The Journal of Pediatric Psychology published a study that found kids with symptoms of post-traumatic stress demonstrated impaired function in their hippocampus, a part of the brain involved in memory. The study was the first of its kind to use MRIs — functional magnetic resonance imaging – to examine children’s brains, and the findings were consistent with harm seen in the hippocampus of adults in other studies on post-traumatic stress.
The study compared the brains of 16 young people, between 10 and 17 years old, who had symptoms of post-traumatic stress, with scans of 11 kids with no symptoms. The participants completed a verbal memory test while in the MRI machine. The post-traumatic stress group showed lower activity in their hippocampus and performed worse on the test.
One of the theories of post-traumatic stress is that the hippocampus actually shrinks to aid in forgetting the difficult memories, and that this response leaves the brain less able to store and retrieve regular memories as well.
While the study did not prove a causal link between post-traumatic stress and brain damage, only a correlation, the study’s authors believe the abnormal hippocampus is a result of post-traumatic stress. The study also found that the worse the hippocampus impairment, the more likely the youth was to demonstrate typical symptoms of post-traumatic stress disorder (PTSD), such as feeling isolated, not displaying emotion, and having trouble remembering the traumatic event.
PTSD is a condition that develops in response to a harrowing event, with symptoms typically starting within three months of the event. In addition to avoidance and numbing symptoms of PTSD, other common symptoms involve intrusive memories and heightened anxiety. The researchers hope that if there is enough convincing evidence linking hippocampus damage to PTSD, treatment could be targeted with drugs that impact that part of the brain.