Screen time
Observational studies link screen time to shorter sleep in children who use devices at bedtime, and to more myopia, overweight and depression, with small effects on mood. In trials, cutting family screen time raised children's activity and lowered behavior problems over 2 weeks but did not change weight in longer programs. Social media breaks gave mixed results.
Checked 2026-11-13
- Status
- A daily life factor, not a product.
- Also called
- screens, recreational screen time, phone use, smartphone use, social media, social media break, digital detox, TV time, television, video games, gaming, tablets, digital media, screens before bed, phone at bedtime, blue light, doomscrolling
- Studied for
- better sleep from cutting screens, mood, depression, anxiety, weight, eyesight, myopia in children, eye strain, blue light glasses, staying active, focus
Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on
Shown to help2
Reported risks5
- StrongLinked to about twice the odds of too little sleep in children using phones or tablets at bedtime, and to shorter, later sleep in 90% of studies reviewed.How often is not known
- StrongLinked to slightly more depression with more screen time in two meta-analyses, and to well-being differences too small to matter for policy in three large youth datasets.How often is not known
- StrongLinked to more myopia with more daily screen time in children and young people, in three meta-analyses, with odds rising about 21% per extra hour.How often is not known
- ModerateLinked to about 27% higher odds of overweight or obesity in adolescents with the most screen time, in one meta-analysis of 44 studies, with no dose-response pattern.How often is not known
- LimitedOne laboratory trial found reading on a light-emitting e-reader before bed delayed sleep and the body clock, lowered melatonin and reduced next-morning alertness, against a printed book.How often is not known
What it was studied for, and what was found
Shown to help2
Children's mental health after cutting family screen time
One trial found fewer behavioral and emotional difficulties in children after two weeks of strict family screen limits.
Compared with a control group of families [5]
The numbers and sources
- Effect
- The total difficulties score fell by 1.67 points more than in controls (95% CI -2.68 to -0.67, Cohen d 0.53). Emotional symptoms and peer problems fell (-1.03) and prosocial behavior rose (0.84) [5].
- Population
- 181 children, mean age about 9, in 89 Danish families, with leisure screen use cut to 3 hours a week or less for 2 weeks [5].
- Sources
- [5]
- Caveats
- A secondary analysis of one short trial. Parents who knew their group rated their children, and whether the effect lasts is unknown [5].
Activity and sleep after cutting family screen time
One trial found children were active about 46 minutes more a day after two weeks of strict family screen limits, with no change in sleep measured by EEG.
Compared with families told to carry on as usual [6]
The numbers and sources
- Effect
- Children's leisure non-sedentary activity rose by 45.8 minutes a day against controls (95% CI 27.9 to 63.6). Sleep measured by single-channel EEG did not differ between groups [6].
- Population
- 181 children and 164 adults in 89 Danish families whose parent used screens for leisure over 2.4 hours a day [6].
- Sources
- [6]
- Caveats
- Two weeks, with phones and tablets handed in, which is stricter than most everyday limits. 97% of children complied [6].
Mixed results1
Mood after cutting social media
Mixed results: one meta-analysis found small gains in well-being from social media breaks, another found none, and breaks shorter than a week went with worse mood.
Compared with control groups the abstract does not describe [1]; control groups in randomized trials [2]; control conditions in experimental studies of social media use [3]; people who kept using social media as usual [4]
The numbers and sources
- Effect
- Across 10 studies, social media abstinence did not change positive affect, negative affect or life satisfaction, and longer breaks did not change this [1]. Across 20 randomized trials, social media breaks had a small positive effect on well-being, and break length changed the effect on negative indicators [2]. A reanalysis of 20 reduction or abstinence studies, drawn from a meta-analysis of 27, found breaks under 1 week went with worse mental health (d -0.175) and breaks of 1 week or longer with better (d 0.156) [3]. In one trial, a 1-week break raised well-being (mean difference 4.9, 95% CI 3.0 to 6.8) and lowered depression (-2.2) and anxiety (-1.7) scores [4].
- Population
- 4,674 participants in 10 studies [1]. 20 randomized trials [2]. 20 experimental studies [3]. 154 adults, mean age 29.6 [4].
- Sources
- [1], [2], [3], [4]
- Caveats
- Participants know whether they are on a break, and most studies lasted days to weeks. The reviews differ in which studies they included [1][2].
Not shown to help2
Weight in children's screen-time programs
Not shown to change body mass index in children and teenagers in a meta-analysis of 14 trials, though the programs cut screen time by about 7 hours a week.
Compared with control groups in randomized trials [7]
The numbers and sources
- Effect
- Screen time programs cut total screen time by 6.90 hours a week (95% CI -9.19 to -4.60) and TV time by 6.17 hours a week. Body mass index and BMI z-score did not differ from control groups [7].
- Population
- 1,894 children and adolescents in 14 randomized trials [7].
- Sources
- [7]
- Caveats
- Programs varied in length and content, and the abstract gives no pooled BMI figure [7].
Blue-light filtering glasses
Not shown to ease eye strain from computer use against ordinary lenses in short trials, with effects on sleep uncertain, in a Cochrane review of 17 small trials.
Compared with non-blue-light filtering lenses [8]
The numbers and sources
- Effect
- Visual fatigue scores may not differ at under 1 week (mean difference 9.76, 95% CI -33.95 to 53.47, 120 participants, low certainty). Visual acuity probably did not differ (MD 0.00 logMAR). Of six trials of sleep, three found better sleep scores and three found no difference (very low certainty). Reported side effects included headache, discomfort and lower mood [8].
- Population
- Adults in 17 randomized trials of 5 to 156 participants, followed under 1 day to 5 weeks [8].
- Sources
- [8]
- Caveats
- No trial had a low risk of bias in every domain, and no meta-analysis was possible [8].
Amounts studied
Cohort and cross-sectional studies measured screen time by questionnaire, in hours a day or as bedtime access to or use of a device [9][10]. The family trials cut leisure screen use to 3 hours a week or less per person for 2 weeks, with smartphones and tablets handed in [5][6]. Children's screen-time programs cut screen time by about 7 hours a week [7]. Social media trials asked people to stop using some or all platforms for days to weeks, often 1 week [1][4]. The e-reader trial compared reading on a light-emitting device with a printed book in the hours before bed [11].
Risks
Reported risks5
Shorter and poorer sleep with devices at bedtime in children
Linked to about twice the odds of too little sleep in children using phones or tablets at bedtime, and to shorter, later sleep in 90% of studies reviewed.
The numbers and sources
- How common
- How often is not known: the sources give no rate.
- Effect
- Bedtime device use was linked to inadequate sleep (OR 2.17, 95% CI 1.42 to 3.32), poor sleep quality (OR 1.46) and excessive daytime sleepiness (OR 2.72, 95% CI 1.32 to 5.61). Having a device in the bedroom without using it was also linked to inadequate sleep (OR 1.79) [9]. A review of 67 studies found screen time adversely linked to sleep, mainly shorter duration and later timing, in 90% of them [10].
- Population
- 125,198 children aged 6 to 19, mean age 14.5, in 20 cross-sectional studies [9]. School-aged children and adolescents in 67 studies [10].
- Sources
- [9], [10]
- Caveats
- Observational and mostly cross-sectional, with self-reported screen time and sleep. Children who sleep poorly may reach for devices, which is reverse causation. Heterogeneity was high (I² 90% for sleep quantity) [9].
Later sleep and body clock after a light-emitting screen before bed
One laboratory trial found reading on a light-emitting e-reader before bed delayed sleep and the body clock, lowered melatonin and reduced next-morning alertness, against a printed book.
The numbers and sources
- How common
- How often is not known: the sources give no rate.
- Effect
- Reading on the e-reader, people took longer to fall asleep, felt less sleepy in the evening, secreted less melatonin, had a later circadian clock, less and later REM sleep, and lower alertness the next morning than when reading a printed book [11].
- Population
- Healthy adults in a sleep laboratory, each reading in both formats in the hours before bed [11].
- Sources
- [11]
- Caveats
- A small laboratory study. The abstract gives no sizes, and everyday device use at home may expose people to less light than the study used.
Depression
Linked to slightly more depression with more screen time in two meta-analyses, and to well-being differences too small to matter for policy in three large youth datasets.
The numbers and sources
- How common
- How often is not known: the sources give no rate.
- Effect
- In children and adolescents, higher screen time was linked to depression (OR 1.12, 95% CI 1.03 to 1.22). The link was J-shaped: against no screen time, risk was lower below 2 hours a day, lowest at 1 hour (OR 0.88, 95% CI 0.84 to 0.93) [12]. A second review found a pooled OR of 1.28 with high heterogeneity (I² 89%). The link was seen in females (OR 1.18) and not in males [13]. In three large datasets, digital technology use explained at most 0.4% of the variation in adolescent well-being [14].
- Population
- 127,714 young people in 16 studies, 12 of them cross-sectional [12]. 12 cross-sectional and 7 longitudinal studies [13]. 355,358 adolescents in three datasets [14].
- Sources
- [12], [13], [14]
- Caveats
- Observational and mostly cross-sectional. Low mood can lead to more screen use, which is reverse causation. Results depended heavily on how screen time and the reference group were defined [13][14].
Overweight in adolescents
Linked to about 27% higher odds of overweight or obesity in adolescents with the most screen time, in one meta-analysis of 44 studies, with no dose-response pattern.
The numbers and sources
- How common
- How often is not known: the sources give no rate.
- Effect
- Adolescents in the highest screen time category had higher odds of overweight or obesity than those in the lowest (OR 1.273, 95% CI 1.166 to 1.390). No dose-response relationship was found [15].
- Population
- Adolescents in 44 studies [15].
- Sources
- [15]
- Caveats
- Observational. Snacking, sleep and activity travel with screen time, and the trials in this age group found no BMI change when screen time fell [7].
Myopia in children
Linked to more myopia with more daily screen time in children and young people, in three meta-analyses, with odds rising about 21% per extra hour.
The numbers and sources
- How common
- How often is not known: the sources give no rate.
- Effect
- Each extra hour of daily screen time was linked to 21% higher odds of myopia (OR 1.21, 95% CI 1.13 to 1.30). Odds rose from 1.05 at 1 hour a day to 1.97 at 4 hours, then more slowly [16]. In cohort studies, high against low screen time had an OR of 2.39 (95% CI 2.07 to 2.76), and each extra hour a day 1.07. Computers and TV were linked to myopia, smartphones were not [17]. Smart device time alone had an OR of 1.26 (95% CI 1.00 to 1.60), and 1.77 combined with computer use [18].
- Population
- 335,524 participants, mean age 9.3, in 45 studies [16]. 19 studies of children and adolescents [17]. People aged 3 months to 33 years in 33 studies, 11 pooled [18].
- Sources
- [16], [17], [18]
- Caveats
- Screen time was self-reported in every study, and screen use often replaces time outdoors, which itself is linked to myopia. Many studies were cross-sectional [18].
Claims tested and not found
- That blue-light filtering glasses ease eye strain from screens. Trials found no clear difference in visual fatigue against ordinary lenses [8].
- That cutting children's screen time alone lowers their weight. Programs that cut screen time by about 7 hours a week did not change BMI [7].
- That a few days off social media lifts mood. One review found no change in positive or negative affect [1], and breaks under 1 week went with worse mental health in another analysis [3].
- That two weeks of family screen limits improve children's measured sleep. EEG-measured sleep did not differ from controls [6].
- That any screen time raises depression risk in young people. Against no screen time, 1 hour a day was linked to lower odds of depression (OR 0.88) [12].
Related
Sources
- Lemahieu L, Vander Zwalmen Y, Mennes M, et al. The effects of social media abstinence on affective well-being and life satisfaction: a systematic review and meta-analysis. Scientific Reports. 2025. https://doi.org/10.1038/s41598-025-90984-3
- Liu Y, Mohamad EMW, Azlan AA, Tan Y. Am I Happier Without You? Social Media Detox and Well-Being: A Meta-Analysis of Randomized Controlled Trials. Behavioral Sciences. 2025. https://doi.org/10.3390/bs15030290
- Thrul J, Devkota J, AlJuboori D, et al. Social Media Reduction or Abstinence Interventions Are Providing Mental Health Benefits: Reanalysis of a Published Meta-Analysis. Psychology of Popular Media. 2025. https://doi.org/10.1037/ppm0000574
- Lambert J, Barnstable G, Minter E, et al. Taking a One-Week Break from Social Media Improves Well-Being, Depression, and Anxiety: A Randomized Controlled Trial. Cyberpsychology, Behavior, and Social Networking. 2022. https://doi.org/10.1089/cyber.2021.0324
- Schmidt-Persson J, Rasmussen MGB, Sørensen SO, et al. Screen Media Use and Mental Health of Children and Adolescents: A Secondary Analysis of a Randomized Clinical Trial. JAMA Network Open. 2024. https://doi.org/10.1001/jamanetworkopen.2024.19881
- Pedersen J, Rasmussen MGB, Sørensen SO, et al. Effects of Limiting Recreational Screen Media Use on Physical Activity and Sleep in Families With Children: A Cluster Randomized Clinical Trial. JAMA Pediatrics. 2022. https://doi.org/10.1001/jamapediatrics.2022.1519
- Zhang P, Tang X, Peng X, et al. Effect of screen time intervention on obesity among children and adolescent: A meta-analysis of randomized controlled studies. Preventive Medicine. 2022. https://doi.org/10.1016/j.ypmed.2022.107014
- Singh S, Keller PR, Busija L, et al. Blue-light filtering spectacle lenses for visual performance, sleep, and macular health in adults. Cochrane Database of Systematic Reviews. 2023. https://doi.org/10.1002/14651858.CD013244.pub2
- Carter B, Rees P, Hale L, Bhattacharjee D, Paradkar MS. Association Between Portable Screen-Based Media Device Access or Use and Sleep Outcomes: A Systematic Review and Meta-analysis. JAMA Pediatrics. 2016. https://doi.org/10.1001/jamapediatrics.2016.2341
- Hale L, Guan S. Screen time and sleep among school-aged children and adolescents: a systematic literature review. Sleep Medicine Reviews. 2015. https://doi.org/10.1016/j.smrv.2014.07.007
- Chang AM, Aeschbach D, Duffy JF, Czeisler CA. Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proceedings of the National Academy of Sciences. 2015. https://doi.org/10.1073/pnas.1418490112
- Liu M, Wu L, Yao S. Dose-response association of screen time-based sedentary behaviour in children and adolescents and depression: a meta-analysis of observational studies. British Journal of Sports Medicine. 2016. https://doi.org/10.1136/bjsports-2015-095084
- Wang X, Li Y, Fan H. The associations between screen time-based sedentary behavior and depression: a systematic review and meta-analysis. BMC Public Health. 2019. https://doi.org/10.1186/s12889-019-7904-9
- Orben A, Przybylski AK. The association between adolescent well-being and digital technology use. Nature Human Behaviour. 2019. https://doi.org/10.1038/s41562-018-0506-1
- Haghjoo P, Siri G, Soleimani E, Farhangi MA, Alesaeidi S. Screen time increases overweight and obesity risk among adolescents: a systematic review and dose-response meta-analysis. BMC Primary Care. 2022. https://doi.org/10.1186/s12875-022-01761-4
- Ha A, Lee YJ, Lee M, Shim SR, Kim YK. Digital Screen Time and Myopia: A Systematic Review and Dose-Response Meta-Analysis. JAMA Network Open. 2025. https://doi.org/10.1001/jamanetworkopen.2024.60026
- Zong Z, Zhang Y, Qiao J, Tian Y, Xu S. The association between screen time exposure and myopia in children and adolescents: a meta-analysis. BMC Public Health. 2024. https://doi.org/10.1186/s12889-024-19113-5
- Foreman J, Salim AT, Praveen A, et al. Association between digital smart device use and myopia: a systematic review and meta-analysis. The Lancet Digital Health. 2021. https://doi.org/10.1016/S2589-7500(21)00135-7