Higher daily step counts associated with fewer depressive symptoms

Study finds higher daily step counts linked to fewer depressive symptoms, with 7000+ steps per day reducing depression risk in adults

In a recent study published in JAMA Network Open, a team of Spanish and South American researchers investigated the link between daily step counts, measured objectively using wearable devices, and depression in adults.

By analyzing data from 33 observational studies, the researchers explored whether increasing physical activity through walking is associated with a reduction in depressive symptoms. They provided insights into its potential role in mental health strategies.

Background

Depression is a major mental health challenge for numerous individuals worldwide. It affects the quality of life and poses substantial prevention and treatment challenges. Although various biological and lifestyle factors are believed to contribute to depression, increasing attention has been given to modifiable behaviors such as physical activity.

Previous studies have consistently highlighted the protective effects of physical activity against depression. Light-intensity activities, including walking, offer an accessible way to promote mental well-being. However, quantifying physical activity and linking it to mental health outcomes has been challenging due to reliance on self-reported data.

Wearable devices now provide a practical solution for tracking daily steps, which is a straightforward indicator of activity. While evidence already shows the benefits of higher step counts for reducing cardiovascular disease and mortality risks, research focusing on mental health outcomes, particularly depression, remains limited.

About the study

The present study employed a systematic review and meta-analysis approach to investigate the relationship between daily step counts, measured objectively using wearable devices, and depression among adults. The researchers followed established reporting guidelines and conducted a comprehensive search across multiple databases, including PubMed and Scopus, to identify observational studies up to May 2024.

The eligibility criteria included studies measuring daily steps using accelerometers, pedometers, or smartphones and assessing depression either diagnostically or through symptom scales. A total of 33 studies, comprising 27 cross-sectional and six longitudinal studies, consisting of both panel and cohort studies, were included, covering over 96,000 participants globally.

Following data extraction, the daily step counts were categorized into activity levels, and depression outcomes were analyzed as both continuous and categorical variables. The researchers also harmonized the exposure data by following a recognized classification system for step counts.

Statistical analyses included pooled effect sizes, such as correlation coefficients and risk ratios. Additionally, the study also conducted subgroup analyses to explore variations by age, sex, and device type, while sensitivity analyses and publication bias assessments were performed to ensure the robustness of findings.

The study synthesized data from diverse populations and used step measurement methods, and quality ratings were assigned to each included study. The longitudinal data allowed the researchers to examine risk associations over time, complementing cross-sectional analyses. The overall approach aimed to clarify whether daily step counts provide a protective effect against depression, laying the groundwork for potential public health applications.

Results

The study found that higher daily step counts are significantly linked to reduced depressive symptoms. In the cross-sectional analyses, walking 5,000 steps or more daily was associated with fewer depressive symptoms compared to walking less than 5,000 steps.

Furthermore, incremental increases in activity showed additional benefits, with step counts above 7,500 linked to even greater reductions in symptoms of depression. The prospective cohort data revealed that individuals achieving 7,000 or more steps daily had a notably lower risk of developing depression compared to those walking fewer steps. Specifically, every additional 1,000 steps per day corresponded to a 9% reduction in depression risk.

The effect sizes varied across step categories, with the strongest associations observed in participants achieving at least 10,000 steps daily. Furthermore, the subgroup analyses highlighted consistent benefits across different age groups and sexes, emphasizing the universal applicability of walking as a mental health intervention. The findings suggested a linear relationship, with higher activity levels yielding greater protective effects.

Additionally, the sensitivity analyses supported the robustness of the results and indicated minimal bias. However, variations in device type and measurement methods were found to have introduced some heterogeneity. Overall, the research demonstrated the potential for step-based physical activity to mitigate depression risk and highlighted walking as an accessible and scalable strategy for mental health promotion.

Conclusions

To summarize, the study reported a strong association between increased daily step counts and reduced depression risk in adults. The researchers found that walking offered significant mental health benefits and could serve as an effective tool in public health strategies. These findings also emphasized the importance of incorporating physical activity goals into mental health interventions.