Objective To explore the psychological consequences of improvised explosive device (IED) exposure as IEDs have been the greatest threat to UK military personnel in Afghanistan though the mental health consequences of IED exposure are largely unknown.

Method Deployed UK military personnel completed a survey while deployed in Afghanistan. Combat personnel and those dealing specifically with the IED threat were compared with all other deployed personnel; the relationship between IED exposure, general combat experiences, Post Traumatic Stress Disorder (PTSD) Checklist-Civilian Version (PCL-C) and General Health Questionnaire scores were evaluated.

Results The response rate was 98% (n=2794). Half reported IED-related concerns, a third experienced exploding IEDs and a quarter gave medical aid to IED casualties. Combat and counter-IED threat personnel had higher levels of IED exposure than other deployed personnel. 18.8% of personnel who witnessed exploding IEDs scored positive for common mental disorder (General Health Questionnaire-12 scores ≥4) and 7.6% scored positive for probable PTSD symptoms (PTSD Checklist-Civilian Version scores ≥44). After adjusting for general combat exposure and other observed confounders, PTSD symptoms were associated with IED exposure whereas common mental disorder symptoms were not. IED exposure, IED-related concerns and functional impairment accumulated during deployment but functional impairment was related to factors other than IED exposure alone.

Conclusions In Afghanistan, a substantial proportion of personnel were exposed to exploding IEDs however, the majority of exposed personnel were psychologically healthy. Psychological effects were similar for combat personnel and those dealing specifically with the IED threat but both groups were at greater psychological risk than other deployed personnel.