Earth’s population, now 7.3 billion, will reach 9.7 billion by the year 2050, according the the United Nations. Most of those people will live in cities, and for most of them, the concept of personal space will seem like a fantasy.

Overcrowding of most organisms, including humans, has negative health effects that include both physical and mental symptoms. Urban planning, fortunately, offers a strategy for mental illness caused by overcrowding overcrowding, but it’s going to need the assistance of research that examines the effects of cities on people.

The concept of personal space is already radically different in different locations. People living in rural areas may rarely experience an unplanned touch, while city dwellers in the world’s metropolises can’t avoid jostling and bumping on a daily basis. That may lead to a heightened overall level of stress in people. Crowds, noise, slow commutes, and fear of crime contribute to the daily experience of stress that can be constant, as well as more serious maladies, such as mental illness.

A study published in 2003 in the British Journal of Psychiatry tracked the incidence of mental illness, including depression, schizophrenia, and bipolar disorder in southeast London. Between 1965 and 1997, the report states, “There was a continuous and statistically significant increase in the incidence of schizophrenia, which was greatest in people under 35 years of age and was not gender-specific.”

The general population at that time showed no similar increase, leading the researchers to wonder if the stress of city life was contributing to the development of mental illness.

That is a difficult concept to research, considering all the variables in play in cities. As researcher Andreas Meyer-Lindenberg told the science journal Nature, “city-stress is a big, messy concept, but I believed it should be possible to at least see if brains of city-dwellers looked somehow different.”

Meyer-Lindenberg, director of the Central Institute for Mental Health in Mannheim, Germany, devised a study that used functional magnetic resonance imaging in three independent experiments. The results strongly implicated city life.

“Cities have both health risks and benefits, but mental health is negatively affected: mood and anxiety disorders are more prevalent in city dwellers and the incidence of schizophrenia is strongly increased in people born and raised in cities,” Meyer-Lindenberg said.

Considering those conclusions, can architecture and urban planning make a difference?

“Everyone wants the city to be beautiful but no-one knows what that means,” Meyer-Lindenberg said. “Architects theorize a lot, but this type of project could deliver a scientific basis for a city code.”

So far, the “scientific basis” for a health-promoting city code has not been realised worldwide, but many architects and urban planners have been addressing the challenges. Some solutions may seem obvious, but are effective. Connection to the natural world has been proven to impact physical and mental health, so green spaces, including parks and green roofs, must be maximised.

Design for openness is also crucial. In an intensely urban world, most living spaces will be small, so long views are sometimes impossible, but lighting can be improved. Optimal size and placement of windows maximizes the experience of natural lighting, which is especially valuable for the huge numbers of urban dwellers who spend most of their time indoors. Careful design can maintain privacy as well.

Some cultures have a history of adapting to crowded cities with small and flexible spaces. As sociologist William Michelson noted in Man and His Urban Environment: A Sociological Approach, “The Japanese exemplify successful adjustment to very high densities.”

japan-house

Interior of a traditional Japanese home.

The author stated that the Japanese distinguished between private and personal spaces.

“Interiors of homes are personal, and their lack of size is compensated for by an intensity of detail,” he wrote. “Every inch is open space for utilization through physically undifferentiated use of interior space. Every room may potentially be used like any other, with only the movement of portable partitions as prerequisite.”

Finally, a recent study suggests that beautiful architecture is a simple, if not easy, tactic for promoting physical and mental health, showing that scenery – whether natural or not – has a positive impact on the well-being of urban inhabitants.