption

Currently, circadian rhythm disruption and sleep disruption do not have good treatments. There are melatonin and melatonin agonists, but while melatonin is an excellent biomarker of change (it’s a result of our biological clock, and monitoring it can help us track changes in our circadian rhythms), it’s not terribly effective as a treatment for most people. .

And there are sedatives and hypnotics, but those don’t provide the full restorative effects of natural sleep. If we can genetically understand circadian rhythms, we can begin to understand the pathways they use, and thus the pathways that new treatments might use. And this, perhaps, brings us closer to understanding the complex world of sleep.

Circadian rhythms and mental health: cause? Effect? Both?

Circadian rhythm dysregulation and accompanying abnormal sleep were once thought to be just a side effect of mental illness. They often co-occur, especially in conditions such as depression, Bipolar disorderand schizophrenia. It was often thought that perhaps a person’s mental health medicine caused sleep deprivation or perhaps your distress led to interrupted sleep. Certainly those things can happen.

However, we are increasingly investigating the opposite: the extent to which circadian rhythm disruption might be the cause, not the result, of some cases of mental illness. And there’s also a third possibility: mental health conditions and sleep problems can, in some cases, be caused by the same trigger. All three possibilities, or combinations of those possibilities, share the same hope: the better we learn how to help improve sleep, the more we can help improve, or even eliminate, co-occurring mental health conditions.

Maintain healthy circadian rhythms

Our circadian rhythms are regulated by many things: by light, by time, even by temperature. You’ve probably heard advice on how to minimize your evening. screen time and get natural sunlight during the day, especially early, whether you’re crossing time zones or just hoping to be as alert as possible during the day. You’ve probably also heard advice about good sleep hygiene, keeping your bedroom dark, cool, and quiet. All of that is true and backed by science! We may not have unraveled all the mysteries of sleep yet, but we have been able to determine many evidence-based ways to help people keep their circadian rhythms as healthy as possible.

However, many people with neuropsychiatric conditions are learning that their circadian rhythm abnormalities have deeper causes, sometimes genetic. My work, and that of my colleagues, follows this line. We are investigating the mechanisms that link circadian rhythms and sleep with mental health conditions and genetics of circadian rhythms in sleep and mental health.

For example, we now know that there are circadian and clock-controlled gene mutations that play a role in the development of sleep, mental health, and metabolic disorders. We hope that our work will help us understand how these complex processes work, how they work together, and how we can better understand them and develop effective treatments that can solve, or even prevent, these distressing problems.

Professor Aarti Jagannath is Associate Professor at the University of Oxford Sleep and Circadian Neuroscience Institute, as well as Academic Co-Founder of Circadian Therapeutics. His group investigates the fundamental neuroscience and molecular biology that underpin sleep and circadian rhythms, in particular, the mechanisms that regulate the circadian clock. drag. As well as being a scientific researcher, Professor Jagannath is an entrepreneur, educator, and advocate for women in STEM. She has fellowships from both the L’Oreal-UNESCO For Women in Science program and the Biotechnology and Biological Sciences Research Council.