Growing impacts poor and stressed as an adult brain function

Newswise - Child poverty and chronic stress can lead to problems of regulation of emotions as an adult, according to research published online in the Proceedings of the National Academy of Sciences.

"Our findings suggest that the burden of stress of growing poverty can be an underlying mechanism that represents the relationship between poverty as a child and how the brain works as an adult," said Dr. K. Luan Phan, Professor of Psychiatry at the University of Illinois at Chicago College of Medicine and lead author of the study.

The study was conducted by researchers at the UIC, Cornell University, University of Michigan and the University of Denver.

The researchers found that test subjects who had family incomes less than 9 years old exhibited, as adults, increased activity in the amygdala, an area of the brain known for its role in fear and other negative emotions. These individuals showed less activity in areas of the prefrontal cortex, an area of the brain that regulates negative emotion.

Amygdala and the prefrontal cortex dysfunction has been associated with mood disorders such as depression, anxiety, impulsive aggression and substance abuse, according to the authors.

Phan said that it is well known that the negative effects of poverty can set "a cascade of increasing risk factors" for children to develop physical and psychological problems as an adult. But it is not known how child poverty might affect the functioning of the brain, particularly in emotional regulation. The ability to regulate negative emotions can provide protection against the consequences of physical and psychological health of acute and chronic stress, he said.

The study examined the associations between the poverty of children at age 9, exposure to chronic stress factors during childhood and neuronal activity in brain areas involved in emotional regulation at age 24.

49 Participants were part of a longitudinal study of child poverty. We collected data on household incomes, exhibitions stressor responses of physiological stress, social-emotional development and interactions, parents and children. Approximately half of the participants were from low-income families.

Using functional magnetic resonance imaging, the researchers evaluated the brain activity of the participants while they performed a task of emotional regulation. Subjects were asked to try to suppress negative emotions and viewing pictures, using a cognitive coping strategy.

"This serves as an index of brain-behavior of daily capacity of a person to cope with stress and negative emotions as those found" said Phan.

Perhaps the most important finding, Phan said, was that the amount of chronic stress from childhood to adolescence, such as substandard housing, overcrowding, noise and social stressors as familial disorder, violence or family separation - determines the relationship between childhood poverty and prefrontal brain function during the emotional regulation.

Co-authors include Pilyoung Kim of the University of Denver; Gary Evans of Cornell University; and Michael Angstadt, Shaun Ho, Chandra Sripada, James Swain and Israel Liberzon of the University of Michigan.

The study was supported by the national institutes of health (RC2MD004767), the Foundation of W.T. Grant, John D. and Catherine T. MacArthur Foundation Network on socioeconomic status and health, and the Robert Wood Johnson Foundation.

[This press release, together with accompanying photos, illustrations or multimedia files is online at http://news.uic.edu/?p=17630.