When the first reports of the risks of smoking came in the 1960s and 70s they were dismissed with scorn. Having smoking areas in schools was natural. Today smoking in school is unthinkable.

Some may consider a ban on using smartphones in schools to be excessive, but the growing dependency of children on digital media points towards a different attitude within a couple of decades.

An important cause for concern is that the brain's development can be negatively affected.

100,000 synapses are formed every second in a child's brain, stimulated by all forms of sensory input. They link and build up the brain's nervous network or disappear.

The nerve networks of mice exposed to digital media have been shown to change as a result. One example of the brain being affected by overuse of screens is that nearsightedness is increasing among children. The brain adjusts the eyes to looking mostly at close range.

Even more serious is that the use of smartphones in order to seek gratification has an addictive effect. The brain's reward system is stimulated in similar way to stimulation by nicotine, alcohol and drugs.

Excessive mobile use has a proven link to psychological ill health, not least among girls. A lack of affirmation leads to stress and worsened self-esteem. Mobile developers design their games to maximize addiction and maintain a dependency.

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It is well documented that increased use of digital media reduces attentiveness and learning ability. Studies have shown that school students who take notes using screens perform worse than those who use a pen and paper.

Most concerning is that many schools have already gotten rid of paper and pens. That's despite the fact that we know that training hand-eye motor skills improves learning.

Dependence on digital media can also cause a lack of empathy. Direct eye-contact cannot be replaced by communication via social media.

Sleep deprivation and psychological problems in particular have increased among young people since the smart telephone was introduced in 2007. In the USA there is talk of a so-called “Facebook depression”.

When you go to a school during a break these days you can see that many kids engage with their smartphones instead of going out and playing in the playground.

Everything suggests that the use of digital media by children should be restricted. Screens are stealing important time for development in reality.

It has been proven that small children under the age of two cannot learn anything from a screen. The opposite: speech development can be worsened when time is taken from natural parent-child contact.

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For the above reasons the mobile telephone has no place in schools. All schools should have a screen policy with simple clear rules about screen use, like schools days being mobile-free, and computers tied to lessons for school work.

Sweden does not need to be worse than France, which recently introduced a general mobile ban in schools. We believe that there is a broad consensus among both parents and responsible teachers about mobile telephones being a distraction and creating stress.

In the USA the American Academy of Pediatrics has long had strict advice on restrictions. Swedish authorities should also take in the latest research.

Children are not mature enough to take responsibility for or see the consequences of this kind of decision. It is therefore the responsibility of adults to help our children.

After some time schools will feel so much better thanks to the peace and quiet.

Screen-related stress would reduce – as would online bullying. Students would find it easier to focus and socialize – and it would stimulate being active.

This is a translation of an opinion piece written by Karolinska Institute senior pediatrics professor Hugo Lagercrantz, school physician Josef Milerad, and pediatrician Åse Victorin, originally published in Swedish by SVT Opinion.