Following previous research showing that having a smaller hippocampus is associated with increased risk of PTSD, a study involving 40 participants with PTSD and 36 trauma-exposed healthy controls has found that those PTSD patients who responded to the treatment had larger hippocampi compared to those who didn’t benefit from the therapy.
The participants were evaluated at baseline and after 10 weeks, during which time the PTSD group had prolonged exposure therapy.
The study found that both the resilient controls and the 23 patients with PTSD who responded to treatment had greater hippocampal volume at the beginning of the study than the 17 non-responders.
The findings add to growing evidence that the hippocampus is key to distinguishing between cues that signal safety and those that signal threat.
 . Greater hippocampal volume is associated with PTSD treatment response. Psychiatry Research: Neuroimaging [Internet]. 2016 ;252:36 - 39. Available from: http://www.sciencedirect.com/science/article/pii/S0925492715301451