Another study has linked chronic negative stress in children to changes in brain structure. There is a difference between positive and negative stress. Positive stress can provide a platform for learning, adapting and coping. Chronic negative stress such as neglect and abuse can have the opposite effect.
The research study by Wisconsin-Madison researchers revealed that the negative stressors, experienced early in life, may be associated with changing the parts of the brain responsible for learning, memory and the processing of stress and emotion. Early life stress has been linked to depression, anxiety, heart disease, cancer and a lack of educational and employment success.
The research participants consisted of 128 children around age 12 who had experienced either abuse, neglect or came from low socioeconomic households.
“We haven’t really understood why things that happen when you’re 2, 3, 4 years old stay with you and have a lasting impact,” said Seth Pollak, co-leader of the study and UW-Madison professor of psychology.
“Given how costly these early stressful experiences are for society … unless we understand what part of the brain is affected, we won’t be able to tailor something to do about it,” he said.
The researchers conducted extensive interviews with the children and their caregivers, documenting behavioral problems and their cumulative life stress. Images were taken of the children’s brains, focusing on the hippocampus and amygdala, which are involved in emotion and stress processing. These images were compared to children from middle class household who had not experienced any of the negative stressors.
The results reflected that children who experienced any of the three types of early life stress had smaller amygdalas than children who had not. Children from low socioeconomic status households and children who had been abused also had smaller hippocampal volumes.
Behavioral problems and increased cumulative life stress were also linked to smaller hippocampus and amygdala volumes.
Pollak commented on the research findings: “For me, it’s an important reminder that as a society we need to attend to the types of experiences children are having,” Pollak says. “We are shaping the people these individuals will become.”
Jamie L. Hanson, Brendon M. Nacewicz, Matthew J. Sutterer, Amelia A. Cayo, Stacey M. Schaefer, Karen D. Rudolph, Elizabeth A. Shirtcliff, Seth D. Pollak, Richard J. Davidson. Behavior Problems After Early Life Stress: Contributions of the Hippocampus and Amygdala. Biological Psychiatry, 2014; DOI: 10.1016/j.biopsych.2014.04.020