Clinicians have searched with mixed success for interventions that are useful shortly after trauma occurs to prevent later development of posttraumatic stress disorder (PTSD).
Now Emory University researchers add to that complex record with a study of the effects of prolonged exposure therapy in the emergency department on trauma survivors. They found that the intervention helped some trauma survivors but not others.
“Exposure therapy has received more empirical support than any other intervention for ASD [acute stress disorder] and PTSD but has never been attempted within hours of the traumatic event,” wrote Barbara Rothbaum, Ph.D., a professor in the Department of Psychiatry and Behavioral Sciences and director of the Trauma and Anxiety Recovery Program at Emory University School of Medicine, and colleagues in the December 1, 2012, Biological Psychiatry.
The study’s outcomes are encouraging but still leave unanswered the question of how—or if—PTSD can be prevented by some action in the emergency department, said Arieh Shalev, M.D., a professor of psychiatry at Hadassah Medical Center in Jerusalem, Israel, and a visiting professor at New York University. Shalev, a PTSD expert, was not involved with the Emory study.
The 137 participants were randomized to receive three one-hour sessions of a modified prolonged exposure intervention. The first session took place during the initial visit to the emergency room, within 12 hours of the trauma, on average. The other sessions were held one and two weeks later. Procedures included imaginal exposure and processing, guided by a trained therapist, as well as homework. Blinded assessors used several methods to evaluate symptoms of PTSD at four and 12 weeks and depression at four weeks.
“[T]he modified prolonged exposure intervention presented here may be able to prevent the development of PTSD . . . by encouraging engagement with the trauma memory and providing an opportunity for fear habituation and processing of unhelpful cognitions, thus modifying the memory before it is consolidated,” wrote Rothbaum.
Studies by other researchers indicate that early extinction training may prevent the effects of traumatic fear memories, she noted.
The differences in PTSD symptoms between the intervention and control groups were significant at week 4 for accident victims and for victims of sexual assault at both weeks 4 and 12. However, differences in PTSD severity at weeks 4 and 12 were not significant for patients who experienced physical assault or at week 12 for those who survived road accidents.
Other work based on the fear-conditioning model of PTSD has tested early interventions with treatments ranging from cognitive-behavioral therapy to propranolol, SSRIs, or cortisol to prevent the consolidation of memory, said Shalev, in an interview with Psychiatric News. However, no one has found the emergency-department key to preventing PTSD.
Complicating theory and practice in responding to trauma may be that trauma survivors who come to the emergency department may still be in the midst of the trauma, said Shalev.
“Some may still be within the trauma experience,” he explained. “They may be upset, can’t concentrate, feel out of control, have financial distress, or be facing surgery.”
The presence of one or more of these factors means that prolonged exposure therapy at that stressful moment may work for some people but not for others. More needs to be done to understand what drives early responses to trauma, he said.
Also, it is difficult to sort out early on who will or won’t develop PTSD. In the Emory study, many trauma survivors who were eligible for the study intervention chose not to participate, a finding similar to that observed by Shalev in a study he conducted in Jerusalem several years ago (Psychiatric News, November 18, 2011).
“There is a total overlap in the experience of people who go on to develop PTSD and those who don’t,” said Shalev. “Most people expect things to improve, and 85 percent of them do improve. But we are not able to tell in the first hours who is at the highest risk.”
If some treatment were truly effective during the consolidation window—about six to eight hours after the trauma—then additional treatment would not be necessary, he suggested.
More research is needed into this aspect of trauma care, Rothbaum and colleagues agree, “particularly to determine who requires early intervention and who will recover naturally without using valuable resources unnecessarily, what is the optimal window for intervention, how many sessions are needed, and what types of treatment are needed for what patients.” ■