Smartphone screen time reduction improves mental health: a randomized controlled trial

Abstract Background Smartphone screen time has risen sharply in recent years. Even though an association between smartphone use and mental health is well documented, it is still unclear whether this is simply a correlation or causality. The aim of this study is to investigate the effects of smartpho...

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Main Authors: Christoph Pieh, Elke Humer, Andreas Hoenigl, Julia Schwab, Doris Mayerhofer, Rachel Dale, Katja Haider
Format: Article
Language:English
Published: BMC 2025-02-01
Series:BMC Medicine
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Online Access:https://doi.org/10.1186/s12916-025-03944-z
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author Christoph Pieh
Elke Humer
Andreas Hoenigl
Julia Schwab
Doris Mayerhofer
Rachel Dale
Katja Haider
author_facet Christoph Pieh
Elke Humer
Andreas Hoenigl
Julia Schwab
Doris Mayerhofer
Rachel Dale
Katja Haider
author_sort Christoph Pieh
collection DOAJ
description Abstract Background Smartphone screen time has risen sharply in recent years. Even though an association between smartphone use and mental health is well documented, it is still unclear whether this is simply a correlation or causality. The aim of this study is to investigate the effects of smartphone screen time reduction on mental health indicators. Methods This non-blinded, parallel randomized controlled trial (RCT) was performed to investigate the impact of a 3-week screen time reduction to ≤ 2 h/d in healthy students on stress (PSQ), well-being (WHO-5), depressive symptoms (PHQ-9), and sleep quality (ISI) at baseline (t0), post-intervention (t1), and at follow-up (t2 = 6 weeks after t1). For the intention to treat analysis, repeated measures ANOVAs and post-hoc tests (for time as well as group differences) were performed and effect sizes were presented as partial eta squared (η2 = time × group) and group-mean differences. Results In total, 111 out of 125 healthy students (70 females; mean age = 22.68 ± 2.6 years; mean screen time = 276 ± 115.1 min/day) were randomly assigned to intervention—(n = 58; 3 weeks of screen time reduction to ≤ 2 h/day) or control group (n = 53). Although no differences were observed at baseline (t0), significant post-intervention (t1) effects of small to medium size were observed on well-being (η2 = .053), depressive symptoms (η2 = .109), sleep quality (η2 = .048), and stress (η2 = .085). Significant group differences (p ≤ .05) were found post-intervention (t1) for depressive symptoms (Mean Difference (MD) = 2.11, Standard Error (SE) = 0.63, 95% Confidence Interval (CI) [0.87, 3.36]), sleep quality (MD = 2.59, SE = 0.97, 95% CI [0.66, 4.51]), well-being (MD = -1.54, SE = 0.68, 95% CI [.-2.89, -0.18]), and stress (MD = 6.91, SE = 3.48, 95% CI [0.01, 13.81]). Screen time increased rapidly after the intervention and at follow-up the values were once again approaching the initial level. Conclusions The study highlights mental health improvements through smartphone screen time reduction. Three weeks of screen time reduction showed small to medium effect sizes on depressive symptoms, stress, sleep quality, and well-being. The results suggest a causal relationship, rather than a merely correlative one, between daily smartphone screen time and mental health. Trial registration The study was preregistered on Open Science Framework (trial registration number: A9K76) on November 8, 2023.
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spelling doaj-art-8b93a4f66b87403db91c76577cc4e1772025-08-20T03:13:12ZengBMCBMC Medicine1741-70152025-02-0123111310.1186/s12916-025-03944-zSmartphone screen time reduction improves mental health: a randomized controlled trialChristoph Pieh0Elke Humer1Andreas Hoenigl2Julia Schwab3Doris Mayerhofer4Rachel Dale5Katja Haider6Department for Psychosomatic Medicine and Psychotherapy, Krems an der Donau, University for Continuing Education KremsDepartment for Psychosomatic Medicine and Psychotherapy, Krems an der Donau, University for Continuing Education KremsFaculty of Medicine and Dentistry, Krems an der Donau, Danube Private UniversityFaculty of Medicine and Dentistry, Krems an der Donau, Danube Private UniversityDepartment for Psychosomatic Medicine and Psychotherapy, Krems an der Donau, University for Continuing Education KremsDepartment for Psychosomatic Medicine and Psychotherapy, Krems an der Donau, University for Continuing Education KremsDepartment for Psychosomatic Medicine and Psychotherapy, Krems an der Donau, University for Continuing Education KremsAbstract Background Smartphone screen time has risen sharply in recent years. Even though an association between smartphone use and mental health is well documented, it is still unclear whether this is simply a correlation or causality. The aim of this study is to investigate the effects of smartphone screen time reduction on mental health indicators. Methods This non-blinded, parallel randomized controlled trial (RCT) was performed to investigate the impact of a 3-week screen time reduction to ≤ 2 h/d in healthy students on stress (PSQ), well-being (WHO-5), depressive symptoms (PHQ-9), and sleep quality (ISI) at baseline (t0), post-intervention (t1), and at follow-up (t2 = 6 weeks after t1). For the intention to treat analysis, repeated measures ANOVAs and post-hoc tests (for time as well as group differences) were performed and effect sizes were presented as partial eta squared (η2 = time × group) and group-mean differences. Results In total, 111 out of 125 healthy students (70 females; mean age = 22.68 ± 2.6 years; mean screen time = 276 ± 115.1 min/day) were randomly assigned to intervention—(n = 58; 3 weeks of screen time reduction to ≤ 2 h/day) or control group (n = 53). Although no differences were observed at baseline (t0), significant post-intervention (t1) effects of small to medium size were observed on well-being (η2 = .053), depressive symptoms (η2 = .109), sleep quality (η2 = .048), and stress (η2 = .085). Significant group differences (p ≤ .05) were found post-intervention (t1) for depressive symptoms (Mean Difference (MD) = 2.11, Standard Error (SE) = 0.63, 95% Confidence Interval (CI) [0.87, 3.36]), sleep quality (MD = 2.59, SE = 0.97, 95% CI [0.66, 4.51]), well-being (MD = -1.54, SE = 0.68, 95% CI [.-2.89, -0.18]), and stress (MD = 6.91, SE = 3.48, 95% CI [0.01, 13.81]). Screen time increased rapidly after the intervention and at follow-up the values were once again approaching the initial level. Conclusions The study highlights mental health improvements through smartphone screen time reduction. Three weeks of screen time reduction showed small to medium effect sizes on depressive symptoms, stress, sleep quality, and well-being. The results suggest a causal relationship, rather than a merely correlative one, between daily smartphone screen time and mental health. Trial registration The study was preregistered on Open Science Framework (trial registration number: A9K76) on November 8, 2023.https://doi.org/10.1186/s12916-025-03944-zSmartphone screen timeMental healthScreen time reductionDepressionSleepStress
spellingShingle Christoph Pieh
Elke Humer
Andreas Hoenigl
Julia Schwab
Doris Mayerhofer
Rachel Dale
Katja Haider
Smartphone screen time reduction improves mental health: a randomized controlled trial
BMC Medicine
Smartphone screen time
Mental health
Screen time reduction
Depression
Sleep
Stress
title Smartphone screen time reduction improves mental health: a randomized controlled trial
title_full Smartphone screen time reduction improves mental health: a randomized controlled trial
title_fullStr Smartphone screen time reduction improves mental health: a randomized controlled trial
title_full_unstemmed Smartphone screen time reduction improves mental health: a randomized controlled trial
title_short Smartphone screen time reduction improves mental health: a randomized controlled trial
title_sort smartphone screen time reduction improves mental health a randomized controlled trial
topic Smartphone screen time
Mental health
Screen time reduction
Depression
Sleep
Stress
url https://doi.org/10.1186/s12916-025-03944-z
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