7 → 11%
Share of adolescents with problematic social media use, from 2018 to 2022.
WHO Europe / HBSC 2024
Why less phone?
The phone isn't the problem. Too much of it is.
Phones connect, help and entertain. It gets difficult when use affects your control, sleep, focus or well-being. Here's what research says, factual and with sources.
Do the maths
4 hours a day. 11 years of your life.
Spend 4 hours a day on your phone from age 14, and by 80 that adds up to about 11 years. Whole years, day and night, on a screen.
Drag it to your own screen time.
11out of 80 years
01 · Numbers
What we know.
23.3%
Median share of problematic smartphone use among children and young people in studies from different countries, roughly one in four.
Sohn et al. 2019
91%
of participants improved in at least one area (mental health, well-being or attention) when their mobile internet was blocked for 2 weeks.
Castelo et al. 2025
3 h on weekdays
That's the median time young people in Switzerland say they use their smartphone, 4 hours on weekends. 99% own a smartphone.
JAMES study 2024
02 · Topics
Where research looks.
Sleep
In the meta-analysis, problematic smartphone use was linked to poorer sleep quality: the odds were about 2.6 times higher (odds ratio 2.60).
Link · Sohn et al. 2019
Focus
Without mobile internet, the objectively measured ability to sustain attention improved.
Cause, in adults · Castelo et al. 2025
Stress and anxiety
Problematic use went along with more anxiety (odds ratio 3.05) and higher perceived stress (odds ratio 1.86).
Link · Sohn et al. 2019
Mood and depression
Problematic use was linked to higher odds of depressive symptoms (odds ratio 3.17). That doesn't mean phones cause depression.
Link · Sohn et al. 2019
Social media has good sides too
According to the WHO/HBSC report, adolescents who use social media a lot but not problematically reported more support from peers and stronger social connections. It's not about zero phone, it's about use that's good for you. WHO Europe / HBSC 2024
More time outside.
03 · What screen breaks can do
Less feed, more life.
In the study by Castelo et al., participants without mobile internet spent more time socialising in person, exercising and being in nature. According to the researchers, this explains part of the improvements.
Context: the whole mobile internet was blocked, not single apps. Calls and texts still worked. The participants were adults, not teenagers. Of the 467 people, 119 fully kept the block according to the definition set in advance. Numa locks single apps and websites. We don't claim that Numa achieves the effects of this study.
Numa is not a medical device
Numa is not a medical device and does not replace advice or treatment. If you're not feeling well, talk to someone you trust or get help.
147Pro Juventute: counselling for children and young people, around the clock, free and confidential. Also via WhatsApp and email.
143Die Dargebotene Hand: phone line around the clock, anonymous and free, mainly for adults. English line: 0800 143 000, from 6 to 11 pm.
In Switzerland: 147.ch · 143.ch. In many European countries, children and young people can reach a helpline on 116 111. To find help in your country, anywhere in the world, visit findahelpline.com.