The research behind Stillna
We build on research. These are the studies we cite in our communication and lean on while we build, with a link to every original.
Note: much of the research on screens is correlation, not causation. We cite the strongest studies, say when something is uncertain, and update this page when new results confirm or change the picture.
A phone in the bedroom disturbs sleep, even switched off
Meta-analysis of 20 studies with 125,198 children. Using the phone at bedtime roughly doubled the odds of too little sleep. Its mere presence in the room, unused, was enough for a clearly raised risk. The result holds in an updated 2024 meta-analysis.
Carter et al., JAMA Pediatrics, 2016 · read the studyThe notification alone is enough to lose the thread
Merely receiving a notification, without touching the phone, impaired concentration on a demanding task as much as actually using the phone.
Stothart et al., JEP: Human Perception and Performance, 2015 · read the studyAbout 1 in 4 young people show problematic smartphone use
41 studies with 41,871 children and young people: a median of 23 percent meet criteria for problematic smartphone use, linked to worse sleep and wellbeing. Newer data from 2024 suggest the share has grown since.
Sohn et al., BMC Psychiatry, 2019 · read the studyA phone-free school day is not enough on its own
1,227 British pupils: schools with strict phone rules had less use during the school day, but the pupils' total screen time and wellbeing did not differ. In practice the time moved to after school. That is where home, and we, can make a difference.
Goodyear et al., The Lancet Regional Health Europe, 2025 · read the studyWhen the whole family dials down, the children feel better
Randomised trial with 89 Danish families: two weeks of sharply reduced leisure screen time measurably improved the children's mental wellbeing. One of the few studies showing cause, not just correlation, and it looks exactly like what Stillna is built for.
Schmidt-Persson et al., JAMA Network Open, 2024 · read the studyThe phone on the table takes a slice of working memory
Having your own phone visible, switched off and untouched, impaired working memory compared with keeping it in another room. Later meta-analyses (2023, 2024) confirm the effect but show it is small, clearest in those most dependent on their phone.
Ward et al., Journal of the Association for Consumer Research, 2017 · read the studyHow and what matter more than how much
Meta-analysis of 42 studies with 18,905 young children: more screen time goes with weaker language development, but educational content and watching together go with stronger. The screen is not one thing; it depends on what it is used for.
Madigan et al., JAMA Pediatrics, 2020 · read the studySchool phone bans lifted the weakest pupils most
130,482 British pupils: after phone bans, results rose, most for the lowest-achieving fifth. One of the clearest quasi-experiments in the field.
Beland & Murphy, Labour Economics, 2016 · read the studyThe earlier the first phone, the larger the risks
Among 10,588 children, twelve-year-olds with their own smartphone more often had too little sleep, depressive symptoms and overweight than those without, and the earlier the phone arrived, the larger the risk. Support for the advice to wait.
Barzilay et al., Pediatrics, 2025 · read the studyThe link holds when inherited risk is accounted for
8,324 children followed for four years: more time on social media was linked to slowly rising attention problems, even after controlling for genetic ADHD risk, and with no link in the other direction. TV and gaming showed no such pattern.
Nivins et al., Pediatrics Open Science, 2025 · read the studySmall, two-way links, and content decides
Meta-analysis of 117 longitudinal studies with nearly 293,000 children: small associations in both directions between screens and emotional problems, strongest for gaming. Content and context mattered more than the minutes. Our reminder not to overstate.
Vasconcellos et al., Psychological Bulletin, 2025 · read the study