For many people who struggle to get a good night’s rest, being able to switch on and off the brain circuits that control sleep would be a life-changer. The good news is that’s exactly what scientists hope to do, but first they need to get a better understanding of what’s going on.

Genes and adverse childhood experiences could result in a hyperalert brain that is good at being ready for action but gives rise to insomnia in later life, according to Professor Eus Van Someren, a sleep expert at the Netherlands Institute for Neuroscience. He is investigating the link between insomnia and depression and has discovered a strong genetic correlation among the two conditions.

Reducing the trauma associated with bad memories while someone is asleep sounds like the stuff of science fiction, but it could become a reality in 10 years thanks to a greater understanding of how the brain encodes memories during sleep.

For something that can occupy such a significant chunk of time, sleep still remains a mysterious part of our lives. Although it is known to play a role in mental and physical health, such as metabolism and memory, there is much that is still not well understood.