More Parks Are Linked to Lower Tract-Level Mental Distress in Less-Walkable Neighborhoods: A South Carolina Analysis

Mental health concerns have risen substantially over the last decade. Access to health-promoting environments, like parks, may significantly improve mental health issues such as depression and stress. Yet, despite limited access to traditional mental health services in many US communities, there remains limited research that jointly considers the role of nonclinical interventions such as park availability and neighborhood walkability. Walkability is a crucial determinant of access to green spaces and may shape how individuals benefit from park presence. This study examined the relationship between park availability and mental distress (i.e., stress, depression, and problems with emotions) and the potential moderating role of neighborhood walkability levels. For all census tracts in South Carolina ( n = 1,089), the number of available parks was extracted from Google Maps utilizing the OutScraper Application Programming Interface and expressed per 10,000 residents. For each tract, we also obtained the National Walkability Index, mental distress rates from the CDC PLACES dataset, the CDC Social Vulnerability Index, population density, percentage of people living in the same house in the past year, and the population aged 18 years old or above. Using linear regression models, we analyzed the relationship between park availability and mental distress and tested the interaction between park availability and walkability. Greater park availability was associated with lower mental distress rates ( b = −0.05, p < 0.05), adjusting for population density, residential stability, social vulnerability, and age. The association between park availability and mental distress significantly varied by walkability levels ( b = 0.004, p < 0.05). In neighborhoods with low walkability, park availability was associated with lower mental distress rates, but this association was not significant for medium- and high-walkability neighborhoods. These findings highlight the important role of park access in mitigating mental distress, especially in neighborhoods with low and medium walkability.