Study Finds PTSD Results in Decreased Brain Volume

Post-traumatic stress disorder (PTSD) is a condition that may follow the experience or the witnessing of a stressful event. It can result from any tragic situation, from witnessing an assault to becoming injured in a vehicle accident.

The symptoms of PTSD can range from relatively mild to severely limiting. Symptoms include anxiety and depression, as well as insomnia and flashbacks, among others. For some who experience the disorder, normal daily life is impossible as they struggle to cope with the recurring stress that results from violent dreams.

A recent study has found that there are significant brain alterations that are associated with a diagnosis of PTSD. Researchers at Duke University and the Durham VA Medical Center discovered that soldiers returning from deployment to combat zones have a measurably lower volume in the amygdala, an area of the brain responsible for fear and anxiety.

The findings are consistent, say the researchers, no matter how severe the trauma experienced. However, the team notes that the study’s findings do not provide information about whether the decreased volume is caused by the trauma or if those with a smaller amygdale may be more susceptible to the development of PTSD.

Lead author of the study, Rajendra A. Morey, M.D., M.S., assistant professor at Duke, explains that previous research had identified volume change in the hippocampus that was found to be associated with PTSD. The new findings provide information more relevant to the disorder, because the amygdala is central to the symptoms associated with PTSD.

Morey also reports that the new finding is important because while the role of the amygdala has been widely examined in its responsibility for regulating fear, stress and anxiety, it has been less explored in humans. He notes, though, that because the amygdala has long been understood to be critical in processing fear, and particularly abnormal experiences of fear. Because of this, he believes that the findings make sense with what was previously known about this part of the brain.

To evaluate the association of PTSD with reduced brain volume in the amygdala, the research team examined 200 veterans returning from combat in Iraq or Afghanistan in the period since September 11, 2001. Half of the veterans had a diagnosis of PTSD, and the other veterans had experienced an exposure to trauma, but did not exhibit symptoms of PTSD. The researchers used MRIs to look at the hippocampus and amygdala volumes of all the participants.

The researchers discovered that PTSD was significantly associated with smaller volume in both left and right sections of the amygdala, and their findings provided additional support for previous research that found decreased volume in the hippocampus of those with PTSD.

The findings were consistent after controlling for factors such as substance abuse, depression and PTSD symptom severity.