By Nicole Ostrow - Oct 21, 2013 3:00 PM ET

Children raised in poverty or in orphanages experience chronic stress early in life that can have long-lasting effects on the brain, setting them up for future mental and physical ailments as adults, two studies found.

The stress of poverty may affect regions in a child's brain that control emotion, according to research published today in the journal Proceedings of the National Academy of Sciences. A second study found that children who had lived in an orphanage were more anxious than those who hadn't.
Enlarge image Childhood Stress

The stress of poverty may affect regions in a child's brain that control emotion, according to research published today in the journal Proceedings of the National Academy of Sciences. Photographer: Spencer Platt/Getty Images

In childhood, the brain is still immature and developing rapidly so it is more sensitive to high-stress situations than an adult brain, said Pilyoung Kim, lead study author of the childhood poverty study. The findings from both papers suggest that early intervention programs to address chronic stress may benefit these children, the authors said.

"Long-term exposure to chronic stress is likely to cause wear and tear in children's physical and psychological systems for coping with stress over time," said Kim, an assistant professor and director of the Family and Child Neuroscience Lab at the University of Denver, in an Oct. 20 e-mail. "Living in poverty at a young age can cause long-lasting changes in brain development, which contribute to difficulties in regulating of emotions and future devastating health outcomes, including mental illness and high mortality and morbidity in adulthood."
Poverty Effects

Researchers in the poverty study looked at 54 adults at age 24. Half of those in the study were considered low income when they were 9 years old and half were not.

Using brain imaging, they found that adults who were poor as children were less able than other participants to minimize their emotional reactions to negative images by reinterpreting scenes as less harmful or mentally distancing themselves. The findings were the same even when the researchers controlled for income as adults.

In the second paper, researchers from the Weill Cornell Medical College in New York studied 16 children ages 11 and younger who had been reared in an orphanage and 10 children who hadn't.

The researchers also created a mouse model in which the maternal care of newborn mice was disrupted. This experiment enabled the researchers to simulate the orphanage experience, observe the behavior of the animals and look into their brains.

The findings suggested that the unpredictable care children receive in orphanages may alter their behavior and, as seen in the mouse model, is an early-life stress that can affect brain development.
Altered Behavior

"When growing up in an unpredictable situation such as an orphanage, you are altering the way the brain allocates resources to interpret the world around it," said Matthew Cohen, who conducted the research as part of his doctoral work at Weill Cornell. "By doing so, you end up altering the behavior of the animal or humans later on."

Early stressful experiences in childhood lead to higher rates of anxiety and depression, he said. "It's definitely more difficult to reverse the older the individual," Cohen said in a telephone interview. "The changes are more widespread if the children are in the orphanage longer."

The results suggest early intervention is needed for orphanage-reared children to help reduce risk of psychological illness, the authors wrote. About 8 million children live in orphanages worldwide, the paper said.