Spending time on your phone in bed is a widespread habit that seems harmless. But it can have significant consequences on sleep, and more generally on health. Many studies, mainly relating to adolescents and young adults, have highlighted that screens have a harmful impact on sleep. And specialists usually recommend not using screens for 30 minutes to 1 hour before sleeping.
Several reasons explain this phenomenon: the brightness of the screens disrupt the circadian rhythm and the hormones related to sleep, the use of screens – and in particular social networks – maintains awake, and the time spent in front of a screen replaces the time that could be devoted to sleep, quite simply.
-Norwegian researchers have recently studied the effects of time spent on screens in 45,000 young adults aged 18 to 28 in Norway. They first observed that the type of activity on screens – social networks, games, podcasts … – ultimately has little impact. “We have not found any significant differences between social media and other screen activities, which suggests that using the screen itself is the key factor in sleep disturbance,” said Dr. Gunnhild Johnsen Hjetland, principal of the study, in a press release. What matters is the time spent on screens.
Precisely, the study published in the journal Frontiers in Psychiatry On March 31, 2025 concluded that each additional hour spent on a screen before sleeping increased the risk of suffering from 59 %insomnia symptoms, and reduced sleep time by 24 minutes. Precious minutes when you know that the French sleep on average less than the 7 hours recommended during the week according to Inserm.
In France, a survey conducted in 2023 by INSEE revealed that the reduction in sleep time is the main negative effect caused by screens. 43 % of 20-29 year olds say they reduce their sleep time at least once a week due to screens. To limit this impact, it is advisable to set up a routine without screens before sleeping, to remove notifications during the night, and to favor night mode in the evening. Sleep disorders affect 15 to 20 % of French people, and they can have serious consequences for physical health and mental health.
