World Sleep Day 2026: An Interview with Professor Colin Espie

World Sleep Day Interview:

Professor Colin Espie on why better sleep helps us live better

To mark World Sleep Day, we spoke with Professor Colin Espie, Sleepio Co-Founder, Professor of Sleep Medicine at the University of Oxford, and a leading expert on insomnia and sleep health.

Professor Espie has spent decades researching how sleep works, why it goes wrong, and how we can help people restore healthy sleep using evidence-based approaches such as cognitive behavioural therapy for insomnia.

This year’s World Sleep Day theme is “Sleep Well, Live Better.” We asked him what that means in practice.

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Q: The theme of World Sleep Day this year is “Sleep Well, Live Better.” What does that phrase mean to you?

Colin: Sleep is not a luxury - it’s one of the most fundamental biological processes we have. When we sleep well, we’re giving the brain and body the opportunity to restore, regulate and reset.

Good sleep supports how we think, how we feel emotionally, how our immune system functions, and even how our metabolism works. When sleep is disrupted over time, it can start to affect almost every aspect of health.

So when we say “sleep well, live better,” it’s really quite literal: better sleep underpins better physical health, better mental health, and better day-to-day functioning.

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Q: Why do you think sleep is still underestimated when it comes to health and wellbeing?

Colin: For a long time, sleep has been treated as something passive; as if it’s simply what happens when we switch off for the night. In reality, sleep is an active and highly regulated biological process.

Another reason is that people often normalise poor sleep. Many individuals struggle with insomnia or disrupted sleep for years without realising that it’s a treatable condition.

We’re beginning to see a shift in understanding now. Sleep is increasingly recognised as one of the key pillars of health, alongside nutrition, physical activity and mental wellbeing.

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Sleep is nature’s medicine.  It’s what millions of years of evolution has provided for our health and function. We need to depend upon it, not short change it, and get help if we are struggling to sleep.

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Q: Insomnia is one of the most common sleep problems. What actually causes it?

Colin: Insomnia is rarely caused by just one thing. We tend to think of it as a combination of factors.

There are predisposing factors, such as being naturally more prone to worry or heightened alertness. Then there may be precipitating events, such as stress, illness, or a difficult life period that disrupts sleep.

Over time, people often develop perpetuating habits - behaviours or thought patterns that unintentionally keep the sleep problem going. For example, spending excessive time in bed trying to catch up on sleep, or becoming very anxious about whether sleep will happen.

Understanding those factors is key, because insomnia can be treated very effectively with cognitive behavioural approaches that address those patterns.

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Q: Many people assume sleeping tablets are the main treatment for insomnia. Is that the case?

Colin: Medication can sometimes play a role in the short term, but the first-line treatment for insomnia is cognitive behavioural therapy for insomnia (CBT-I).

CBT-I helps people retrain their sleep system by adjusting sleep habits, addressing unhelpful thoughts about sleep, and restoring a healthy relationship with the bed and bedroom.

It’s an approach with a very strong evidence base, and importantly, it helps people build skills that support healthy sleep long after treatment has finished.

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Q: What are some simple things people can do to support better sleep?

Colin: There are a few principles that make a big difference.

First, try to keep a regular sleep schedule. Our sleep system works best when it has consistent timing.

Second, think about protecting the sleep environment and making your bedroom a place associated with rest and sleep rather than wakeful activity.

And third, try not to fight sleep too hard.

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The more we struggle with sleep, the more alert the brain becomes. Sometimes stepping away from the bed for a short time and returning when sleepy can be surprisingly helpful.

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Q: You’ve spent your career researching sleep. What still fascinates you about it?

Colin: Sleep is still one of the most intriguing areas of human biology. Despite decades of research, there is still so much to understand about why we sleep the way we do and how sleep affects long-term health.

What motivates me most is the impact this knowledge can have. Sleep problems affect millions of people, but they are also among the most treatable conditions when we apply the right approaches. Helping people rediscover healthy sleep can genuinely transform their quality of life.

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Q: Finally, if there’s one message you’d like people to take away from World Sleep Day, what would it be?

Colin: Take sleep seriously. If sleep is going well, protect it; it’s a vital resource for health and wellbeing. And if sleep isn’t going well, recognise that help is available.

Good sleep is not something reserved for a lucky few. With the right support and understanding, most people can learn to sleep well again.

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