Sure, we all know that living in a big, noisy city can be stressful, but researchers have uncovered certain brain region changes in lifelong city dwellers—changes that could explain why these folks tend to be more stressed and have higher levels of mood disorders and psychotic illnesses such as schizophrenia, according to a study published in the journal Nature and reported by Time Inc.

For the study, a team of researchers from the University of Heidelberg in Germany and Douglas Mental Health University Institute at McGill University in Canada conducted stress tests on a small group of volunteers. Scientists used an MRI to scan participants’ brains after asking them to solve tough math problems under a deadline or while other researchers criticized their poor performance. Next, researchers grouped volunteers’ brain scan results with information they provided about where they lived or were raised.

Findings revealed people who live in cities had increased activation of the amygdala—the brain region that regulates emotions such as anxiety and fear. Researchers said the results suggested city dwellers’ brains had a more sensitive, hair-trigger response to stressful situations compared with people living in the suburbs or more rural areas.

Findings also showed the brains of folks raised in the city for their first 15 years of life registered increased activity in another region, the anterior cingulate. (The anterior cingulate regulates the body’s overall responses to stress.) What does this mean for city dwellers? That they become more alert to [stress] situations for the rest of their lives and never quite adapt to stress—whether it’s the same or different, said Jens C. Pruessner, PhD, director of aging and Alzheimer’s research at the institute.

What can city dwellers do to combat increased anxiety levels? “In general when it comes to stress, it’s important to keep a balance,” Pruessner said. “So after a period of working hard, you balance that with a period of off-time.”

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