Living In Cities May Literally Be Driving Us Insane

Simply living in cities may be driving us insane. Or at least making us more likely to develop schizophrenia or various forms of psychosis. That's the fear propelling a growing body of research, which seeks to document the psychological effects of growing up and living in dense urban areas. If scientists' fears are confirmed, it'd be quite a blast of bad news, especially when paired with the fact that the world is fast moving out of rural areas and into cities. More than half the world lives in cities now, remember.

The basic premise is this: people who spend their lives in cities are more prone to be subjected to longer periods stress, and, after prolonged exposure, their bodies aren't good at tuning it out. The science journal Nature explains:

Considered from an evolutionary standpoint, the physiological stress response is definitely a good thing: it helps mammals to survive ...

Problems arise when the stress response doesn't switch off. Stress-hormone levels that stay too high for too long cause high blood pressure and suppress the immune system. And, although the mechanisms are unknown, scientists agree that severe or prolonged stress also raise the risk of psychiatric disease — most brutally in those who have a genetic predisposition, and when the stress occurs while the brain is still developing. In theory, then, the ceaseless challenges of the city could produce this kind of damaging stress. Some fear that they could end up driving an increase in mental illness around the world.

Now, there have only been a handful of studies that have actually linked rising rates of mental health to increasing urbanization — the most convincing one was published in 2003. Called the Camberwell study, here's what it found:

In 1965, health authorities in Camberwell, a bustling quarter of London's southward sprawl, began an unusual tally. They started to keep case records for every person in the area who was diagnosed with schizophrenia, depression, bipolar disorder or any other psychiatric condition. Decades later, when psychiatrists looked back across the data, they saw a surprising trend: the incidence of schizophrenia had more or less doubled, from around 11 per 100,000 inhabitants per year in 1965 to 23 per 100,000 in 1997 — a period when there was no such rise in the general population.

One possible explanation was that exposure to the city itself, and its myriad stresses, was driving the decline in mental health. Statistics collected in the United States and Germany seem to corroborate the finding. Nature notes that "In Germany, the number of sick days taken for psychiatric ailments doubled between 2000 and 2010; in North America, up to 40% of disability claims for work absence are related to depression, according to some estimates."

But nobody's making any conclusions — cities are vast, complex human ecosystems, and it's extremely difficult to pinpoint how, if, or why living in them may give rise to mental health problems. There's still a ton of study to be done, and there may be more specific reasons that city residents are suffering from mental health woes. So, scientists have embarked on ambitious projects to map entire metropolises, follow citizens with mobile app tech as they go to work, and to better understand how the urban environment causes stress.

One thing seems to be certain; better-planned cities, with ample green spaces and areas in which residents can find relief from the bustle are preferable to the concrete jungle. Research in the Journal of Epidemiology and Community Health found that city dwellers who lived closer to green spaces exhibited better mental health; they were less likely to be stressed or to suffer from more serious ailments.

Findings like that should be taken seriously; we've firmly entered the age of the city — cities are now the way most humanfolk are choosing to organize their societies. And that's a good thing; cities are more efficient, use less energy, generate less waste and pollution than sprawl does. And they can certainly be built in pleasing, less-stressful ways. If we start studying how cities impact mental health now, we all might be a good deal happier down the line, when everybody's living in them.