While urbanites have long suspected it, scientists have actually identified what makes life in the big city so much more, well, unhealthy. They say their research has found that the parts of the brain that deal with stress and emotion don't handle crowds well.
That could be why people who are born and raised in big cities have more depression, more anxiety and a higher incidence of schizophrenia, scientists say.
And while the researchers behind the study aren't sure why cities have so many negative effects on people, they do know that folks do better when they are around a lot of green spaces. Such exposure reduces stress, makes us less vulnerable to depression and boosts health overall.
"Previous findings have shown that the risk for anxiety disorders is 21 per cent higher for people from the city, who also have a 39 per cent increase for mood disorders," said Dr. Jens Pruessner of the Douglas Mental Health University Institute in Quebec, who helped conduct the study.
"In addition, the incidence of schizophrenia is almost doubled for individuals born and brought up in cities. These values are a cause for concern," he added.
Pruessner, along with colleagues from the University of Heidelberg in Germany, monitored the brain waves of adults who worked out mental math problems under pressure. MRI examinations of subjects who lived in cities reacted much differently to stress, the researchers - who published their findings in the journal Nature - found.
The study found that the region of the brain - the amygdala, which involves mood and emotions - was much more active in city dwellers.
In addition, those living in large cities also had more active cingulate cortexes, which helps regulate stress, while they were figuring their math problems.
Researchers said a larger study would be needed to confirm their results, as they aren't sure exactly why cities may cause the kind of health problems they seem to be causing. That said, other studies have shown that people who live in rural areas are less prone to heart attacks and strokes - two conditions known to be exacerbated by stress and anxiety.
One study, at Essex University in Britain, showed that spending just five minutes in green spaces reduces stress.
So, it seems simple: If you want to cut your anxiety and live a little longer, you might just be better off leaving that city life behind.