June 22, 2011 3:00 PM

Now we know why city living's bad for the brain

By
Jennifer Welsh
German researchers have located the brain areas linked to anxiety, depression and schizophrenia.

German researchers have located the brain areas linked to anxiety, depression and schizophrenia. 

City living can be tough on the brain — it's been linked to anxiety, depression and schizophrenia. By testing the brains of students raised or living in cities, researchers in Germany have located the brain areas linked to this stress reaction.

Previous studies have shown that city living during childhood is associated with a two- to three-fold greater chance of getting schizophrenia, and even after reaching adulthood, living in a city increases the risk for anxiety disorders by 21 percent and mood disorders by 39 percent compared with non-urban dwellers.

"If everyone was born in the country, there would be 30 percent fewer people with schizophrenia, which is a sizable reduction," said study researcher Andreas Meyer-Lindenberg, of the University of Heidelberg in Mannheim, Germany. "But, if everyone was born in the country, it would become crowded."

Big city living

To find out how city living may change the brain, the researchers scanned the brains of German students while they underwent social stress: The students were given math tests on an adaptive program that let them get only a third of the questions correct.

The program also indicated to each student that he or she had performed worse on the test than anyone who had taken it; meanwhile, the researchers pushed them to do better, telling them how important it was to perform well on the test.

During the stressful task, students who were living in cities showed increased activity in a brain region called the perigenual anterior cingulate cortex (PACC), while those who lived in cities in their early childhood (regardless of where they lived at present) showed increased activity in the amygdala. These increases were in comparison with non-city dwellers. [10 Things You Didn’t Know About the Brain]

"We were quite surprised it was that specific," Meyer-Lindenberg said. "Those two brain areas are separate but they are linked, they form a circuit."

Stressed brain regions

The amygdala and the perigenual anterior cingulate cortex together form a stress-response pathway in the brain, with the PACC regulating the amygdala, which then helps you process threats and temper your emotional reactions.

The researchers are looking next to see what parts of city living might influence this difference in brain activity, including factors like amount of green space available, type of neighborhood and culture of the region. These insights could help city planners build better, less anxiety-producing cities.

"We can't evade living in cities, and I'm not arguing we should," Meyer-Lindenberg told LiveScience. "But, what about the urban experience is it that influences our brains? If we find that, we can try to address it by city planning."

The study was published today (June 22) in the journal Nature.

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Add a Comment
by Peter_Sharp1 June 28, 2011 12:39 PM EDT
What does this mean for all of us living in a city? These findings show the importance of a healthy lifestyle and brain fitness for everyone living in cities. This means in other words, keeping things in balance, avoid stress situations, invest in the quality of life. Preserving you and your brain is your best defense. A good and scientifically validated Brain Training Program is a need to ensure quality of life. An excellent option available online and for free is CogniFit - http://www.cognifit.com/
Reply to this comment
by scramcannon June 22, 2011 3:57 PM EDT
Actually schizophrenia appears to be yet another vitamin D deficiency disease.

City kids have higher rates (the highest) of asthma.

Why?

Chronic vitamin D deficiency.

If you don't believe it keep paying for expensive, DANGEROUS medications.

Or just raise your blood level vitamin D to 60 ng/ml, 25 OH.

It works WONDERS...
Reply to this comment
by rf35 June 23, 2011 2:01 PM EDT
Yes, I'm sure living in a city full of pollution-spewing cars has less to do with asthma than vitamin D. Besides, if kids would go out and play in the sunshine once in a while instead of rotting on the couch with TV and video games, vitamin D deficiency (and childhood obesity) wouldn't be a problem.
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