Association of residential greenspace with incident depression: a prospective cohort study.

OBJECTIVE

Depression is a major public health challenge worldwide. We aimed to examine the association between residential greenspace and incident depression in UK Biobank participants.

METHODS

We conducted a prospective cohort study of 265,311 UK Biobank participants. Cox regression models were used to examine the association between residential greenspace (300 m/1,000 m buffers) and all-cause depression, adjusting for varying degrees of confounders across 6 sequential models. Restricted cubic spline regression (RCS) was additionally adopted to assess the dose-response relationship between continuous greenspace and depression risk. A series of sensitivity, subgroup and mediation analyses were also conducted.

RESULTS

265,311 participants entered the primary analysis. During the follow-up period, incident all-cause depression occurred in 10,766 participants (4.06%). The mean greenspace percentage was 36.2% (range: 0%-100%) in the 300 m buffer and 46.0% (range: 0%-100%) in the 1,000 m buffer. In a fully adjusted multivariable model (Model 6), the adjusted hazard ratio for per 10% increment in greenspace percentage was 0.988 (95% CI, 0.979-0.996) for the 300 m buffer and 0.983 (95% CI, 0.974-0.992) for the 1,000 m buffer, corresponding to a 1.2% and 1.7% reduction in depression risk, respectively. Trend test indicated a statistically significant decreasing trend with increasing greenspace levels (P < 0.0001). Similarly, RCS displayed an inverse association of greenspace with all-cause depression, wherein higher greenspace percentage was linked to a reduced risk of depression. Results of subgroup and mediation analyses demonstrated consistent findings.

CONCLUSION

Increased residential greenspace is associated with a lower risk of all-cause depression. Urban planning strategies that enhance green environments may represent a potential approach for reducing depression risk at the population level.