PTSD Not Most Common Disorder That Develops After Trauma

An Australian study reaches some surprising conclusions about the association of brain injury and psychiatric disorders that follow a traumatic accident.

A large Australian study adds weight to the view that depression and anxiety are more likely psychiatric outcomes than posttraumatic stress disorder (PTSD) in the year following trauma.

The researchers also reported that patients with psychiatric disorders assessed at 12 months had more functional impairment, regardless of whether they had sustained a mild traumatic brain injury (TBI), and that mild TBI alone did not lead to greater functional impairment.

Overall, 23 percent of the 817 patients studied developed a new psychiatric disorder by the time of a 12-month assessment, wrote Richard Bryant, Ph.D., of the School of Psychology at Australia's University of New South Wales, and colleagues in the March American Journal of Psychiatry.

"A novel finding was that PTSD was not the most prevalent psychiatric disorder after traumatic injury, and when PTSD did occur, it typically occurred in the presence of another disorder," they said.

Initially, the researchers assessed 1,084 patients while in the hospital and assessed 817 at 12 months. Most were hurt in auto accidents, but some were victims of assault or traumatic falls. There was no non-trauma-exposed control group.

Depression (9 percent), generalized anxiety disorder (9 percent), PTSD (6 percent), and agoraphobia (6 percent) were the most common new diagnoses. These rates were higher than those recorded in the general Australian population.

PTSD tended to co-occur with other psychiatric disorders. Only 9 percent of subjects with PTSD had no comorbid disorders.

"This finding challenges the notion that PTSD is always the primary psychiatric disorder after trauma," said Bryant and colleagues. "t appears that a broader range of disorders affect people after traumatic injury."

They also noted that prevalence rates of the psychiatric disorders affecting their subjects remained nearly the same at 12 months as they were at three months.

The researchers excluded from the study patients with moderate to severe traumatic brain injury.

Those with mild TBI developed PTSD, panic disorder, agoraphobia, or social phobia twice as often as those with no TBI. Major depression and generalized anxiety disorder were unrelated to mild TBI in their analysis.

Mild TBI alone did not raise the odds ratio for physical or psychological impairment, but the combination of mild TBI and either PTSD, depression, anxiety, or any psychiatric disorder did so significantly. Having any psychiatric disorder without mild TBI also raised the odds of impairment significantly.