Post-traumatic stress disorder
(PTSD) affects as many as 1 in 5 of all Americans who survive a harrowing experience like rape,
assault, war or terrorism. It has emotionally paralyzed survivors of 9/11 and broken up survivors' families. There is no broadly
accepted treatment that can lower the chance of developing the disorder, but thanks to a Tel Aviv University researcher, a
medical means of preventing PTSD may be just around the corner.
Prof. Joseph Zohar from the
Sackler Medical School, Tel Aviv University, has found that an injection of cortisol shortly after exposure to a traumatic
event may prevent the onset of PTSD. He is now taking his animal model findings to the U.S. National Institute of Health and hopes to start clinical trials on
this exploratory research within the next year.
The research was recently
published in the journal Biological Psychiatry.
PTSD Can Strike "Anyone, Anytime"
Currently, a diagnosis of
PTSD is made only after an individual has been living with an acute stress reaction for one month. By then it may be too late
to counteract the syndrome.
"10 to 20% of all individuals exposed to trauma develop PTSD," says Prof. Zohar. "The challenge is to try to prevent or reduce these numbers. Until now, the clinical and research focus
has been on treating PTSD once it developed. We propose to shift the focus to prevention. Based on an animal model, our new clinical findings pave
the way for a potential preventive treatment for future victims via cortisol injections."
Although experienced widely
among soldiers returning home from Iraq and Afghanistan, PTSD can strike anyone - anytime - who has witnessed or experienced a life-threatening event. Its victims dissociate from
loved ones and may relive the traumatic event through everyday triggers, such as the smell of a neighbor's barbecue or a sound
on TV.
Normally, the production of
cortisol, a stress hormone, increases immediately after the trauma, but with time returns
to normal levels. In those who are diagnosed with PTSD, however, the body's hormonal system is dysfunctional: there is less secretion of cortisol after exposure, and researchers
believe that this underproduction increases vulnerability to PTSD. Researchers propose that cortisol might be linked to the individual's ability to forget memories of the traumatic event.
The Persistence of Memory
Researchers from both Tel
Aviv University and Ben Gurion University, found in an animal model that a high dose of corticosterone, when given immediately
after the stress event, reduces the effect of trauma in mice. They believe that corticosterone may dampen an animal's ability
to "remember" the initial trauma time and time again.
The "stressor" in the mouse
experiment was litter soaked in cat urine. 25% of the mice presented with the litter showed signs of extreme stress, which
the researchers correlated to acute stress reaction in humans. Mice that were given shots of corticosterone shortly after
their exposure were significantly less "tense" when reminded of the initial trauma by the presentation of a "stressor reminder"
stimulus.
The researchers' next step
is to try this potential treatment option on humans in a controlled clinical setting. "The animal model we developed has given
us the basis for investigating this important condition, and it has become an essential tool for clinicians around the globe,"
adds Prof. Zohar, an internationally recognized expert in the field of PTSD and obsessive-compulsive disorders. He has established important international organizations in these fields and advises
institutions like the World Health Organization.
