Daily Step Count and Depression in Adults: A Systematic Review and Meta-Analysis.

Importance: Recent evidence syntheses have supported the protective role of daily steps in decreasing the risk of cardiovascular disease and all-cause mortality. However, step count-based recommendations should cover additional health outcomes. Objective: To synthesize the associations between objectively measured daily step counts and depression in the general adult population. Data Sources: In this systematic review and meta-analysis, a systematic search of the PubMed, PsycINFO, Scopus, SPORTDiscus, and Web of Science databases was conducted from inception until May 18, 2024, to identify observational studies using search terms related to physical activity, measures of daily steps, and depression, among others. Supplementary search methods were also applied. Study Selection: All identified studies were uploaded to an online review system and were considered without restrictions on publication date or language. Included studies had objectively measured daily step counts and depression data. Data Extraction and Synthesis: This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses and Meta-analysis of Observational Studies in Epidemiology reporting guidelines. Two independent reviewers extracted the published data. Main Outcomes and Measures: Pooled effect sizes (correlation coefficient, standardized mean difference [SMD], and risk ratio [RR]) with 95% CIs were estimated using the Sidik-Jonkman random-effects method. Results: Thirty-three studies (27 cross-sectional and 6 longitudinal [3 panel and 3 prospective cohort]) involving 96 173 adults aged 18 years or older (range of mean [SD] ages: 18.6 [0.6] to 91.2 [1.6] years) were included. Daily steps were inversely correlated with depressive symptoms in both cross-sectional and panel studies. Compared with fewer than 5000 steps/d, pooled SMDs from cross-sectional studies revealed that 10 000 or more steps/d (SMD, -0.26; 95% CI, -0.38 to -0.14), 7500 to 9999 steps/d (SMD, -0.27; 95% CI, -0.43 to -0.11), and 5000 to 7499 steps/d (SMD, -0.17; 95% CI, -0.30 to -0.04) were significantly associated with fewer depressive symptoms. Pooled estimates from prospective cohort studies indicated that participants with 7000 or more steps/d had reduced risk of depression compared with their counterparts with fewer than 7000 steps/d (RR, 0.69; 95% CI, 0.62-0.77). An increase of 1000 steps/d was associated with a lower risk of depression (RR, 0.91; 95% CI, 0.87-0.94). Conclusions and Relevance: In this systematic review and meta-analysis of 33 observational studies involving 96 173 adults, higher daily step counts were associated with fewer depressive symptoms in cross-sectional and longitudinal studies in the general adult population. Further prospective cohort studies are needed to clarify the potential protective role of daily steps in mitigating the risk of depression during adulthood.