Key points
- About 1 in 4 shift workers has a sleep disorder linked to their working hours, with wide differences between studies[1].
- Standard CBT-I has only a modest effect in shift workers: it needs adapting[2].
- In nurses with shift work sleep disorder, an adapted digital CBT-I programme reduced insomnia by 5 points out of 28 more than an information programme[3].
- With rotating shifts, a sleep window isn't something to set on your own: do it with a professional.
Why night work disrupts sleep
Our body clock is set up for being awake in the day and asleep at night. Working nights means sleeping in the daytime, when your clock is pushing you to stay awake, in a home that is noisier and brighter. With rotating shifts, the clock never has time to adapt.
A meta-analysis of 29 studies estimates that about 26.5% of shift workers have shift work sleep disorder, with wide differences depending on the job and how it is measured[1]. The European guideline advises always asking about shift work when someone seeks help for insomnia[4].
Insomnia or a shift-related disorder?
The two look alike and often overlap. A shift-related disorder is more likely when sleep is mainly difficult around the nights you work and is fine again on your days off. Insomnia is more likely when the difficulties persist even on normal hours, at least three nights a week for three months. A doctor can help tell them apart.
CBT-I for shift workers
Standard CBT-I relies on regular hours, with a fixed wake-up time seven days a week: hard to do when nights and mornings alternate. A meta-analysis of 9 studies (363 people) found a modest effect in shift workers, and its authors call for adapted versions[2]. The large British trial of sleep restriction also excluded shift workers[5].
Adapted versions give better results. In a trial of 74 nurses with shift work sleep disorder, a digital CBT-I programme designed for night schedules reduced insomnia severity by 5 points out of 28 more than an information programme, with the effect still present three months later[3].
In ReSomnia
If you work nights, early mornings or rotating shifts, ReSomnia does not calculate an automatic sleep window: sleep restriction needs to be adapted to your hours with a professional. The sleep diary, the questionnaires and sharing with your clinician remain available.
What helps day to day
- Protect your daytime sleep: a dark room (blackout curtains, eye mask), quiet (earplugs), your phone on silent, and the people around you forewarned.
- Keep a routine around sleep, even at unusual hours: doing the same things before you sleep helps your body recognise that it is time to sleep.
- Take care on the way home after a night shift: the sleepiness is real, so avoid driving if you feel drowsy.
- Coffee: better at the start of your shift than at the end, so it doesn't get in the way of the sleep that follows. Note it in your diary to see how it affects you.
- Record your nights and your daytime sleep in a diary: it's the basis for a conversation with a doctor or clinician.