Can acute stress disorder (ASD) predict posttraumatic stress disorder
(PTSD)? Small studies have produced conflicting results. Now results of a
larger study, conducted by Australian researchers, has sided with researchers
who have found no predictive link.
It was headed by Richard Bryant, Ph.D., of the University of New South
Wales. Results were published in the June Journal of Clinical
Psychiatry.
Some 500 civilians admitted to four major trauma hospitals across Australia
between April 2004 and April 2005 served as subjects in this study. Sixty-two
percent had been admitted because of injury due to a motor-vehicle accident,
16 percent had been admitted because of injury due to a fall, 8 percent had
been admitted because of injury due to an industrial accident, 5 percent had
been admitted because of injury due to an assault, and the remaining 9 percent
had been admitted for other reasons.
Within a month after the subjects' hospitalization, Bryant and his
coworkers used DSM-IV criteria to determine how many of them were
experiencing ASD. Thirty-three (6 percent) were. Three months later, Bryant
and his coworkers used DSM-IV criteria to determine how many of them
had PTSD. Forty-nine (10 percent) did. Bryant and his group then looked to see
how many of the 49 patients who met PTSD criteria at the three-month follow-up
assessment had had ASD within the month after their trauma. They found that 15
(31 percent) had.
Thus, "The majority of people who develop PTSD do not initially meet
criteria for ASD," Bryant and his team concluded. "These data
challenge the proposition that the ASD diagnosis is an adequate tool to
predict chronic PTSD."
Nonetheless, Bryant and his coworkers did find that ASD's prognostic power
tended to be somewhat stronger for subjects who had experienced a brain injury
in conjunction with their trauma than for those who had not. Specifically, ASD
predicted PTSD in 58 percent of this sub-group of subjects, versus 31 percent
for the entire subject group. This particular finding may have relevance for
the many Iraq War veterans whose PTSD is coupled with traumatic brain injury
(Psychiatric News, March 2, 2007).
Also, since most of the subjects had been traumatized by accidental
injuries, ASD might be more predictive of PTSD in patients whose trauma arises
from other physical causes—say, from physical assault, sexual assault,
or military combat—Bryant and his colleagues noted. Still, the rates of
ASD and PTSD that they found in their subjects are similar to those that have
been found in some other trauma populations, they pointed out. So their
findings can probably be generalized to all trauma populations, they
reasoned.
All told, since an ASD diagnosis appears to have only a limited ability to
foretell PTSD, at least in persons who have been traumatized by accidental
injuries, better tools than an ASD diagnosis are needed to determine which
trauma victims are going to develop PTSD, Bryant and his group stated. For
instance, preliminary evidence suggests that trauma patients' heart rates or
moods in the wake of trauma might be good bellwethers of subsequent PTSD, they
said.
The study was funded by Australia's National Health and Medical Research
Council.
An abstract of "A Multisite Study of the Capacity of Acute
Stress Disorder Diagnosis to Predict Posttraumatic Stress Disorder" is
posted at<www.psychiatrist.com/abstracts/abstracts.asp?abstract=200806/060806.htm>.▪