Kids PTSD Symptoms Are Linked to Poor Hippocampus Function


A new study at Stanford University School of Medicine and Lucile Packard Children's Hospital is concluding that psychological trauma can leave a great trail of damage in a child's brain. The new study provides the first piece of evidence that children with symptoms of post-traumatic stress (PTSD) can suffer poor function of the hippocampus, a brain structure that stores and retrieves memories. Researchers state that this may help explain why traumatized children behave as they do and could improve treatments for these kids.

"The brain doesn't divide between biology and psychology," said Packard Children's child psychiatrist Victor Carrion, MD, the primary author of the new research. "We can use the knowledge we get from understanding brain function to improve the psychology of the individual and vice versa."

Intense stressors such as abuse or witnessing violence can make children isolate themselves from family and friends, feel disconnected from reality, experience intrusive thoughts about the trauma and struggle in school. "Post-traumatic stress is not only about the traumatic memories; it really affects daily living," said Carrion, who is an associate professor of child and adolescent psychiatry at the School of Medicine and director of Stanford’s early life stress research program.


These new findings may play a very important role in monitoring of PTSD treatments. Right now, psychologists assess treatments by looking for improvements in symptoms, but the problem is that symptoms can fluctuate from day to day. "That method has the disadvantage that we don't know what's happening at the neural level," Carrion said.

For the study, Carrion's team used functional magnetic resonance imaging to compare 16 young people who had PTSD symptoms with a control group of 11 normal youths. The scientists scanned the brains of the 10- to 17-year-old subjects during a simple test of verbal memory. Subjects read a list of words, then saw a similar list with new words added, and were asked which terms were present on the original list.

The hippocampus worked equally well in stressed and control subjects when the word list was first introduced. However, subjects with PTSD symptoms made more errors on the recall part of the test and showed less hippocampus activity than control subjects doing the same task. Those with the worst hippocampus function were also most likely to experience a specific set of PTSD including difficulty remembering the trauma, feeling cut off from others and lack of emotion.

Those with children may find the new discoveries useful Carrion said, particularly when children respond to trauma by withdrawing from people who are trying to help. Parents may sometimes misinterpret this behavior as a child's attempt to retaliate, when it actually represents an overload of the brain's normal mechanism for handling fear. "When parents understand that PTSD is real, they don't take it as personally," he said. "They become more available to their kids. That's good because the kids need them."

It's very clear that untreated PTSD can interfere with a child's normal brain development and increase the risk of other psychiatric conditions such as depression and substance abuse, Carrion concluded. "Early intervention is critical for children with post-traumatic stress," he said.