Ecotherapy: How Nature Supports Mental Health and Restores the Mind

The demands of modern life suck more out of us than they put back in. Screens, notifications and the relentless churn of traffic demand a constant, straining focus,  and the cost is evident in the irritability, forgetfulness, and the exhausted haze many of us call burnout. The good news is that nature can help. And not only that, research suggests that it may be our cheapest therapy as well. 

The science is built on two pillars. Attention Restoration Theory tells us that interaction with nature helps us recover from the burden of focusing; the biophilia hypothesis is our biology, telling us to go and find the natural world. Research in hospitals, in the deep woods and in scanning machines demonstrates that interaction with the natural world lowers stress, lifts us out of thinking patterns, and stimulates our senses. What has come out of all this research is a therapy known as ecotherapy. It has value, but it also has limitations, and those are worth knowing about. 

How Nature Heals a Fatigued Mind 

Attention Restoration Theory (ART) supposes that we have a limited budget of attention that gets spent whenever we concentrate. Stephen Kaplan (1995) called this budget directed attention, and he noted that it’s necessary for reading, working and blocking out distractions. When we exhaust this budget, our ability to concentrate suffers, and that’s mental fatigue. Natural environments, ART suggests, help us recover this budget by satisfyingly capturing our attention without demanding much of it in return. Clouds drifting overhead, leaves stirring in a breeze, and the sound of a distant stream are all examples of what the theory calls soft fascination.

A busy street will grab your attention the same way, but it also requires you to actively focus on things like road signs, billboards and navigating traffic, which is harder on your directed attention budget. (Berman, Jonides and Kaplan, 2008) tested this hypothesis by comparing hikers who walked through a park with hikers who toured downtown Ann Arbour. Both groups then took a backwards digit-span test, which measures how much we can hold in working memory. Compared to the urban walkers, people who had just finished a nature walk performed about one and a half digits better on average. 

People in the park, it seemed, had more working memory available to them. A similar test using only pictures suggested seeing natural scenes also helps; looking at images of urban settings didn’t improve performance on the directed-attention task. A later review found a number of studies showing exposure to nature improves working memory, attention control and cognitive flexibility. But it found no conclusive evidence that people who are already tired get the most benefit, leaving the value of ART as more suggestive than conclusive (Stevenson et al. 2018). 

Do We Evolved to Need Nature?  

The biophilia hypothesis attempts to explain why exposure to nature would make people feel better in the first place. E. O. Wilson (1984) coined the term biophilia to describe “the instinctive human affinity for other forms of life,” and Kellert and Wilson (1993) convened a panel of psychologists, anthropologists and designers to investigate the idea. 

The logic is that people are happiest when they feel they understand the world around them, and that humans feel this way especially around water, wildlife and vegetation places and things that were important to our ancestors for thousands of years of evolution. This isn’t a new idea; our fondness for forests and meadows is hardly revolutionary, but biophilia is an attempt to formalise and test this intuitive sense.

The hypothesis can be hard to evaluate directly, but it helps explain why we feel so good if we’re lucky enough to see a mountain or a beach, or even a tree or a squirrel on a daily basis. ART explains how nature helps us, and biophilia suggests why. The two are related  in another way as well ( Franco et al. 017) have proposed several possible evolutionary explanations for why natural sounds and odours are appealing. We’re drawn to them, these researchers believe, because our ancestors found them useful and interesting. 

How Nature Eases Stress 

Since stress can be measured objectively, researchers have been able to test how encounters with the natural world affect it. The most famous study is probably  Roger Ulrich’s (1984) research into post-surgical recovery. He found that patients recovering from gallbladder surgery with a view of trees from their windows healed faster, had fewer negative comments noted in their medical records by nurses and were less likely to request strong painkillers than patients with a view of a brick wall. Park et al. (2010) conducted a series of field experiments in Japan, asking 280  young adults to take a walk in either a forested or an urban area.

Time spent in the woods was associated with reductions in salivary cortisol, pulse and blood pressure and increases in parasympathetic (rest-and-digest) activity and decreases in sympathetic (fight-or-flight) activity. Shinrin-yoku, or “forest bathing,” as the  Japanese practice is known, involves nothing more intense than taking in the sights and sounds of the forest.

Similar results have been found in everyday city environments as well in a study that asked 36 people to spend at least 10 minutes outdoors, at least three times a week, in a place that made them feel connected to nature. Spending time in nature reduced cortisol by 21.3 per cent per hour of exposure, more than the 11.7 per cent per day decrease that’s normal for the hormone. The biggest drops happened when visitors lingered between 20 and 30  minutes(Hunter et al. 2019).  

Quieting the Mean Inner Voice 

Rumination, repetitive, negative inner speech, is a major risk factor for depression,  and exposure to nature may help disrupt it. In a study that has since become something of an archetype, Bratman et al., 2015) asked healthy volunteers to take either a 90-minute walk in a natural environment or an urban environment. Compared to people who had walked in the city, people who’d hiked in the wilderness reported less rumination after their walk, and brain scans revealed reduced blood flow to the subgenual prefrontal cortex, a region of the brain associated with rumination.

A bigger sample and inclusion of people with diagnosed depression would be helpful, since this small study can only suggest a link between nature walks and reduced rumination. (Bratman et al., 2019) A large collaborative study that represents the best current work on the power of nature found general agreement that exposure to natural environments enhanced cognitive performance and mental health, though they advise more research is needed before any specific conclusion can be drawn about what features of nature were most important. Researchers refer to these advantages as psychological ecosystem services. 

Sensory Grounding: More than Visuals 

Nature has other advantages besides the view. Most current research focuses only on visual exposure, but (Franco et al. 2017) have examined the value of sounds,  smell, taste and touch, plus three non-sensory ways: phytoncides (organic compounds given off by plants), negative air ions and microbes that nature has been found to influence human health, and conclude these sensory and sub-sensory benefits are important, though the evidence is mixed and often associative rather than conclusive. The same could be said for touch, a modality that hasn’t seen much research attention.

( Kuo 2015) has taken a different approach, cataloguing 21  possible ways that nature might influence health, one of which, improved immune functioning, she suggests might be a particularly important pathway, though other mechanisms may be at work as well.  Here “grounding” is used in the descriptive, not the clinical sense. One possible explanation, not a proven fact, is that birdsong, the scent of the soil and the feeling of the wind on your skin draw your attention outward and hold it there, in the here and now. These are the same principles that underlie mindfulness meditation and can explain why nature is sometimes seen as a form of Zen. Since none of the studies discussed here measured this effect, it’s only a hypothesis that seems worth testing. 

Ecotherapy in Practice: How Much is Enough? 

Ecotherapy is an umbrella term for nature-based approaches to mental health. Howard Clinebell helped popularise the term through his 1996 book of the same name. It includes a range of activities, from forest bathing, promoted by Japan’s forestry ministry since 1982 (Park et al., 2010), to community gardening and therapeutic walks. It also includes the simplest act of sitting in a park.

Most people would say we don’t need a lot of nature to feel better. But what does that mean in practice? According to White et al. (2019), who surveyed 19,806 English adults about their contact with nature, people who reported at least 120 minutes in natural environments during the previous week were significantly more likely to report good health and high well-being. In contrast, those who had no contact with nature were less likely to report these outcomes. The odds of reporting good health were 1.59 times higher among people spending 120 to 179 minutes in nature. Similarly, the odds of reporting high well-being were 1.23 times higher for this group.

It didn’t matter whether the 120 minutes or so was spent in a single visit or multiple visits. Additionally, the benefits appeared to taper off around 200 to 300 minutes per week. These findings should not be interpreted as a recommendation. White’s results are based on self-reports and represent an association, not a causal relationship. In contrast, Hunter’s 20-to-30-minute recommendation is based on a small sample. Together, they suggest that regular, if modest, exposure to nature can be beneficial. Moreover, this exposure can take place in an urban park as well as a wilderness setting. Most of White’s respondents, in fact, appear to have visited nature within a couple of miles of their homes. This suggests that local greenery can be as valuable as a trip to the mountains.

Limitations  

The case for nature is growing stronger with every passing year, but it has limitations that are worth being aware of. 

• Much of the research is observational. ( Hartig et al., 2014) note that observational studies dominate the field while few were rigorous enough to establish a cause-and-effect relationship. The same is true of the sensory studies, says Franco et al.  2017). 
• Samples were small and specialised. Bratman studied healthy volunteers; Hunter looked at 36 people; the subjects of Park’s study had an average age of about 22. 
• Researchers do not yet fully understand the underlying mechanisms. Stevenson et al. (2018) were unable to determine who benefits most from attention restoration, and Bratman et al. (2019)  have found that researchers don’t yet know what characteristics of nature are most important. 
• Access is unequal. Nature’s benefits depend partly on access to it, and access is uneven. Planning and policy matter just as much as the practice of nature itself  (Bratman et al., 2015; Hartig et al., 2014). 

For most people, ecotherapy should complement professional care rather than replace it. Someone with depression or anxiety shouldn’t consider a walk to be a substitute for medication or therapy. However, it can be a valuable addition to their treatment.

Conclusion 

Nature heals us in a number of ways. It gives our directed attention a chance to rest and rebuild. Additionally, it lowers our stress response and interrupts rumination. It also grounds us in the present by stimulating our senses. An evolutionary preference for living things may explain some of these benefits. However, there’s nothing unworldly about any of it, which is part of its appeal. We don’t need to take up residence in the woods to observe these advantages. Instead, we just need to make time and place for them in our urban lives, as more and more of us are doing.

• Spend approximately two hours per week in natural environments, in one or more visits (White et al., 2019).
• Aim for one 20- to 30-minute visit if possible, even if the only option is an urban park (Hunter et al., 2019). 
• Stimulate all your senses. Listen, smell and touch your surroundings as well as look (Franco et al., 2017). 
• Put the phone away and try not to use it. Hunter instructed participants not to use social media, make phone calls, or engage in conversations while spending time in natural environments.

Nature gently restores our attention, allowing us to set it down and return to it with a fresh perspective.

References +  

• Berman, M. G., Jonides, J., & Kaplan, S. (2008). The cognitive benefits of interacting with nature.  Psychological Science, 19(12), 1207–1212. https://doi.org/10.1111/j.1467-9280.2008.02225.x 
• Bratman, G. N. (2019). Nature and mental health: An ecosystem service perspective. Science Advances,  5(7). https://doi.org/10.1126/sciadv.aax0903 
• Bratman, G. N., Hamilton, J. P., Hahn, K. S., Daily, G. C., & Gross, J. J. (2015). Nature experience reduces rumination and subgenual prefrontal cortex activation. Proceedings of the National  Academy of Sciences, 112(28), 8567–8572. https://doi.org/10.1073/pnas.1510459112 
• Franco, L. S., Shanahan, D. F., & Fuller, R. A. (2017). A Review of the Benefits of Nature Experiences:  More Than Meets the Eye. International Journal of Environmental Research and Public Health,  14(8), 864. https://doi.org/10.3390/ijerph14080864 
• Hartig, T., Mitchell, R., de Vries, S., & Frumkin, H. (2014). Nature and Health. Annual Review of Public  Health, 35(1), 207–228. https://doi.org/10.1146/annurev-publhealth-032013-182443 
• Hunter, M. C. R., Gillespie, B. W., & Chen, S. Y.-P. (2019). Urban Nature Experiences Reduce Stress in the Context of Daily Life Based on Salivary Biomarkers. Frontiers in Psychology, 10(1).  https://doi.org/10.3389/fpsyg.2019.00722 
• Kaplan, S. (1995). The restorative benefits of nature: Toward an integrative framework. Journal of  Environmental Psychology, 15(3), 169–182. https://doi.org/10.1016/0272-4944(95)90001-2
• Kuo, M. (2015). How might contact with nature promote human health? Promising mechanisms and a possible central pathway. Frontiers in Psychology, 6(1093).  https://doi.org/10.3389/fpsyg.2015.01093 
• Park, B. J., Tsunetsugu, Y., Kasetani, T., Kagawa, T., & Miyazaki, Y. (2009). The physiological effects of Shinrin-yoku (taking in the forest atmosphere or forest bathing): evidence from field experiments in 24 forests across Japan. Environmental Health and Preventive Medicine, 15(1),  18–26. https://doi.org/10.1007/s12199-009-0086-9 
• Stevenson, M. P., Schilhab, T., & Bentsen, P. (2018). Attention Restoration Theory II: a systematic review to clarify attention processes affected by exposure to natural environments. Journal of  Toxicology and Environmental Health, Part B, 21(4), 227–268. https://doi.org/10.1080/10937404.2018.1505571 
• White, M. P., Alcock, I., Grellier, J., Wheeler, B. W., Hartig, T., Warber, S. L., Bone, A., Depledge, M.  H., & Fleming, L. E. (2019). Spending at Least 120 minutes a Week in Nature Is Associated with  Good Health and Wellbeing. Scientific Reports, 9(1).  https://doi.org/https://doi.org/10.1038/s41598-019-44097-3