Availability is not enough, but visitation and usage matter: Assessing associations between natural environments and depressive and anxiety symptoms

Background: Few studies have simultaneously considered nature availability and visitation frequency in nature-mental health research, with even fewer distinguished different types of green and blue spaces. Objective: To assess the pathways linking nature availability and visitation frequency with three mediators to depressive and anxiety symptoms, considering various green and blue space types. We also examined whether income moderated these pathways. Methods: A population-representative survey of 11,505 adults was conducted in the Netherlands. Respondents self-reported their depressive and anxiety symptoms, and visitation frequency to different types of green and blue spaces. Nature availability was captured based on respondents’ residential neighborhoods. We employed structural equation modelling to understand the theorized pathways. Results: More frequent visits to all types of green and blue spaces, except lakes, were associated with weaker depressive symptoms through one or more mediators. Residential nature availability was only indirectly associated with depressive symptoms. Green space availability was associated with depressive symptoms through forest visits and subsequently social contact, physical activity, and stress reduction. Associations between blue space availability and depressive symptoms were serially mediated by visits to rivers or beaches and subsequently by physical activity. The results for anxiety symptoms were largely insignificant. Income moderated pathways related to blue space and sports field visits. Conclusions: Merely having natural spaces in a residential neighborhood may not be sufficient to yield mental health benefits. Instead, the frequency of nature visits and the specific activities therein may play crucial roles. Planning professionals might need to prioritize promoting the visitation and usage of green and blue spaces as part of mental health promotion efforts.