New longitudinal research published in the British Journal of Sports Medicine sheds new light on the profound impact of physical activity during early childhood on the development and trajectory of mental health disorders later in life. Drawing from an extensive Swedish birth cohort, this groundbreaking observational study provides compelling evidence suggesting that engaging children in organized sports and maintaining physical activity significantly lowers the risk of psychiatric conditions throughout childhood and adolescence. While previous studies have hinted at the protective effects of exercise on mental health, this work meticulously tracks these associations over nearly two decades, offering fresh insights and revealing intriguing sex-specific differences in how physical activity influences psychiatric outcomes.
The study leverages data from the All Babies in Southeast Sweden (ABIS) cohort, an ambitious, nationally representative birth cohort study that enrolled over 17,000 families between 1997 and 1999. This cohort offers an invaluable resource, capturing detailed information on lifestyle, environment, and health outcomes across early developmental stages and into late adolescence. Of the total children included, approximately 48% were girls and 52% boys, providing a robust sample for evaluating sex-specific variance in mental health trajectories associated with physical activity patterns. Parental reports on daily physical activity levels, time spent outdoors, and participation in organized sports were systematically collected at ages 5, 8, and 11, enabling a nuanced exploration of these factors over key developmental windows.
A critical finding from the study concerns the gradual decline in physical activity levels as children age. On average, daily physical activity decreased from around four hours at age 5 to approximately two and a half hours by age 11. This decline correlates with a significant rise in vulnerability to mental health disorders, emphasizing the potential for early intervention. Importantly, the research highlights that each additional hour of physical activity per day at age 11 is linked to a remarkable 12% reduction in the risk of any mental health diagnosis before age 18. This association underscores the critical period just before and during early puberty as a window of heightened neurodevelopmental plasticity where lifestyle factors such as exercise exert maximally protective effects.
One of the most striking revelations pertains to sex differences in protective outcomes. While increased physical activity at age 11 was associated with a 30% lower risk of developing mental health disorders among boys, this effect was not observed in girls after adjusting for confounding variables like maternal education, use of mental health medication, and adverse life events. Delving deeper, the analysis distinguishes among specific psychiatric conditions. For example, boys experienced a 29% lower risk of depression with higher physical activity at age 11, whereas for girls, the reduction was moderate at 18%. Early childhood activity levels predicted lower depression risk as early as age 5 in boys, a trend absent in girls, revealing potentially sex-dependent developmental mechanisms.
The mental health benefits extended beyond depression. The incidence of anxiety disorders was inversely associated with physical activity in boys but showed no significant relationship among girls. Boys engaging in more physical activity exhibited a 21% decreased risk of anxiety by age 5 and an even more pronounced 39% decrease by age 11. Furthermore, risks related to addiction were substantially lower among boys with higher activity levels at ages 8 and 11, with reductions exceeding 30%. In contrast, girls did not manifest similar protective trends across these psychiatric domains, suggesting that the pathways linking exercise to mental health may be modulated by biological or social factors distinct by sex.
Interestingly, the study found no significant influence of time spent outdoors on mental health outcomes, delineating the unique role that structured physical activity, particularly participation in organized sports, may play. Participation in organized sports at age 11 showed a robust association with reduced risk of first-time mental health diagnoses in both boys and girls, although the magnitude of protection varied. Boys benefited more substantially, exhibiting a 23% lower risk of any first-time mental disorder, compared to a 12% lower risk among girls, indicating that the social and physical demands of organized sports might confer diverse advantages based on sex.
The protective effects of organized sports extended to specific conditions. For example, every additional hour spent weekly in organized sports correlated with a 35% reduced risk of depression among boys but only an 11% reduction in girls. Anxiety and addiction disorders also saw decreased incidence associated with sports participation, with some nuances: girls had a 14% lower risk of anxiety and 41% lower risk of addiction, while boys experienced 21% and 30% reductions respectively. Notably, neither physical activity nor sports participation showed significant influence on the prevalence of eating or sleep disorders, emphasizing condition-specific effects and the potential complexity of underlying mechanisms.
The authors discuss potential biological and psychosocial mechanisms underpinning these gender-differentiated outcomes. One hypothesis posits that sex hormones may modulate brain development pathways differently in boys and girls, influencing the extent to which physical activity enhances neuroplasticity and stress resilience. Additionally, physical activity may directly promote brain health by enhancing neurotransmitter regulation, reducing inflammation, and improving neural connectivity. Indirect effects, such as mitigation of subclinical hyperactivity (more common in boys), and psychosocial benefits like improved self-esteem and social integration, may also contribute to these observed protective associations. Cultural and gender norms shaping the intensity and quality of physical activity experiences present further complexities.
It is critical to interpret these findings within the context of the study’s observational design. While associations are robust and longitudinal, causality cannot be definitively established. The reliance on parental recall to measure physical activity introduces the potential for reporting bias, and unmeasured confounding factors may influence observed patterns. Nonetheless, the extensive national registry linkage, large sample size, and longitudinal scope strengthen the validity and generalizability of the conclusions. These data align with broader literature emphasizing the role of physical activity in neurodevelopment and mental health but uniquely specify early puberty as a sensitive developmental period warranting targeted public health interventions.
The study advocates for an increased emphasis on promoting physical activity, especially through organized sports, during late childhood and early adolescence as a strategic approach to mitigating rising rates of psychiatric disorders among youth globally. The identification of sex-specific responses calls for tailored intervention strategies that consider differing influences of exercise based on biological sex and possibly gendered sociocultural factors. Policymakers, educators, and clinicians should prioritize creating accessible, inclusive physical activity opportunities that harness this critical window for enhancing psychological resilience.
As mental health disorders among children and adolescents reach unprecedented levels worldwide, this research signals a clarion call for reframing public health strategies. Beyond pharmacological and traditional psychological interventions, embedding physical activity into routine childhood and adolescent development emerges as a scalable, low-cost, and multifaceted approach to fostering long-term mental wellness. Future research should explore mechanistic pathways in greater detail, explore interventions targeted specifically by sex, and incorporate objective measures of physical activity to further refine understanding and optimize outcomes.
In conclusion, this comprehensive longitudinal study provides convincing evidence that physical activity during critical developmental periods substantially lowers the incidence of several common psychiatric disorders, principally depression, anxiety, and addiction-related conditions, with notably greater effects observed in boys. Organized sports play a vital role beyond unstructured play or time outdoors. These findings underscore the necessity of early, sex-sensitive physical activity promotion as a cornerstone for fostering resilience and combating the escalating burden of mental illness in modern youth populations.
Subject of Research: People
Article Title: Impact of physical activity on the incidence of psychiatric conditions during childhood: a longitudinal Swedish birth cohort study
News Publication Date: 13-May-2025
Web References: 10.1136/bjsports-2024-108148
References: British Journal of Sports Medicine, 2025, DOI: 10.1136/bjsports-2024-108148
Keywords: Mental health, Psychiatric disorders, Physical exercise, Sports medicine
Tags: All Babies in Southeast Sweden cohortchildhood development and physical activitychildhood mental health disordersearly childhood physical activity benefitslongitudinal research on exercisemental health trajectories in adolescentsobservational study on physical exerciseorganized sports participationphysical activity impact on mental healthprotective effects of exercisepsychiatric conditions in childrensex-specific differences in mental health
