Higher Screen Time Tied to ADHD Symptoms, Altered Brain Structure in Children
Key Clinical Summary
- In a longitudinal US cohort of ~10,000 children aged 9 to 10 years, higher screen time predicted increased attention‑deficit/hyperactivity disorder (ADHD) symptoms over 2 years.
- Greater screen exposure was associated with reduced cortical volume and lower volume in right putamen, plus decreased cortical thickness over follow-up in several frontal and temporal regions.
- Total cortical volume partially mediated the link between screen time and ADHD symptom severity, suggesting altered brain structure may underlie behavioral changes.
Higher digital screen time in preadolescent children is associated with worsening attention-deficit/hyperactivity disorder (ADHD) symptoms and measurable alterations in brain structure, according to findings from a new study published in Translational Psychiatry.
“This study is the first to examine the relationship between screen time, ADHD symptoms, and brain structure from a developmental perspective using such a large-scale database,” said lead author Qiulu Shou, an assistant professor at the University of Fukui in Japan, in a news release.
Study Findings
A research team from the University of Fukui led by Dr Shou, Masatoshi Yamashita, and Yoshifumi Mizuno utilized longitudinal data from the Adolescent Brain Cognitive Development study to analyze screen time, ADHD symptoms, and brain structure in 10,116 children aged 9–10 at baseline and 7,880 at a 2-year follow-up. Screen time was computed as a weighted daily average combining weekday and weekend use across devices. ADHD symptoms were measured using parent-reported syndrome scales from the Child Behavior Checklist (CBCL). Brain structure was assessed using high-resolution magnetic resonance imaging (MRI; 3-Tesla) and processed via FreeSurfer. The authors used a linear mixed-effects model to assess the association between baseline screen time and changes in ADHD symptoms and brain structure after 2 years.
At baseline, higher screen time correlated with significantly greater ADHD symptoms (β = 0.109, 95% confidence interval [CI] = 0.088–0.130], p < 0.001, R2 = 0.049, d = 0.114). After 2 years, screen time remained a significant predictor of ADHD symptoms, even after controlling for baseline ADHD symptoms (β = 0.032, 95% CI = 0.021–0.089, R2 = 0.446, d = 0.045, p = 0.001).
In brain imaging analyses, greater screen time was linked to smaller right putamen (β = −0.036, 95% CI = −0.054 to −0.019, FDR-corrected p = 0.005, R2 = 0.367, d = 0.044) and lower total cortical volume (β = −0.015, 95% CI = −0.025 to -0.005, p = 0.003, R2 = 0.730, d = 0.026) at baseline. Over 2 years, higher screen use predicted reduced cortical thickness in right temporal pole (β = −0.038, 95% CI = −0.060 to 0.015, FDR-corrected p = 0.021, R2 = 0.333, d = 0.046), left superior frontal gyrus (β = −0.028, 95% CI = −0.044 to 0.011, FDR-corrected p = 0.021, R2 = 0.642, d = 0.047), and left rostral middle frontal gyrus (β = −0.030, 95% CI = −0.048 to −0.012, FDR-corrected p = 0.021, R2 = 0.549, d = 0.046).
Mediation analysis indicated total cortical volume significantly mediated the association between screen time and ADHD symptoms (indirect effect β = 0.001, 95% CI = 0.000–0.002, p = 0.023; total effect: β = 0.088, 95% CI = 0.065 to 0.111, p < 0.001), whereas putamen volume did not (β < 0.001, 95% CI = −0.001 to 0.001, p = 0.889; total effect: β = 0.088, 95% CI = 0.066 to 0.111, p < 0.001).
The authors concluded that cumulative screen exposure may influence neurodevelopment during a critical brain maturation window.
Clinical Implications
These findings are relevant for pediatricians, child psychiatrists, and mental health professionals assessing ADHD in preadolescents. The association between screen time and structural brain changes suggests that excessive digital exposure may not only exacerbate ADHD symptoms but also impact neurodevelopment.
Though effect sizes are modest, the structural mediation supports a biologically plausible pathway — smaller cortical volume may reflect delayed cortical maturation, which characterizes ADHD pathophysiology. Clinicians should systematically assess screen exposure in behavioral evaluations and consider advising families on moderating screen time as part of comprehensive ADHD management and preventive strategies.
Moreover, educational and public health policies may need to address screen time guidelines, particularly during key developmental periods.
Expert Commentary
“Our work provided some evidence toward growing concern about the association between digital media exposure and children’s mental and cognitive health,” said Dr Yamashita in a press release. “The results provide some neuroscientific evidences for the need to control screen time.”
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