In the last twenty years research has advanced in the studies of nature and mental illnesses.

The first study conducted by Jules Pretty, an Essex Professor of Biological Science, analyzed what constitutes mental health and that "for a long time, it has been taken to mean the absence of a recognizable illness". (III) In her conducted analysis, Pretty broke down three distinct levels of human interaction with nature. The first is when an individual simply 'views' nature whether through a window or pictures of physical landscapes. The second point is the individual's relative distance to nature, including activities of walking, running, and cycling. Pretty's final point was physical involvement in nature that could involve either gardening, farming, or the most popular: hiking. Wilderness therapy has also introduced the idea of "natural and wildness experiences " as well as "their therapeutic potential, and the additional role that physical hardship can play in triggering more profound experiences". (IV)

A second study developed by the New York Academy of Sciences in 2015 studied how a natural and rural environment shaped the brain's response and development when diagnosed with a mental illness. One argument claimed was even though "urbanization has many benefits, it is also associated with increased levels of mental illness, including anxiety disorders and depression".(V) A 20-year long study also helped with "tracking well-being and mental distress of more than 10,000 people demonstrates a significant positive effect of proximity to greenspace on well-being" which can be correlated as to why hikers with mental illnesses hiked and used The Appalachian Trail for their mental and emotional coping.