Some Are More Susceptible to PTSD, Brain Study Suggests
New research suggests there may be structural differences in the brain that make some people more susceptible to developing post-traumatic stress disorder.
In a 2012 study, recently returned combat veterans with PTSD had smaller volumes in an area of the brain involved in fear and anxiety responses. This is the first study showing that smaller amygdala is associated PTSD, regardless of severity.
Researchers from Duke University and Durham VA Medical Center studied 200 combat veterans of the Iraq and Afghanistan Wars. While half of the veterans were diagnosed with PTSD, the other half had been exposed to trauma but did not develop the disorder.
Using MRI scans, the researchers analyzed the volumes of the amygdala and the hippocampus.
The researchers confirmed the results of earlier studies showing an association between smaller hippocampus volumes and PTSD. But they also discovered that veterans with PTSD had significantly smaller amygdala.
The next step was to determine whether smaller amygdala was a cause or consequence of trauma. The researchers found that smaller amygdala volume was not influenced by severity, frequency, or duration of trauma. This suggests that exposure to trauma did not cause the amygdala to become smaller, indicating that people with smaller amygdala may be more vulnerable to developing PTSD.
Although more research is needed to confirm these findings, the study bring us closer to understanding why certain people develop PTSD and others do not, lead researcher Dr. Rajendra A. Morey concluded.
Posttraumatic stress is common in auto-injury patients, and often lingers long after the collision. A recent study found that a year after the car crash, 46% of victims with severe injuries continued to suffer from post-traumatic stress that interfered with their daily life. Previous research has also shown that PTSD can lead to muscle degeneration and exacerbated symptoms whiplash patients. Understanding the biological mechanisms behind the disorder could lead to improved prevention and treatment outcomes.
Duke University Medical Center (2012, November 5). PTSD linked to smaller brain area regulating fear response. ScienceDaily.
Rajendra A. Morey et al. Amygdala Volume Changes in Posttraumatic Stress Disorder in a Large Case-Controlled Veterans Group. Arch Gen Psychiatry, 2012;69(11):1169-1178 DOI: 10.1001/archgenpsychiatry. 2012.50.