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Mental health consequences of overstretch in the UK armed forces: first phase of a cohort study

BMJ 2007; 335 doi: (Published 20 September 2007) Cite this as: BMJ 2007;335:603
  1. Roberto J Rona, professor of public health1,
  2. Nicola T Fear, senior lecturer in military epidemiology2,
  3. Lisa Hull, study coordinator1,
  4. Neil Greenberg, senior lecturer in military psychiatry2,
  5. Mark Earnshaw, research fellow2,
  6. Matthew Hotopf, professor of general hospital psychiatry1,
  7. Simon Wessely, professor of epidemiology and liaison psychiatry1
  1. 1King's College London, King's Centre for Military Health Research, Weston Education Centre, London SE5 9RJ
  2. 2Academic Centre for Defence Mental Health, Weston Education Centre
  1. Correspondence to: R J Rona roberto.rona{at}
  • Accepted 28 June 2007


Objective To assess the relation between frequency and duration of deployment of UK armed forces personnel on mental health.

Design First phase of a cohort study.

Setting UK armed forces personnel.

Participants Operational history in past three years of a randomly chosen stratified sample of 5547 regulars with experience of deployment.

Main outcome measures Psychological distress (general health questionnaire-12), caseness for post-traumatic stress disorder, physical symptoms, and alcohol use (alcohol use disorders identification test).

Results Personnel who were deployed for 13 months or more in the past three years were more likely to fulfil the criteria for post-traumatic stress disorder (odds ratio 1.55, 95% confidence interval 1.07 to 2.32), show caseness on the general health questionnaire (1.35, 1.10 to 1.63), and have multiple physical symptoms (1.49, 1.19 to 1.87). A significant association was found between duration of deployment and severe alcohol problems. Exposure to combat partly accounted for these associations. The associations between number of deployments in the past three years and mental disorders were less consistent than those related to duration of deployment. Post-traumatic stress disorder was also associated with a mismatch between expectations about the duration of deployment and the reality.

Conclusions A clear and explicit policy on the duration of each deployment of armed forces personnel may reduce the risk of post-traumatic stress disorder. An association was found between deployment for more than a year in the past three years and mental health that might be explained by exposure to combat.


  • We thank the UK Ministry of Defence for their cooperation; in particular we thank the Defence Medical Services Department, the Defence Analytical Services Agency, the Armed Forces Personnel Administration Agency, and the Veteran's Policy Unit.

  • Contributors: RJR planned and sought funding for the study, supervised data collection, designed analysis, and was the lead author in writing the paper. NTF was involved with the data collection, was responsible for the data processing, discussed and carried out the analysis, and wrote this paper. LH was responsible for the coordination of this study and was involved in the planning of the study and writing of the paper. ME was involved in the planning and writing of the paper. NG was involved in the planning and writing of the paper. MH sought funding and participated in the planning, supervision of data collection, and writing of the paper. SW sought funding for, and led the planning of, the study, supervised data collection, and made comments on the analysis and writing of the paper. All authors approved the final version. RJR and NTF are guarantors for the paper.

  • Funding: The study was funded by the UK Ministry of Defence. The work was independent of the funders but a copy of the paper was sent to them. The Defence Analytical Services Agency provided the sampling frames of the armed forces. We indicated our requirements to obtain random samples for the study and discussed feasibility and operational issues with the Defence Analytical Services Agency. The agency supplied addresses and identifiers directly related to personnel in the random samples and deployment allocation in relation to the Iraq war (Telic 1). The funders did not participate in data collection, data processing, data analysis, or interpretation of findings.

  • Competing interests: SW is honorary civilian consultant adviser to the British army. NG and ME are members of the Defence Medical Services seconded to King's College London. Although NG and ME are paid from Ministry of Defence funds they have not been directed in any way by the ministry in relation to this publication.

  • Ethical approval: This study was approved by the Ministry of Defence (Navy) personnel research ethics committee and the King's College Hospital local research ethics committee.

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