Posttraumatic Stress Disorder Heightens Suicide Risk
Allison Gandey

"The PTSD–suicide-attempt association was robust," write the authors, led by Holly Wilcox, PhD, from Johns Hopkins University, in Baltimore, Maryland. This was even after adjustment for a prior major depressive episode, alcohol abuse or dependence, and drug abuse or dependence.

"In contrast," they note, "exposure to traumatic events without PTSD was not associated with an increased risk of suicide."

The researchers studied nearly 1700 young adults from a group that has been followed since entering the first grade in Baltimore public schools. The sample is composed of predominately African Americans who grew up in an urban metropolitan area. The average age of the young adults is 21 years.

Investigators conducted interviews with participants to assess the occurrence of traumatic experiences, suicide attempts, and the development of PTSD.

Of those interviewed, 81% had been exposed to a traumatic event and 8% of those exposed to trauma developed PTSD. Dr. Wilcox and her team found that people exposed to trauma who developed PTSD were at an increased risk for attempted suicide. The adjusted relative risk was 2.7 (95% CI, 1.3 – 5.5; P < .01).

Rate of Attempted Suicide

Investigators also observed a more than 3-fold increase in the risk for attempted suicide among people with PTSD from assaultive violence compared with people who did not develop PTSD.

Previous research has found that up to 20% of suicide attempts in young people are attributable to sexual abuse during childhood, the authors note. "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.

"By distinguishing between trauma-exposed persons without and with PTSD, we found that it is PTSD that is associated with an increased risk of a suicide attempt. Whether or not this finding applies to sexual abuse in childhood or adulthood should be investigated in future studies."

The mechanisms involved in the association between PTSD and suicide attempts are not known, the researchers add. "There could be a common preexisting predisposition to PTSD and suicide attempts that was present before the trauma occurred. Studies of early trauma and suicidal behaviors have implicated depression and impulsivity as possible mediators or possible preexisting susceptibility traits."

This study was funded by the National Institute of Mental Health and the National Institute on Drug Abuse.