Stressed? Writing down a to-do list might help

If you find it hard to get to sleep, then a solution might be at hand – a pen and paper.

If you ever struggle to get to sleep, you might find that one of the things that keeps you awake is worrying about just how much you have to do the following day, especially if there are tasks that you've started, but not yet completed.

In a study of employees at a German IT company, those who had unfinished tasks left over at the end of the working week were more likely to think about their work problems over the weekend compared with those who were more or less on top of their workload. The researcher Christine Syrek from the University of Trier wrote that their results indicated that "the perception of not having completed the week's tasks furthers employee perseverative cognitions and impairs sleep on the weekend, even above and beyond the impact of time pressure".

Those with unfinished tasks were also more likely to find their sleep was disturbed over the weekend.

"Perseverative cognitions" are continuous thoughts about negative things that have happened in the past or might happen in the future. And they were also more likely to find their sleep was disturbed over the weekend.

Sunday nights can be particularly difficult. If you've had a lie-in that morning, you might not be as sleepy at bedtime as usual. Tomorrow it will be back to work and time to face all those undone tasks, along with some new ones, no doubt. So, what can you do to stop these whirring worries from keeping you awake?

You could count sheep. You could read a book for a while, taking yourself into a world far away from your worries. You could practise some mindfulness, concentrating on your breathing and the sensations you can detect around you. Or you could turn the light on and make a list of all those things you need to do.

Yes, that's right, I'm suggesting you deliberately bring to mind all the tasks you need to carry out and which are worrying you so much. And more than that, I'm suggesting you write them down. In black and white. You might think this is the last thing that would work, but  a study conducted in the US found it was surprisingly effective.

In fact, when Michael Scullin, director of the Sleep Neuroscience and Cognition Laboratory at Baylor University in the US asked one group of volunteers to write a list just before bed of everything they'd achieved that day, and a second group to write a to-do list, all about the tasks they had to do complete tomorrow and in the next few days, it was this second group who subsequently fell asleep more quickly.

And how much quicker? Nine minutes, no less. The scientists didn't rely on the volunteers' own assessment of their sleep (which isn't always accurate), but confirmed when they were awake and asleep through a type of sleep study known as polysomnography. This involves attaching sensors to a person's head and to other parts of the body in order to monitor their brainwaves, breathing and movements.

Now it's fair to say that Scullin's study is not a large one, but there is a psychological mechanism which could explain why he got the results he did. It's called "cognitive offloading" and it happens when a person takes a physical action to relieve a mental load. 

If you turn a map around in order to make it match the street lay-out in front of you, that's an example of cognitive offloading. You are taking away some of the mental work you need to do to orientate yourself, thereby reducing the stress on your brain and making the task of going in the right direction a little easier.

In the case of the written to-do list at bedtime, you are downloading your tasks from your mind to a piece of paper (or a phone if you prefer and if you're sure you won't be lured onto social media or your emails) in a way that reduces the need for you to think about them when you're trying to get to sleep. And instead of having the tasks swirling around in your head randomly, they are put into some sort of order. They are "filed", as it were, ready to be dealt with in due course. As an added bonus you don't have to worry about forgetting them.

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It is best to list every specific task, rather than to use general headings, even though it will make your list longer. Professor Scullin's study found that busy people who created lists of more than 10 tasks fell asleep an average of 15 minutes faster than people who didn't write out to-do lists. They also fell asleep six minutes faster than those who only compiled short lists. So, make it comprehensive.

Doing all this might sound like hard work when you're tired and about to go to sleep. But it could be worth it. Writing out your to-do list just before turning in isn't going to make your life any less busy, but it might just help you to get sleep and to worry a little less. And when you get to tomorrow, you're already ahead because you have a list of everything you need to do.

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