A comprehensive Norwegian study reveals that increased physical activity during adolescence is associated with lower risk of developing depressive symptoms, particularly between ages 14-18.
Young people who maintain or increase their physical activity levels during adolescence demonstrate a reduced risk of developing depressive symptoms, according to new research published in the Journal of the American Academy of Child & Adolescent Psychiatry on 26 March 2025.
Longitudinal evidence strengthens causality claims
Researchers from the Norwegian University of Science and Technology (NTNU) conducted a large-scale longitudinal study following 873 participants from age 6 to 18 as part of the Trondheim Early Secure Study. The investigation utilised accelerometer measurements of physical activity over seven data collection points at two-year intervals, combined with clinical interviews to assess mental health status.
“Young people who are less physically active over time have an increased risk of developing symptoms of depression,” explains Professor Silje Steinsbekk from NTNU’s Department of Psychology, who led the research team.
The findings provide compelling evidence for a protective effect of physical activity against depressive symptoms, particularly during mid-to-late adolescence. Both total daily physical activity and the proportion of more intense activity were identified as protective factors.
Age-specific associations identified
The research reveals important age-related differences in the relationship between physical activity and depression. The protective effect was most pronounced between ages 14-16 and 16-18, suggesting a developmental window during which physical activity interventions might be most effective.
“Although we found that physical activity seems to protect against depression symptoms in adolescence, this did not apply to young adolescents aged 10-14,” notes Steinsbekk.
Interestingly, the researchers identified a bidirectional relationship during certain developmental periods. Between ages 10-12 and 14-16, adolescents who exhibited more depressive symptoms were subsequently more likely to become less physically active, indicating a potential negative feedback cycle.
Clinical implications for depression prevention
The study findings have significant implications for preventive mental health strategies targeting adolescents. Interventions aimed at maintaining or increasing physical activity levels from age 14 onwards may provide a protective buffer against depression, a major public health concern among this demographic.
The research found no association between sedentary time and depression symptoms, suggesting that physical activity rather than sedentary behaviour may be the more relevant target for intervention. Additionally, no sex differences were observed in the relationship between physical activity and depression risk.
This study adds to a growing body of evidence supporting physical activity as a protective factor for mental health, while providing more precise data on the developmental timing of this relationship through its robust longitudinal design and objective measurement of physical activity via accelerometry.
- Reference
Steinsbekk, S., Skoog, J., & Wichstrøm, L. (2025). Symptoms of depression, physical activity, and sedentary time: Within-person relations from age 6 to 18 in a birth cohort. Journal of the American Academy of Child & Adolescent Psychiatry.
https://doi.org/10.1016/j.jaac.2025.03.018
