Neighborhood walkability and depression in low-income adults

Background: Depression is a serious and common health condition which may be influenced by neighborhood environment. Neighborhood walkability may protect against depression by increasing social interaction or promoting physical activity. Mixed findings in prior studies may result from confounding by correlated neighborhood characteristics such as socioeconomic level or greenspace, or small study populations. Our cross-sectional study estimates the effect of walkability on depression risk in adults after accounting for neighborhood- and individual-level factors. Methods: We use a large study population of low-income adults who completed a health survey in 2009 (n=4121; Portland Metropolitan Area, Oregon). Depression screening used the Patient Health Questionnaire-2. Using geocoded residential locations, we calculated study participant exposure to neighborhood walkability, greenspace, and socioeconomic level. Neighborhood walkability was calculated from density of businesses, street intersections, and population within 0.25 miles of study participants' homes. We will analyze the association between neighborhood walkability and depression with logistic regression models for men and women separately, controlling for individual and neighborhood level covariates. Results: After controlling for relevant covariates, we hypothesize greater walkability will show a modestly significant and protective estimated effect against depression, and this association will be stronger in men than women. Conclusion: Neighborhood walkability may ameliorate depression. Even if our observed association is modest, the high prevalence of depression and potential to incorporate changes in neighborhood environment could make important contributions to improving community-wide mental health. Local environmental changes could have implications for community health.