The Association Between Green Space and Mental Health Symptoms in a Cardiac Rehabilitation Population

Background: The growth of urbanicity in the United States has brought to light certain health related concerns. Among these health outcomes associated with urban living, mental health disorders - in particular depression - seems to represent the largest public health burden. Depression is commonly seen in the general population but has a notably higher prevalence (up to 30%) in populations with medical comorbidities such as those with recent cardiac events. Cardiovascular disease is one of the biggest public health concerns today and is a major risk factor for a cardiac event; therefore, it is imperative to identify factors that could guide the reduction or prevention of depressive symptoms in this patient population. Green space in the hospital has been associated with faster recovery times, less medication use, and better self-reported health. However, those with a recent cardiac event generally recover from home. Urban green spaces near the home have been shown to reduce stress and anxiety, and it has been proposed that local environmental factors in patient populations may be associated with symptoms of mental illness. Proposed mechanisms may explain how urban green space can potentially impact mental health, including physical activity and aesthetic value. However, there is little research on the association between green space and depressive symptoms in patient populations.;Objectives: This study evaluated the association between green space near the home and depressive, anxiety, and stress symptoms in cardiac rehabilitation participants. We also examined two potential mechanisms that may explain this association: view of green space and physical activity in green spaces. Stress and anxiety levels were also evaluated with respect to interaction with green space in this population.;Methods: Participants (n=142) with recent cardiac events were recruited from the University of Rochester Medical Center and Rochester Regional Health at Unity Cardiac Rehabilitation (phase II) Centers. Patients were surveyed to ask questions about depressive, anxiety, and stress symptomology, green space around the residence, and relevant covariates. Green space was measured both objectively (using GIS-based methods) and perceptually (through participant's responses on our survey). The outcome of depressive symptoms as well as stress and anxiety was measured using the DASS-21 validated instrument and self-reported anti-depressant medication use. Crude and adjusted logistic regression models estimated the association between the various indicators of green space and DASS-21 scores. Adjusted analyses controlled for employment, age, and gender. Separate analyses were performed to evaluate the two potential mechanisms that may explain this association.;Results: In this population, those with high amounts of green space near the home had fewer cases of minor or above depression (OR: 0.41 (0.16-1.05)) than those with low or medium green space near the home. When examining green space as a continuous measure, we found significant reductions in minor or above depression with a 1% increase in green space within a half-mile from the home (OR: 0.96 (0.92-0.99)). Results using GIS-measured green space and anxiety and stress were inconsistent or null.;When participants self-reported green space quantity near the home, those with higher perceived green space within a 10 minute walk had fewer cases of minor above depression (OR: 0.36 (0.16-0.83)), anxiety (OR: 0.56 (0.26-1.23)), and stress (OR: 0.49 (0.21-1.16)). Those who perceived the closest green space within 10 minutes (compared to 11 minutes or more) also had fewer cases of depression (OR: 0.55 (0.25-1.23)) and stress (OR: 0.61 (0.26-1.41)), but not anxiety.;Viewing green space alone had some effect on mental health. Those who perceived a larger quantity of green space in view from their home had lower depression (OR: 0.79 (0.35-1.78)) and stress (OR: 0.84 (0.36-1.97)). Alternatively, those who perceived larger quantities of built environment in view from their home had slightly higher risks of all three mental illnesses. Although we saw trends in the hypothesized direction for this aim, we were underpowered to conclusively examine the association between green space view and mental health.;Finally, three constructs of physical activity in green spaces were analyzed to assess their association with our mental health outcomes (preferred exercise location, proportion of time spent in park performing physical activity, and physical activity level in parks). Those who preferred to exercise outdoors compared to indoors, those who spent their entire time in a park exercising compared to those who only were active for some or none of their park visit, and those performing moderate or vigorous exercise compared to light or none exercise in parks all had fewer cases of minor or above depression, anxiety, and stress. (Abstract shortened by ProQuest.).