Dart Center for Journalism and Trauma

According to a meta-analysis of 19 studies, trauma and PTSD symptoms may precede a reduction in the size of the hippocampus, a part of the brain involved in learning and memory. The findings seem to support a physical, neurological component to PTSD.

Small hippocampi and PTSD have been linked in the past, but it has been difficult to disentangle cause and effect, according to BYU grad student and lead author Martin Woon.

"The big question about which came first, much like the chicken and the egg, has persisted... We found children’s hippocampi were intact after the onset of abuse, but somehow there was shrinkage in the group that had reached adulthood."

The study appeared in the August issue of the neuroscience journal Hippocampus.

The abstract and an article on the findings are available online.