In a study on 400 people — students and working-age adults — researchers asked participants to download an app that blocked their smartphones access to the internet. They could still make calls and send texts.

Participants completed surveys before and after the study to measure their brain function and mental wellbeing.

Results showed their sustained attention — ability to focus on one subject — was boosted so much it became equivalent to the attention span of someone 10 years younger.

Ninety percent of people also reported improvements in their mental health, on a magnitude greater than that expected from taking antidepressants for two weeks.