Inès Péborde
Will Trees Save Our Cities? : Nature, Cities & Mental Health

There has been strong evidence to support the connection between living in cities and mental illness, citing excessive stimuli, population density (causing social pressure and social isolation) as leading factors causing city dwellers to be at a higher risk of having mental disorders such a schizophrenia. Proximity to nature has been linked with insurmountable benefits to our mental health, such as reduced rates of anxiety, stress and depression, but is planting trees the solution to mitigating this urban mental health problem?
Author: Siphilele Magagula
Cover Image: Courtesy of Mike Wilson via Unsplash
Living in the city has its many advantages: access to better healthcare, better education and an improved standard of living, everything is at your fingertips, there is nothing a city cannot provide you...apart from peace of mind perhaps. The constant stimulation in a city can have negative effects on one’s psyche.
Urban Life Could Disturb The Regulation of Emotions In The Brain
Research on the link between mental illness and cities dates back to the 1930s. Since then many epidemiological studies have reported an association between the two. It seems that urban life could disturb the regulation of emotions in the brain by affecting the way the amygdala works and the level of dopamine released in the brain
Dr Andreas Meyer-Lindenberg of the Central Institute of Mental Health in Mannheim, Germany, together with his team of researchers conducted a study observing people living in cities, small towns and the countryside. They observed the brain function of these three groups through fMRIs while putting them through stress tests. Results showed that in comparison to the brains of people living in the countryside and small towns, city dwellers seemed not to handle stress as well. Further research revealed that those that grew in the city had double the risk of developing psychosis later in life.

Image courtesy of 12019 via Pixabay
The scans from Meyer-Lindenberg’s group found that those who were living or grew up in cities showed stronger activation in the amygdala and cingulate cortex (brain areas involved in processing and regulating emotion, such as stress, anxiety, phobia), compared with those from small towns and the countryside.
A separate group of researchers from Hammersmith hospital, in London are of the school of thought that erratic Dopamine levels could be a key element in the link between mental health and city living. Dopamine is a neurotransmitter that transports signals between nerve endings in the brain and plays an important role in numerous cognitive functions (mood regulation, attention span, mental drive, reward cycle, hunger craving, etc.). When a person is under stress, the level of dopamine in the brain, especially in the amygdala, increases. This high level of stress hormone triggers anxiety, anger, agitation, attention-deficits, sleep disturbances, etc. It is thought that the brains of people with schizophrenia and other psychotic disorders produce too much dopamine.

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Sensory Overload Poses A Threat To Our Mental Health
Urban living was found to raise the risk of anxiety and mood disorders by 21% and 39%. A number of social and physical and social factors could explain how the city erodes one’s well-being.
Sensory overload is a phenomenon that happens when one or more of the body's senses experiences over-stimulation from the environment. Physical stressors such as air and noise pollution are leading factors contributing to poor mental health. The rigid endless rows of concrete pavements and tall buildings without a tree or natural view in sight also act as a barrier - trapping one in the stimuli. You find yourself constantly trying to block out noises, fumes, smells, crowds and bright lights.
Another major factor is social stress felt by city dwellers. Repetitive stress has been shown to cause irregularities in dopamine levels, therefore high social density and social isolation could create a link between city living and schizophrenia and potentially other mental disorders.
Ever experienced feeling alone in a large crowd? Interestingly, German researcher and psychiatrist Dr. Mazda Adli is a keen advocate of the theory that most paradoxical, urban mixture: loneliness in crowds. In his view, “if social density and social isolation come at the same time and hit high-risk individuals … then city-stress related mental illness can be the consequence."
It appears our environment have changed much faster than what our brains can handle. And therefore we constantly feel vulnerable, under unknown threats, and stress, anxiety and psychosis are the manifestations.
How Could We Adapt Our Cities To Improve The Urban Population’s Mental Health?
A recent U.N. report projects that the proportion of people living in cities will rise from 54 percent of the world’s population in 2014 to 66 percent by 2050. With scientific research linking urban living to mental illness it is crucial that we reassess our approach to architecture and urban planning in order to combat the negative effects of city living on the mental health of the urban environment.

Image courtesy of Srecko Skrobic via Unsplash
Proximity to natural settings has been linked with a plethora of human health benefits, from reduced rates of depression to improved performance in the workplace, however planting vegetation within cities is not enough. We need to reshape our environments. Architecture and urban design need to adopt a more holistic approach to designing, looking at health-supporting human behaviours for inspiration. It is important to develop user-centered strategies which increase diversity and adaptability.
Here are some key elements to improve the living experience and furthermore the mental health of city dwellers:
1 - Green areas:
Not only does it contribute to air quality and helping to ease temperatures, vegetation has the power to humanize cities by attracting people to outdoor activities. As cities become denser, access to green public spaces will be even more important as greenery can lower people’s stress levels and enhance well-being in cities.
2 - Access to Daylight:
Over illumination in cities can be detrimental to comfort and disrupt sleep. Designers and researchers alike have highlighted the aesthetic and health benefits of natural light, one of them being that it creates an awareness and link to the outside conditions. Scientists at the Lighting Research Center, in Troy, N.Y., have reported that environments with daylight increase occupant productivity and comfort, and provide the mental and visual stimulation necessary to regulate human circadian rhythms and eradicate Seasonal Affective Disorder(SAD). Existing buildings without ample access to natural light can resort to newly developed light systems that mimic daylight - giving off the same benefits.
3 - Connection
Public space brings people together and has influence over the social dimension. Wide, accessible streets, squares, parks, sidewalks, bike paths and urban furniture stimulate interaction between people and the environment, generate a positive use of space and increase urban vitality.
4 - Encourage Movement
Physical activity (walking, cycling, sports, etc.) is widely associated with reducing causes of chronic conditions and diseases. Pedestrian-oriented as opposed to car-oriented public space, is linked to a sense of community, addressing social isolation. Design strategies to promote indoor physical activity include: providing shared indoor and outdoor exercise space, encouraging stair use, and creating attractive experiences along circulation routes (views, art, daylight, greenery). What cities could learn from rural environments is their organic nature. The rigid grid layouts of cities, which makes them easy to navigate also remove the sense of wandering and discovery. Incorporating spaces without specific functions enables spontaneous and diverse activities.
Conclusion
As Nikil Saval, author of ‘Cubed: A Secret History of the Workplace’ so eloquently put it “Design can only do so much”... We cannot take a linear approach with this, placing the burden of a global solution on architects or urban planners alone. Science working alongside architecture could bring about more insightful discoveries that will help reimagine the design of of future cities. A multidisciplinary approach is vital in the quest to create thriving human centered healing spaces. More research and experimentation to develop a evidence-based knowledge on space and mental health effects. In addition, developing more interactive and responsive design adapted to users sensory perception is key in creating healthier and more inclusive environments.