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Protecting the wellbeing of UK armed forces

Our research into the mental health consequences of deployment helped secure a pay increase for members of the UK’s armed forces and influenced a top-level military decision not to extend the length of operational tours.

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The UK military’s Harmony Guidelines stipulate the duration of tours of duty. They differ for each of the armed services, and are designed to safeguard against excessive deployments and overstretch.

For the army, the guidelines state that a tour should last for six months and be followed by a 24-month break. Therefore, if the guideline is followed, a unit should not be deployed for more than 12 months within a three-year period.

Research led by Professor Roberto Rona at King’s Centre for Military Health Research (KCMHR), showed that when servicemen and women had been deployed for more than 13 months within three years, they were more likely to report mental ill health as well as symptoms of physical ill health and problems at home.

Unforeseen increases in the length of a tour were especially detrimental: if the tour of duty was longer than anticipated, servicemen and women were much more likely to report symptoms of post-traumatic stress disorder (PTSD) afterwards.

The number of tours, however, made no difference to people’s psychological wellbeing. ‘The length of each tour and the “down-time” in between was more important than the actual number of deployments,’ says Professor Sir Simon Wessely, co-director of KCMHR.

‘Our research highlighted the importance of adherence to the Harmony Guidelines covering tour length,’ he says. ‘The guidelines weren’t often broken, but if they were, there was an effect on people’s mental health.’

The research team also showed that whilst ‘Regulars’ were not at increased risk of mental health problems following deployment, the ‘Reserve’ personnel were. This led to a specific programme of mental health support within the NHS for Reserves.

Our research was cited in the 2008 Armed Forces’ Pay Review Body report that recommended a one per cent increase to service wages. The risk of developing mental health problems – particularly when the Harmony Guidelines are breached – was one of the reasons for the increase.

In 2011, the UK Armed Forces were asked to review their policy on tour length, partly for financial reasons. The Chief of the Defence Staff and Chief of the General Staff set up a committee to consider proposals for increasing tour length from six to nine months.

‘We gave evidence to the committee, as our work was the only source of UK data on the impact of tour length on mental health. We later learned that one reason the committee did not recommend a change of policy on tour length was because it accepted our views that increasing the tour length might have a negative impact on mental health,’ says Professor Wessely.

KCMHR figures suggest that, for each year of continued operations in Iraq and Afghanistan, adherence to the Harmony Guidelines prevents an additional 7.1 per cent of common mental illnesses and post-traumatic stress disorder, and 7.7 per cent of alcohol problems.

The research was carried out as part of an ongoing ‘Health and Wellbeing of UK Armed Forces’ study at KCMHR, which been running since 2003, and includes approximately 16,000 service men and women.

Research led by Professors Simon Wessely & Roberto Rona

Download a PDF of the information on this page >


• Rona RJ. et al. Mental health consequences of overstretch in the UK armed forces: first phase of a cohort study. BMJ, 2007 Sept 22; 335(7620): 603

• Armed Forces’ Pay Review Body, 37th Report, February 2008

• Fear N. et al. What are the consequences of deployment to Iraq and Afghanistan on the mental health of the UK Armed Forces? A cohort study. The Lancet, 2010; 375: 1783-1797

• Hotopf M. et al. The health of UK military personnel who deployed to the 2003 Iraq war: a cohort study. The Lancet, 2006; 367(9524): 731-41

• Harvey SM. et al. The long-term consequences of military deployment: a 5-year cohort study of United Kingdom Reservists deployed to Iraq in 2003. Am J Epidemiol, 2012; 176: 1177-84

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