Risk Factors for the Development of Posttraumatic Stress Disorder Following Combat Trauma: A Semiprospective Study

Objective: When positioned in a combat situation, soldiers may be subjected to extreme stress. However, only a few combat-exposed soldiers develop long-term disturbance, namely, posttraumatic stress disorder (PTSD). This study aimed to explore risk factors for developing PTSD in order to improve the psychiatric screening process of new recruits.

Method: In a semiprospective design, we compared 2,362 war veterans who developed PTSD (according to DSM-IV criteria) with an equal number of war veterans who did not develop PTSD. Controls were matched on the basis of sequential army identification numbers, that is, the soldier drafted immediately after the index PTSD veteran (usually on the same day). This method ensured similar demographic variables such as socioeconomic level and education. Data were collected from the Israeli Defense Force database and used in a comprehensive survey conducted between January 2000 and March 2001. Comparisons were made on predrafting personal factors (behavioral assessment, cognitive assessment, linguistic ability, and education) and pretrauma army characteristics (ie, rank and training).

Results: Neither behavioral assessment nor training were found to predict PTSD. The predictive factors that were found were essentially nonspecific, such as cognitive functioning, education, rank, and position during the trauma, with little effect from training.

Conclusions: In an armed force that uses universal recruitment, carefully structured predrafting psychological assessment of social and individual qualifications (including motivation) failed to identify increased risk factors for PTSD. However, nonspecific factors were found to be associated with an increased risk for PTSD. This study suggests that the focus of future research on risk factors for PTSD should incorporate other domains rather than behavioral assessment alone.

Trial Registration: clinicaltrials.gov Identifier: NCT00229359

Submitted: January 13, 2008; accepted November 10, 2008.

Online ahead of print: October 20, 2009.

Corresponding author: Joseph Zohar, MD, Department of Psychiatry, Chaim Sheba Medical Center, Tel Hashomer 52621, Israel (Jzohar@post.tau.ac.il).