A de-brief some time after returning from Iraq may be a better method to help this soldier deal with his experience.
Credit: iStockphoto
SYDNEY: Soldiers returning from war may be best to have counselling some time after coming home, rather than when they first step off the plane, if a new experiment with rats can be used as any guide.
Stephen Maren and Chun-Hui Chang from the University of Michigan in the USA performed an experiment in which they trained rats to be afraid of a sound by gently zapping their feet with an electric charge at the same time as the tone. They then tested the best way to remove this fear again, a process known as fear 'extinction'.
As Maren explained, "We use fear conditioning and extinction in rats to model in humans the learning that occurs during a traumatic event … For example, soldiers come to associate the sound of gunshots and concussive explosions with battle field carnage, and for some, the later experience of a loud sound [such as] fireworks or a car back firing, evokes the traumatic memory."
Early intervention, for example debriefing soldiers immediately after their tour of duty, is the prevailing wisdom for dealing psychologically difficult experiences. But Maren and Chang said their research suggests that waiting may be a better strategy.
In the study, which is published in the U.S. journal Proceedings of the National Academy of Sciences, Maren and Chang 'extinguished' the fear, either 15 minutes or one day later, by playing the tone in the absence of the electric shock.
They found that intervention a day after the fearful event was more successful in the long-term suppression of fear than intervening immediately afterwards.
Fear was diminished when the tone was played by itself only minutes after the tone-and-zap, but a day later, the rats were afraid of the tone again. However when the researchers waited a day before playing the tone by itself, they found it led to an enduring suppression of fear.
According to Maren and Chang, "These results show that the level of fear present at the time of intervention is a critical factor in the efficacy of extinction."
Fear was assessed by measuring the amount of time the rats showed 'freezing behaviour' - a standard psychological measure of fear in rats - where all movement aside from breathing ceases. Fear was considered to have been conquered when playing the tone by itself did not cause the rats suddenly to stand stock-still.
In addition, Maren and Chang showed that it was not the exact time after a traumatic event that intervention was most useful, but the level of fear prior to 'extinction' that was critical. In other words, intervention when fear levels were lower had more lasting effects.
So while early intervention may be appropriate for mild trauma, this research shows that cases of more serious trauma may benefit from treatment after an interval. "Indeed, for people who experience severe trauma, this interval may extend beyond days or even weeks," they said.
The authors said they believed the results of their study have implications not only for war veterans, but for the treatment of people who have suffered other traumatic events, such as motor vehicle accidents or sexual assault.
