It’s often said that no-one really knows what sleep is for. Sometimes it’s as if this lack of surety means its functions are relatively unimportant or even vestigial, like an appendix to the story of our life. How we evaluate life has long since focused on the daytime – what we think and feel when we’re awake. But given that the quality of our wakefulness is fundamentally influenced by what happens when we sleep, maybe that focus has been misplaced.
In recent years, science has yielded startling insight into the nature and functions of normal sleep and of our circadian rhythm or body clock. For example, we now know that sleep allows the brain to reset, helping to integrate newly learned material with already consolidated memories; that sufficient sleep may be as protective to your heart as not smoking, and that early risers are better protected from depressive disorders.
Sleep, like oxygen, water and food, is one of life’s essentials and is a primary determinant of health and well-being. Poor sleep has been shown to significantly increase the risk of health issues from anxiety and depression through to cardiovascular disease, stroke and diabetes as well as suppressing the immune system and so leading to higher levels of infection.
This is just the start of our discoveries about sleep. The fact that sleep is universal across all species, tightly regulated, and cannot be lost without serious harm, implies that sleep has important core functions. There is so much more to it than we currently know.
Into the Unknown
One of the most prevalent mental factors associated with insomnia is the “racing mind”. That’s why Cognitive Behavioural Therapy (CBT) is such an effective solution. It addresses this as well as helping sufferers overcome the worry and other negative emotions that accompany the experience of being unable to sleep.
But the racing mind is not all in your head. There is good research evidence that people with insomnia have brains that are more active during sleep than is found among good sleepers. Studies which use quantitative measures of the sleep EEG (electrical brain activity) show greater levels of high frequency wave-forms; ones that are more typical of wakefulness, even when people with insomnia are asleep.
Future research will investigate this phenomenon using EEG and also using brain scanning technology, and could well help to unlock the mystery of insomnia. It will also be of interest to see if CBT has an impact upon this underlying brain activity as well as upon thought processes.
Real Life, Real Time Research
Finding out about sleep is not just limited to the lab. Because of its importance to everyday life, it’s vital to understand how our sleep affects us in the real world. To do that, we need to understand how people are sleeping, not just what’s affecting their sleep but also how their sleep is affecting them and their well-being. That’s why we developed the World Sleep Survey, which aims to be the largest ever survey of the world’s sleep.
Based on the latest scientific research, the survey looks at our schedule, lifestyle, thoughts and emotions, health and well-being, to get a full picture of sleep and its impact. It’s a real-time indicator of how the nation is sleeping and how that affects us.
This insight will help us shape further research and also interventions that will help us sleep better in the future. It’s time we all started taking sleep seriously – as individuals but also as a society, given its huge impact on health.
Author: Colin Espie, Professor of Sleep Medicine, University of Oxford. Photo: Schmirn CC-BY 3.0
This article was originally published on The Conversation.
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