Does PTSD affect the brain?

Q: Dear Frank, I read recently that prolonged and extreme fear or stress, including PTSD (especially prolonged) can cause damage to the brain. If it’s true, what part of the brain, and what are the consequences or symptoms? I know in children it can affect the frontal lobe development. But this article claimed even adults can be affected by brain damage.

A: Dear reader, Stress can damage the brain. Recent studies of combat vets with PTSD, compared to identical twins without stress, showed statistically significant brain-scan changes. There was a reduction of grey matter (nerve cell bodies) in a part of the brain known to connect thought centers and emotional centers. That part of the brain is called the anterior cingulate gyrus. But there have not been long term follow-up studies to see if the brain recovers those losses. We do know that PTSD is treatable and the symptoms usually improve.

This recent finding is interesting, because a similar twin study showed there was no reduction in the size of another brain part called the hippocampus. We know that a small hippocampus correlates with vulnerability to PTSD. The hippocampus is a switching station for memory.

The larger hippocampus seems better able to manage terrifying life events without generating the kind of trauma memory that bursts forth later as flashbacks and unwanted, piercing recollections. In this older study, the scientists looked at combat veterans, some of whom developed PTSD and some who did not. All the vets had identical twins who were not exposed to trauma. The vets with PTSD had smaller hippocampi than the vets without PTSD, but those PTSD vets had twins with smaller hippocampi.

These studies seem to say that a small hippocampus is a risk factor for PTSD, but PTSD is a risk factor for a reduced anterior cingulate gyrus.

Does brain anatomy affect stress-resilience? Yes.
Does stress affect brain anatomy? Yes.

Is the brain damage from stress permanent? We do not know. I doubt it, however. The brain is an organ with amazing recuperative powers. Unless it is very old or very damaged, the human brain forms new pathways, new cellular connections and new ways of responding to anatomical disruption.

Webcast: How Does PTSD Affect Brain Function?

Exposure to a traumatic event may cause PTSD symptoms. Stress can damage the brain. In this webcast, Dr. Frank Ochberg discusses what happens to the brain after a traumatic event.