More on the research work of Alain Brunet, PhD of Centre de Recherche, Douglas Hospital Research Center:

"Pitman examined identical twin brothers, one of whom served in Vietnam and the other who didn't. Among the veterans he studied, some suffer from chronic PTSD. Pitman found that Vietnam veterans with PTSD had a smaller hippocampus than did those without PTSD. Interestingly, so did their identical twin that had NOT been to Vietnam. In other words, given that we would expect identical twins to share similar physiology, it appears that the co-twin went to Vietnam with a smaller hippocampus in the first place."

I look forward to the study below being published, though I wonder if Dr. Brunet is looking at the effects of stress on the brain, or PTSD in particular?

"Through the use of MRI, they are following a group of trauma-exposed individuals over a period of one year and looking to see whether the size of the hippocampus changes over time. If the work of colleague Roger K. Pitman, MD, of the Harvard Medical School is of any indication, Brunet’s elegant studies will surely help disentangle a rather complex field."

High levels of stress often has a person asking themselves the following questions.

"Am I going crazy? Why do I get so angry over the slightest thing. I didn't used to be like that?"