Mild traumatic brain injury in UK military personnel returning from Afghanistan and Iraq: cohort and cross-sectional analyses.

OBJECTIVES: : To assess (a) the prevalence of mild traumatic brain injury (mTBI) in UK military personnel deployed to Iraq and/or Afghanistan, (b) the risk factors associated with mTBI, and (c) the association between mTBI and subsequent postconcussion symptoms (PCS). PARTICIPANTS: : A total of 4620 personnel deployed to Iraq and/or Afghanistan who completed a questionnaire between 2007 and 2009, of whom 2333 were also studied in 2005, participated in the study. MAIN OUTCOME MEASURES: : Mild traumatic brain injury during deployment, as identified using a modified version of the Brief Traumatic Brain Injury Screen questionnaire; symptoms associated with PCS in the month before questionnaire completion. RESULTS: : The prevalence of mTBI was 4.4%, and the prevalence in those with a combat role was 9.5%. Having an mTBI was associated with current symptoms of posttraumatic stress disorder (adjusted odds ratio (AOR), 5.2; 95% confidence interval [CI], 2.3-11.4), alcohol misuse (AOR, 2.3; 95% CI, 1.4-3.7), and multiple physical symptoms (AOR, 2.6; 95% CI, 1.3-5.2). Only 3 of 9 symptoms remained associated with mTBI after adjustment. Psychological distress and alcohol misuse recorded before deployment were associated with subsequent mTBI. CONCLUSIONS: : The prevalence of mTBI in UK military is lower than that in the US military. Symptoms of current posttraumatic stress disorder and alcohol misuse are associated with mTBI. Symptoms of mental disorder predated occurrence of mTBI. The majority PCS were not associated with mTBI.

What are the consequences of deployment to Iraq and Afghanistan on the mental health of the UK armed forces? A cohort study.

BACKGROUND: Concerns have been raised about the psychological effect of continued combat exposure and of repeated deployments. We examined the consequences of deployment to Iraq and Afghanistan on the mental health of UK armed forces from 2003 to 2009, the effect of multiple deployments, and time since return from deployment. METHODS: We reassessed the prevalence of probable mental disorders in participants of our previous study (2003-05). We also studied two new randomly chosen samples: those with recent deployment to Afghanistan, and those who had joined the UK armed forces since April, 2003, to ensure that the final sample continued to be representative of the UK armed forces. Between November, 2007, and September, 2009, participants completed a questionnaire about their deployment experiences and health outcomes. FINDINGS: 9990 (56%) participants completed the study questionnaire (8278 regulars, 1712 reservists). The prevalence of probable post-traumatic stress disorder was 4.0% (95% CI 3.5-4.5; n=376), 19.7% (18.7-20.6; n=1908) for symptoms of common mental disorders, and 13.0% (12.2-13.8; n=1323) for alcohol misuse. Deployment to Iraq or Afghanistan was significantly associated with alcohol misuse for regulars (odds ratio 1.22, 95% CI 1.02-1.46) and with probable post-traumatic stress disorder for reservists (2.83, 1.23-6.51). Regular personnel in combat roles were more likely than were those in support roles to report probable post-traumatic stress disorder (1.87, 1.26-2.78). There was no association with number of deployments for any outcome. There was some evidence for a small increase in the reporting of probable post-traumatic stress disorder with time since return from deployment in regulars (1.13, 1.03-1.24). INTERPRETATION: Symptoms of common mental disorders and alcohol misuse remain the most frequently reported mental disorders in UK armed forces personnel, whereas the prevalence of probable post-traumatic stress disorder was low. These findings show the importance of continued health surveillance of UK military personnel. FUNDING: UK Ministry of Defence.