Results of a study confirm that young adults who develop posttraumatic stress disorder (PTSD) after traumatic events are at increased risk of attempting suicide later on. Importantly, the researchers say, the study also shows that people who experience a traumatic event but do not develop PTSD are not at increased risk of attempting suicide.

"It is not trauma but PTSD that is an independent predictor of subsequent suicide attempt," Dr. Holly C. Wilcox told Reuters Health.

Wilcox of Johns Hopkins University School of Medicine, Baltimore, Maryland and her colleagues examined the association between exposure to traumatic events — with and without the development of PTSD — and the risk of subsequent suicide attempt.

Among 1,698 young adults interviewed at an average age of 21 years, 1,273 (75 percent) had been exposed to a traumatic event, but only 100 (8 percent of those exposed to trauma) developed PTSD.

According to the team's report in Archives of General Psychiatry, 10 percent of individuals with PTSD had attempted suicide, compared with just 2 percent of individuals who were exposed to trauma but did not develop PTSD and 5 percent of those who had never been exposed to traumatic events.

The researchers calculate that trauma-exposed young adults who developed PTSD had a 2.7-fold increased risk of a later suicide attempt, after accounting for established risk factors for attempted suicide such as depression and alcohol or drug abuse.

In contrast, "persons who had been exposed to traumatic events, including traumatic events of high magnitude that involve assaultive violence, who did not develop PTSD were not at increased risk of suicide attempt," Wilcox told Reuters Health.

Prior studies, the researchers note, have found that up to 20 percent of suicide attempts in young people are due to sexual abuse suffered in childhood. "Although we did not focus explicitly on child sexual abuse, our results point to the need to base risk estimates of attempted suicide on data that take into account the psychiatric response to the trauma," they write.