Green Space and Mental Health: Pathways, Impacts and Gaps
Around the globe, mental health disorders are a significant and growing cause of ill health and early death, with the burden of such diseases increasing by more than a third between 1990 and 2010. Almost a third of all Canadians have experienced a mental illness at some point during their lifetimes. A Statistics Canada survey reported the most commonly reported illnesses to be mood disorders, including major depression and bipolar disorder (5.4%), followed by substance use disorders (at 4.4%), and generalized anxiety disorders (2.6%). These disorders often result in significant detrimental effects on an individual’s physical, emotional, and social well-being, making them the leading cause of years lived with disability worldwide.
The chronic nature of many mental illnesses, and their impact on an individual’s ability to seek and maintain full employment, also increases the economic burden they pose, estimated to be as high as $52 billion in 2006 in Canada alone. The roots of mental illness (and well-being) are multifactorial, including biological, socioeconomic, and environmental factors. A comprehensive approach, as proclaimed by the Mental Health Commission of Canada, includes an evaluation of the impact of environmental features on the development, progression, and treatment of mental health conditions. In this regard, a large body of evidence has been developed on the impact of various features of the natural and built environment on mental health, particularly in the urban context. One feature that bridges both of these domains is “green space”: natural areas such as parks, forests, and community gardens that often stand in stark contrast to the vast expanses of concrete, brick, and glass that comprise most modern cities’ surroundings. Many municipalities in Canada and abroad have committed to providing accessible, high-quality green space to residents, but these plans are often not guided by the potential public health benefits. Assessing scientific evidence regarding the relationship between green space and mental health is essential to inform the development of healthy, sustainable communities.
The primary objectives of this review are to:
- Describe the principal pathways linking green space to mental health, and evidence supporting these suggested mechanisms and;
- Assess the peer-reviewed epidemiological literature regarding the impact of green space on the mental health of healthy individuals and on those diagnosed with mental health disorders.