The chronic stress and poverty some people experience in childhood may lead to emotional problems in adulthood, says a study by the University of Illinois at Chicago (UIC), Cornell University, University of Denver, and University of Michigan.
The study was announced on October 21, 2013, and was published online in the “Proceedings of the National Academy of Sciences.”
“Our findings suggest that the stress-burden of growing up poor may be an underlying mechanism that accounts for the relationship between poverty as a child and how well your brain works as an adult,” said Dr. K. Luan Phan, professor of psychiatry at the UIC department of Medicine and senior author of the study.
The researchers studied activity in the amygdala, a part of the brain known to play a role in negative emotions such as fear. They also measured activity in the prefrontal cortex, which scientists believe regulate negative emotion. Amygdala and prefrontal cortex dysfunction has been associated with mood disorders such as anxiety, depression, substance abuse, and impulsive aggression.
The researchers examined 49 participants and gathered data on family income, types of stressor exposures, socio-emotional development, physchological stress responses, and parent-child interaction. Approximately half of the participants came from low-income families. The study looked at the associations between childhood poverty at age 9, stressors experienced during childhood, and the neural activity of the parts of the brain involved in emotional regulation in 24 year old adults.
Researchers used functional magnetic resonance imaging to analyze the participant’s brain activity during the performance of an emotional regulation task. The participants were asked to suppress negative emotions by using a cognitive coping strategy while viewing pictures.
Participants who had lower family incomes at age 9 showed greater activity in the amygdala and less activity in areas of the prefrontal cortex. Poverty in childhood impacted how much two regions of the prefrontal cortex were engaged during the regulation of emotions.
“This serves as a brain-behavioral index of a person’s day-to-day ability to cope with stress and negative emotions as they encounter them,” Phan said.
Perhaps the most important finding, Phan said, was that the amount of chronic stress from childhood through adolescence such as substandard housing, crowding, noise, and social stressors like family turmoil, violence or family separation determined the relationship between childhood poverty and how the prefrontal brain functions during emotional regulation.