Combat Experiences and their Relationship to Post-Traumatic Stress Disorder Symptom Clusters in UK Military Personnel Deployed to Afghanistan.

The association of post-traumatic stress disorder (PTSD) symptom clusters with combat and other operational experiences among United Kingdom Armed Forces (UK AF) personnel who deployed to Afghanistan in 2009 were examined. Previous studies suggest that the risk of developing PTSD rises as combat exposure levels increase. To date, no UK research has investigated how specific classes of combat and operational experiences relate to PTSD symptom clusters. The current study was a secondary analysis of data derived from a two-arm cluster, randomized-controlled trial of a postdeployment operational stress-reduction intervention in deployed UK AF personnel. 2510 UK AF personnel provided combat exposure data and completed the PTSD checklist (civilian version) immediately post-deployment while 1635 of the original cohort completed further followed-up measures four to six months later. A 14-item combat experience scale was explored using principle component analysis, which yielded three main categories of experience: (1) violent combat, (2) proximity to wounding or death and (3) encountering explosive devices. The association of combat experience classes to PTSD 5-factor "dysphoric arousal" model (re-experiencing, avoidance, numbing, dysphoric-arousal and anxious-arousal symptoms) was assessed. Greater exposure to violent combat was predictive of re-experiencing and numbing symptoms, while proximity to wounding or death experiences were predictive of re-experiencing and anxious-arousal symptoms. Explosive device exposure was predictive of anxious-arousal symptoms. The present study suggests that categories of combat experience differentially impact on PTSD symptom clusters and may have relevance for clinicians treating military personnel following deployment.