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

Summary & key facts

This randomized trial tested whether cutting daily smartphone screen time to 2 hours or less for three weeks changed mental health in healthy students. 111 students (mean age 22.7 years, mean screen time 276 minutes/day) were assigned to the 3-week limit (n=58) or to continue usual use (n=53). After the intervention, the group that reduced screen time showed small-to-medium improvements in depressive symptoms, stress, sleep quality, and well‑being. Screen time rose again after the three weeks and outcomes moved back toward their starting levels. The authors note the study was short, not blinded, and done in healthy university students, which limits how broadly the results can be applied.

Key facts:

• Study type: a non-blinded, parallel randomized controlled trial with 111 healthy students aged 18–29 (mean age 22.68 ± 2.6 years).
• Baseline smartphone use: mean 276 ± 115.1 minutes per day (about 4.6 hours/day) across participants before the intervention.
• Intervention: 3 weeks of smartphone screen time reduction to ≤ 2 hours per day (intervention n = 58) versus usual use (control n = 53).
• Main outcomes measured: stress (PSQ), well-being (WHO‑5), depressive symptoms (PHQ‑9), and sleep quality (ISI) at baseline, post-intervention, and 6-week follow-up.
• Post-intervention effects: statistically significant group differences (p ≤ .05) at t1 for depressive symptoms (Mean Difference = 2.11, SE = 0.63, 95% CI [0.87, 3.36]), sleep quality (MD = 2.59, SE = 0.97, 95% CI [0.66, 4.51]), well‑being (
• Effect sizes reported (time × group partial eta squared): depressive symptoms η2 = 0.109, stress η2 = 0.085, well‑being η2 = 0.053, sleep quality η2 = 0.048 (described as small-to-medium effects).
• Follow-up: smartphone screen time increased rapidly after the intervention ended, and by the 6-week follow-up the measures were again close to baseline levels.
• Limitations noted by the authors: the trial was not blinded, lasted only three weeks for the intervention, included only healthy university students, and had a short follow-up, which limits how generally the results can be applied.
• Registration: the trial was preregistered on the Open Science Framework (A9K76) before enrollment.

Abstract

The study was preregistered on Open Science Framework (trial registration number: A9K76) on November 8, 2023.

Topics

Digital Mental Health Interventions Impact of Technology on Adolescents Psychological and Temporal Perspectives Research

Categories

Social Sciences Sociology and Political Science

Tags

Geometry Internal medicine Mathematics Medicine Mental health Physical therapy Psychiatry Randomized controlled trial Reduction (mathematics)