STANFORD, Calif. -- Severe stress can damage a child's brain, say researchers at the Stanford University School of Medicine and Lucile Packard Children's Hospital. The researchers found that children with post-traumatic stress disorder and high levels of the stress hormone cortisol were likely to experience a decrease in the size of the hippocampus - a brain structure important in memory processing and emotion.
Although similar effects have been seen in animal studies, this is the first time the findings have been replicated in children. The researchers focused on kids in extreme situations to better understand how stress affects brain development.
"We're not talking about the stress of doing your homework or fighting with your dad," said Packard Children's child psychiatrist Victor Carrion, MD. "We're talking about traumatic stress. These kids feel like they're stuck in the middle of a street with a truck barreling down at them."
Carrion, assistant professor of child and adolescent psychiatry at the medical school and director of Stanford's early life stress research program, and his collaborators speculate that cognitive deficits arising from stress hormones interfere with psychiatric therapy and prolong symptoms.
The children in the study were suffering from post-traumatic stress disorder, or PTSD, as a result of undergoing physical, emotional or sexual abuse, witnessing violence or experiencing lasting separation and loss. This type of developmental trauma often impairs the child's ability to reach social, emotional and academic milestones.
"We'd really like to understand why some children are more resilient than others, and what the long-term effects of extreme stress are," said Carrion, who is the first author of the research, to be published in the March issue of Pediatrics. "We know, for example, that these children are at higher risk of developing depression and/or anxiety as adults."