A Finnish cohort finds that kids who were more active—and spent less time on screens, especially phones—reported fewer stress and depressive symptoms as teenagers.

Researchers followed children in the long‑running PANIC Study (Physical Activity and Nutrition in Children) from early school years into adolescence. At the final check‑in (average age 15.8), teens who had more physical activity—particularly supervised exercise—across childhood reported lower perceived stress and fewer depressive symptoms, while those with more total screen time, computer use, and mobile device use reported higher levels of both. Haapala et al. 2025

How the study worked. The team tracked lifestyle habits (activity, screen time, sleep, and diet quality) at three time points over eight years, combining them into a “cumulative exposure” score. Mental health was measured in adolescence using standard questionnaires. The work draws on a population‑based sample from eastern Finland and used both questionnaires and a wearable sensor to capture movement and sleep. Haapala et al. 2025

Key findings.

• Physical activity helps: Higher total activity and supervised exercise across childhood were each linked to lowerstress and depressive symptoms in the teen years. Haapala et al. 2025
• Screens weigh on mood: More screen time—especially mobile phone use—was linked to higher stress and depressive symptoms. Haapala et al. 2025
• Mixed signals from devices: Associations were not consistent when activity was measured only by sensors, highlighting how type and context of activity may matter.

What this means for families. Small, steady choices add up:

• Build regular, supervised activity (team sports, classes, coached play) into the week. Haapala et al. 2025
• Set clear, age‑appropriate screen boundaries, with special attention to phone time and social media. Clinicians in the study urge discussing screen‑time guidelines and fostering a “balanced and safe digital environment.” Haapala et al. 2025

Caveats. As an observational study from Finland, the results don’t prove cause and effect, some participants were lost to follow‑up, and social‑media habits changed during the study period—so findings should be read in context. Still, the overall signal is consistent: more movement and less screen time across childhood relate to better teen mental health. Haapala et al. 2025

Source: Haapala EA, Leppänen M, Kosola J, et al. “Childhood Lifestyle Behaviors and Mental Health Symptoms in Adolescence,” JAMA Network Open (published February 14, 2025). 

Editor’s note: This article is for information only and is not a substitute for professional medical advice.