Andrea Mechelli, a clinical psychologist and neuroscientist, is Professor of Early Intervention in Mental Health at King’s College London. He is the project leader on Urban Mind, a research study developed with the art foundation Nomad Projects and landscape architects J&L Gibbons, which since 2018 has been looking at how aspects of the urban environment affect mental well-being worldwide. His recent findings indicate that nature – and certain features such as natural diversity and birdsong – can boost our mental health.
We know being outside – walking, jogging or playing sports – is good for our physical health, but what role does nature play in our mental health?
Several studies show that people who live near parks, canals, rivers – any green space – are less likely to struggle with mental health issues. And this is the case even after accounting for individual differences in socioeconomics. The risk of developing depression is about 20% lower in people who live near green spaces or spend a significant amount of time near green spaces. But what we don’t know is which specific aspects of the natural environment are beneficial.
How can we access the psychological benefits of being in nature?
One of the key findings from our Urban Mind project is that you don’t need a huge park to ensure people can benefit from nature: even small pockets of green space can lead to measurable improvements in mental well-being that last over time . It is important to reframe nature as something that is all around us. So even in a dense urban environment you have access to trees, you can hear birdsong. We found that when people can see trees, there is an increase in their mental well-being, and it lasts for at least eight hours. We find similar results for birdsong. Small can still have an impact.
Active participation – when you perform an act of care for the landscape – can also be very powerful. For example, planting or caring for trees will increase biodiversity, but will also reduce air pollution and will have a direct benefit on our own mental well-being.
With an emphasis on the smaller scale, what can someone who lives in a small urban apartment or house do?
Even to have a small garden on a terrace, or not to pave your garden, but let flowers and biodiversity take place in that space. Also water the green areas around where you live. For example, there is a group of individuals in London who take care of tree pits – they plant flowers and water tree seeds. It is a very small intervention, but when people take care of the landscape where they live, they also take care of themselves.
If you focus on the bigger picture of climate change, and loss of biodiversity, it can be overwhelming. The current language can feel quite doomy because there is so much emphasis on changing our lifestyles and giving up all kinds of merchandise. And this is negative language, which is not helpful. As we reframe it in a more positive way, and we help people see that by supporting our environment and addressing climate change, we are also supporting our own health, then it becomes a win-win.
Can you tell me about your studies? It used a smartphone app; how did it work
I am a clinical psychologist who has worked in mental health services in the NHS for many years. So I’m very interested in understanding why people who live in cities are at greater risk of developing mental health conditions – a well-established finding that we’ve known for years. To understand this, we needed to move away from studies that simply reported an association between urban living and risk of mental illness; we needed to understand the specific factors.
I developed a smartphone app called Urban Mind that measured people’s environment, including both social aspects and the built aspects [the built environment]. And at the same time, the app measured how people were feeling: their levels of anxiety, stress, loneliness. I expected social aspects to be very important; for example, whether someone feels safe and included in their environment, and indeed our results suggest that they are really important. But to my surprise, the strongest effect by far was the benefit of nature. So across different countries and cultures, encounters with nature lead to an increase in mental well-being that lasts for several hours. These benefits are evident even when people have chance encounters with nature during their daily lives. For example hearing birdsong on the way to work.
Can you tell me more about the specific effects of nature that you found?
Loneliness was of interest to us, especially chronic loneliness, because it has been on the rise since the beginning of the Covid-19 pandemic and is expected to reach epidemic proportions in the next few years. We found that people are 28% less likely to feel lonely when they are in an environment that includes natural features. For example, trees, plants or birds, compared to when they are in an environment that does not include them. We found it too more diverse natural environments lead to stronger mental health than monocultural natural environments, where for example you only have grass and nothing else.
How does nature have this beneficial effect on our minds?
First, we think that nature helps to improve concentration and reduce mental fatigue. This means people’s memory and attention span improve. This is a theory that has been around for many years; there is evidence, especially in children, that there is a cognitive benefit. There is also evidence that when people have access to high-quality nature, they tend to exercise and socialize more in nature, which leads to the release of endorphins and other mood-enhancing hormones, which are good for mental health. And there is evidence that nature can help reduce stress levels. Studies show that when people spend time in nature, their blood pressure improves. Also, levels of stress-inducing hormones such as cortisol, adrenaline and norepinephrine drop.
Have health professionals check prescribe nature for mental health?
It is not part of mainstream healthcare within the NHS. So there are small projects, and the majority of these have produced really positive, promising results. It has been used in a range of mental illnesses, particularly psychosis, which is a serious mental illness. People who live in cities are more likely to develop psychosis; somehow urban environments increase risk. But spending even short periods of time in nature can lead to tangible improvements. It has also been used in people with depression – and again the results have been encouraging. So as a mental health professional, I am puzzled as to why we are not capitalizing on this resource. It’s a free intervention that can lead to measurable improvements with no side effects, which is amazing.
