There are countless reasons people have trouble falling asleep. It could be physiological, as in the case of airway-obstructing sleep apnea, or it could be because you’ve had too much caffeine too late in the day. But some of us experience delayed slumber for a different reason: Our racing minds can’t quite shift into a lower gear. If you fall into this hyper-vigilant category, there’s a side effect-free way to try and resolve the problem.

In a study published in the Journal of Experimental Psychology, researchers found that subjects who were tasked with writing out a to-do list for the following day (or days) before bed were able to fall asleep more quickly than other subjects who wrote about only what they had done that day.

The test, performed at Baylor University, recruited 57 people between the ages of 18 and 30 and kept them overnight in a sleep lab. Those who wrote down their planned tasks could use bullet points or paragraphs and fell asleep an average of nine minutes faster than subjects who didn’t. The more specific the list, the faster they were able to crash.

Researchers believe that the act of writing down responsibilities might be one way the brain can let go of a person’s obligations. (Thinking of what you have to do won’t have quite the same effect.) It was a small study, but considering how non-invasive it is, it might be worth trying if you're experiencing a lot of tossing and turning.

[h/t Travel+Leisure]