Worries about unfinished work and looming deadlines trigger brain activity, making it hard to nod off. Photo / Getty
There is all kinds of advice for falling asleep, from counting sheep to getting thicker curtains.
But writing a to-do list could provide a new solution to prevent tossing and turning, according to DailyMail.
Listing just 10 tasks you need to achieve over the next few days can help you fall asleep 15 minutes faster, neuroscientists have found.
That is because worries about unfinished work and looming deadlines, or even just the pint of milk you have forgotten to buy, trigger brain activity which makes it hard to nod off.
Writing a to-do list actually eases anxiety, it is believed, by "offloading" nagging thoughts about the next day.
When 57 people were asked to write either a list of activities they had already done or a to-do list before bed, the second group fell asleep significantly quicker.
Those who wrote detailed to-do lists got to sleep 15 minutes quicker than everyone else.
The study's lead author, Dr Michael Scullin, from Baylor University in Texas, said: "We live in a 24/7 culture in which our to-do lists seem to be constantly growing and causing us to worry about unfinished tasks at bedtime.
"Most people just cycle through their to-do lists in their heads, and so we wanted to explore whether the act of writing them down could counteract night-time difficulties with falling asleep.'
The stress of unread emails and incomplete work may explain why people most struggle to fall asleep at the start of the working week.
Almost half of people in Britain say stress or worry keeps them awake at night – 54 per cent of women and 40 per cent of men.
The US researchers asked some study participants to spend five minutes before bed writing a list, in paragraph or bullet point form, of tasks they needed to remember to complete over the next few days.
Other participants spent five minutes writing about tasks they had already completed.
Dr Scullin said: "There are two schools of thought about this. One is that writing about the future would lead to increased worry about unfinished tasks and delay sleep, while journaling about completed activities should not trigger worry.
"The alternative hypothesis is that writing a to-do list will 'offload' those thoughts and reduce worry."
Almost half of people in Britain say stress or worry keeps them awake at night – 54 per cent of women and 40 per cent of men.
To determine which theory would prove correct, researchers kept the two groups in the laboratory for four nights during the week, where their sleep was tracked using electrodes to monitor their brain activity.
The results show those who wrote the to-do lists fell asleep on average nine minutes more quickly than those asked to write about completed tasks. Those who went into more detail were able to get to sleep 15 minutes faster.
Dr Scullin, director of Baylor's sleep neuroscience and cognition laboratory, said: "It seems this is a matter of really getting things out of your head. Putting down simply that you have things to do at work or home is way too broad.
"But writing that you have to return a call to Susan, pick up groceries on the way home, get milk or petrol because you are going to be driving, this specificity helps to offload all those things unconsciously ruminating around in your head."
The study is published in the Journal of Experimental Psychology.