June 23, 2011

More Stress, Anxiety Among Urbanites: Study

People living in rural areas are less likely to suffer stress and anxiety than those living in major cities because their brains are wired differently, according to a new study published in the journal Nature.

Although epidemiologists showed long ago that people raised in cities are more prone to mental disorders than those brought up in the countryside, the current study is the first to show that two distinct brain regions that regulate emotion and stress are affected by urban living.

"Previous findings have shown that the risk for anxiety disorders is 21 percent higher for people from the city, who also have a 39 percent increase for mood disorders," said co-author Jens Pruessner, a researcher at Douglas Mental Health University Institute.

"In addition, the incidence for schizophrenia is almost doubled for individuals who are born and brought up in cities," he said.

"These values are a cause for concern and determining the biology behind this is the first step to remedy the trend."

Pruessner and his colleagues from the Central Institute of Mental Health in Mannheim, Germany, examined the brain activity of healthy volunteers from urban and rural areas. 

They conducted a series of functional magnetic resonance experiments that revealed that city living was associated with greater stress responses in the amygdala, an area of the brain involved with emotional regulation and mood.

In contrast, urban upbringing was found to be associated with activity in the cingulate cortex, a region involved in regulation of negative affect and stress.

"These findings suggest that different brain regions are sensitive to the experience of city living during different times across the lifespan," said Pruessner.

"These findings contribute to our understanding of urban environmental risk for mental disorders and health in general. They further point to a new approach to interface social sciences, neurosciences and public policy to respond to the major health challenge of urbanization."

The study is published June 23 in the journal Nature. 


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