Children Glued to Phones More Likely to Become High-Strung, Depressed Teens
In case you need another reason to hold off on buying your child a phone, research shows a troubling connection between childhood screen habits and teenage mental well-being. The eight-year study, which tracked children from elementary school into adolescence, found that kids who racked up more screen time—especially on mobile devices—showed higher levels of stress and depressive symptoms as teenagers.
The study adds to the large body of research that should make parents think twice about unlimited device access, especially as more children experience mental health struggles at an early age. Between one-quarter and one-third of adolescents worldwide experience mental health problems, with symptoms typically first appearing during the teenage years. Researchers now have more concrete evidence about lifestyle factors that might help prevent psychological distress before it takes root.
Digital Habits and Mental Health: What the Research Shows
The study authors used data from the Physical Activity and Nutrition in Children (PANIC) study, which followed 187 Finnish children over eight years, from ages 6-9 into their mid-teens. Researchers regularly checked in on their physical activity, screen time, sleep patterns, and eating habits. When these children reached adolescence (average age 15.8), the researchers assessed their mental health using standardized measures of stress and depression.
The data painted a clear picture: teenagers who had accumulated more total screen time and mobile device use throughout childhood showed significantly higher levels of stress and depressive symptoms. The connection between mobile device use and depression was particularly strong, showing a “moderate effect size”—substantial in behavioral research terms.
The team found that adolescents spent nearly five hours daily on screens, with over two hours on mobile devices alone. Many parents might find these numbers unsurprising, but the mental health correlations deserve attention.
Physical activity told the opposite story. Teens who maintained higher activity levels during childhood, especially in supervised settings like sports or structured exercise programs, showed better mental health outcomes. This protective effect remained significant even after researchers accounted for factors like parental education, body composition, and puberty status.
Gender differences added another dimension to the findings. For boys, physical activity showed stronger protective effects against stress than for girls.
Surprisingly, neither diet quality nor sleep duration showed a strong relationship with teen mental health in this study. This doesn’t mean these factors aren’t important for overall health—just that screen time and physical activity may have more direct impacts on adolescent mental well-being.
More Screen Time Should Mean More Physical Activity
For parents struggling with screen time battles, this research provides compelling evidence for setting reasonable limits. The findings highlight that mobile device use specifically—more than television or computer time—warrants special attention. With smartphones and tablets becoming increasingly central to education and social connections, creating healthy boundaries becomes more challenging but potentially more important.
The study, published in JAMA Network Open, also emphasizes the value of supervised physical activities. Children who participated in more structured exercise from ages 6-15 showed fewer mental health problems in adolescence. It’s all the more reason schools and community programs aimed at promoting youth mental health should find more ways to get children moving.
Most revealing were the outcomes showing that teenagers with both low physical activity and high screen time had the worst mental health outcomes. This demonstrates that addressing either factor alone might not be as effective as a balanced approach that both limits screen time and increases physical activity.
Creating Healthier Digital Habits for Children
While conducted in Finland, the study’s findings likely apply to children in other developed countries with similar technology access patterns. As smartphone use continues rising globally, understanding its potential psychological impact grows increasingly urgent.
For families navigating the complex digital landscape, this research offers practical guidance: limit screen time (especially on mobile devices), encourage regular physical activity (particularly supervised activities like sports), and remember that these choices may affect not just current behavior but long-term mental health.
Mental health professionals and pediatricians may want to include screen time discussions in their preventive care conversations. Creating balanced digital environments and promoting consistent physical activity within supportive social contexts could become key strategies for protecting youth mental health.
Incorporating technology into children’s lives at younger ages is understandably commonplace these days. But here is another study showing why childhood habits matter. How we balance screens and physical activity today may shape the psychological landscape our children navigate tomorrow.
Points of Contention
While this study provides valuable insights, several factors warrant consideration before drawing firm conclusions:
Methodology Limitations
- High dropout rate: Only 187 of the original 504 participants completed all assessments
- Self-reporting problems: Screen time data came primarily from questionnaires, which can be inaccurate
- Measurement inconsistency: Self-reported physical activity showed mental health benefits, but device-measured activity didn’t
Interpretation Challenges
- Correlation vs. causation: The study shows associations but cannot prove screens cause mental health problems
- Missing context: The study measured time on devices but not what content children consumed
- Unmeasured influences: Family dynamics, peer relationships, and school environments weren’t fully accounted for
Relevance Questions
- Technology evolution: Data collection ended in 2017, before TikTok and pandemic-era screen use
- Cultural specificity: The Finnish context may limit applicability to other countries
- Clinical significance: The study doesn’t clarify whether the observed differences would impact day-to-day functioning
These limitations don’t invalidate the findings but suggest we should view them as part of a broader conversation about youth mental health rather than definitive proof.
Paper Summary
Methodology
The Finnish researchers designed a robust study to track children’s lifestyle behaviors over time. Starting with 504 children aged 6-9, they collected data at three points: baseline (2007-2009), 2-year follow-up, and 8-year follow-up (2015-2017). By the final assessment, 187 teens had complete data on self-reported behaviors and mental health. The team used both questionnaires and wearable devices to measure lifestyle factors. Children and parents reported physical activity and screen time through surveys, while researchers objectively tracked movement using devices combining accelerometers and heart rate monitors. Food diaries helped assess diet quality, which was scored using a Baltic Sea Diet measurement tool. To capture the cumulative effect of behaviors over eight years, the researchers calculated “area under the curve” measurements rather than looking at isolated time points. This method accounts for the entire pattern of exposure throughout childhood. When participants reached adolescence (around age 15.8), they completed two standard mental health assessments: the Cohen Perceived Stress Scale and the Beck Depression Inventory.
Results
The findings revealed clear connections between childhood behaviors and teen mental health. Higher self-reported physical activity was linked to better mental health outcomes, with statistical relationships showing small but meaningful effect sizes (standardized coefficients between -0.14 and -0.17). Screen time showed even stronger relationships with mental health problems. Total screen time was associated with both stress (coefficient 0.27) and depressive symptoms (coefficient 0.30), representing moderate effect sizes. Mobile device use showed the strongest associations of all measured factors, with coefficients of 0.28 for stress and 0.33 for depression. Computer use was linked to stress but showed a weaker relationship with depression. The research revealed some interesting gender patterns: boys seemed to benefit more from physical activity in terms of stress reduction than girls did. Unexpectedly, diet quality and measured sleep duration didn’t show significant associations with mental health outcomes. The researchers also found that adolescents with both low physical activity and high screen time showed the highest levels of mental health symptoms, suggesting these factors may work together to impact psychological well-being.
Limitations
The research team acknowledged several constraints that might affect how we interpret their findings. Their final sample size of 187 participants limits statistical power, especially when analyzing differences between boys and girls. Many potential participants dropped out during the eight-year study period, which could skew results if those who left differed systematically from those who stayed. While the researchers used advanced methods to measure cumulative exposure to different behaviors, their approach might not capture short-term fluctuations between measurement points. The study didn’t assess important contextual factors, such as the specific content of screen time or the social aspects of physical activities. Since the follow-up ended in 2017, the findings may not fully apply to current technology patterns, particularly given rapid changes in social media platforms. Although the researchers measured sleep duration, they didn’t assess sleep quality or how long it took participants to fall asleep—factors that might have different relationships with mental health. Finally, while the study shows correlations between lifestyle behaviors and mental health, it can’t prove that one directly causes the other.
Discussion and Takeaways
The researchers concluded that reducing screen time might be more important than increasing physical activity for promoting youth mental health. The specific type of sedentary behavior matters—screen time, especially mobile device use, showed stronger associations with mental health problems than overall sedentary time. This suggests targeted interventions for children who have high screen use and low physical activity levels. The researchers proposed several mechanisms that might explain these connections, including how screen time can disrupt sleep, harm body image, and lower self-esteem. On the flip side, physical activity might benefit mental health by improving physical self-esteem. Based on these findings, the research team recommends that health professionals discuss screen time guidelines with families, emphasizing balanced digital environments and consistent physical activity within supportive social contexts. The study highlights the importance of helping children develop healthy lifestyle patterns early, as these habits may have lasting effects on mental well-being through adolescence.
Funding and Disclosures
The PANIC study received substantial financial support from multiple Finnish and international organizations. Funding came from the Research Council of Finland, various government ministries (Education and Culture, Social Affairs and Health), the Kuopio University Hospital Research Committee, Finnish Innovation Fund Sitra, Social Insurance Institution of Finland, and numerous foundations focused on health, including the Finnish Cultural Foundation, Foundation for Pediatric Research, Diabetes Research Foundation, Finnish Foundation for Cardiovascular Research, and several private foundations (Juho Vainio, Paavo Nurmi, Yrjö Jahnsson). The city of Kuopio also provided support. The researchers reported no conflicts of interest related to the study. The Hospital District of Northern Savo’s ethics committee approved the study protocol in 2006 and extended approval through the 8-year follow-up period.
Publication Information
This research article, “Childhood Lifestyle Behaviors and Mental Health Symptoms in Adolescence,” appeared in JAMA Network Open on February 14, 2025 (Volume 8, Issue 2, Article ID e2460012). Dr. Eero A. Haapala from the Sports and Exercise Medicine department at the University of Jyväskylä led the research team, which included 12 additional collaborators from Finnish institutions and the University of Newcastle in Australia. The study followed scientific reporting guidelines established for observational studies (STROBE) and conducted all procedures according to principles in the Declaration of Helsinki. This open-access publication means the full research is available for free to anyone interested in reading the complete findings.