Over 30 percent of injury survivors who are treated in hospital emergency departments will have moderate-to-severe symptoms of posttraumatic stress disorder (PTSD) at some point in the first year following the initial incident, new research led by the Yale School of Public Health finds.
Assistant Professor Sarah Lowe, Ph.D., and colleagues pooled data from more than 3,000 people who were treated in emergency rooms in six countries: Australia, Israel, Japan, the Netherlands, Switzerland and the United States.
The study, published in the journal Psychological Medicine, examined PTSD symptoms over time and found that 64.5 percent of participants were resilient, exhibiting consistently low symptoms. The remaining 35.6 percent, however, fell into one of four other patterns, including initially high PTSD symptoms that decreased over time (16.9 percent), moderate symptoms (6.7 percent), delayed symptoms (5.5 percent) and chronically high symptoms (6.5 percent).
Factors associated with high PTSD symptoms were also identified in the study. Injuries that were due to physical assault, versus other causes, were shown to be especially predictive of immediate and longer-term symptoms over the first year. Survivors who had a history of interpersonal violence, including physical abuse and sexual assault, were also at greater risk.
Higher educational attainment was associated with fewer PTSD symptoms, the study found.
"By looking at PTSD symptom patterns across different contexts, we can have greater confidence in predicting which patients are likely to need short- and long-term mental health services," said Lowe, a member of the Department of Social and Behavioral Sciences. "Combining data from six countries was a major undertaking, but certainly worth the effort."
PTSD is characterized by a constellation of distressing symptoms, including nightmares, avoidance of reminders of the traumatic event, anger and irritability and an exaggerated startle response. The disorder is associated with increased risk for a variety of other negative consequences, including poor physical health, strained social relationships and disruptions in education and employment.
Lowe conducted the study with collaborators from the International Consortium to Predict PTSD, a large-scale effort to better understand the factors contributing to PTSD after a traumatic injury.
While the study is the first to examine PTSD symptom trajectories with pooled data, Lowe and colleagues hope that their work inspires researchers in other trauma exposed populations, including sexual assault and disaster survivors, to do the same.
The study was supported with a grant from the National Institutes of Health.