The association between greenspace and depressive symptoms among young adults in Addis Ababa, Ethiopia

Background: Greenspaces have been shown to promote psychological health; they are understudied in regions facing epidemiologic and demographic shifts towards increased mental illness burden and a more urban population, including Ethiopia. This exploratory cross-sectional analysis characterizes greenspace distribution in Addis Ababa and estimates the overall and stratified (income and sex) associations between greenspaces and depression symptomology. Methods: Data are from young adults living in Addis Ababa in the Positive Outcomes for Orphans study. The normalized difference vegetation index (NDVI) measured greenspace exposure. The Patient Health Questionnaire 8-item scale measured depressive symptoms. Tests of spatial clustering characterized greenspace distribution. Adjusted linear regression models estimated associations between greenspace and depressive symptoms. Results: Among our analytic population (n=206; 51% male; 49% female) the median age was 22(IQR: 20-23), mean NDVI was 0.14(SD:0.44), and mean PHQ-8 was 5.33(SD:4.60). Tests of clustering revealed green-rich areas in the northeast region of the city and green-deprived areas in the center of the city. Adjusted models suggest a slight association between greenspace and depressive symptoms (β = -1.10, 95% CI: -2.76,0.57). The association was strengthened among those with income (β = -1.52, 95% CI: -4.09,1.05) and among males (β = -2.58, 95%CI: -5.38,0.21), but null among those with no income (β = -0.01, 95%CI: -1.89,1.87), and females (β = 0.26, 95%CI: -1.08, 1.58). Conclusion: Though the sample is small and estimates imprecise, this analysis suggests there may be an association between greenspace and depressive symptoms that should be explored further in pursuit of population mental health in Ethiopia.