Despite prolonged combat missions to Iraq and Afghanistan, there has been no overall increase in mental health problems among UK soldiers, finds a review of the available evidence, published online in the Journal of the Royal Army Medical Corps.
But certain groups of soldiers do seem to be more vulnerable to mental ill health on their return home, while alcohol problems continue to give cause for concern among regulars, say the researchers from King's College London.
They retrieved published research looking at the psychological impact of deployment to Iraq and Afghanistan on the UK Armed Forces, dating back 15 years. And where possible, they compared the research findings with those published on the mental health of US military personnel.
. The researchers focused on Iraq and Afghanistan because of the lengthy and challenging nature of the conflict experienced by British soldiers in these two countries, including protracted counter insurgency and repeated exposure to improvised explosive devices (IEDs), snipers, and suicide bombers.
Their analysis, which draws on 34 studies, shows that, overall, most UK regulars returning from deployment have remained psychologically resilient, despite the adversities they faced.
Rates of post-traumatic stress disorder, or PTSD, among most UK regulars returning from deployment range between 1.3% and 4.8%, the evidence suggests; the prevalence of PTSD among the UK general population is 3%, say the authors.
Not unexpectedly, troops involved in direct combat are more likely to experience mental health issues than their peers not deployed in this way.
The rate of PTSD among these soldiers is around 7%, the data indicate. But not all combat troops have the same level of risk: elite forces, such as the Royal Marines and airborne personnel report fewer mental health problems.
Combat troops are also twice as likely to experience mild traumatic brain injury (mTBI) - short term loss of consciousness or altered mental state following a head injury or blast explosion - as those not deployed in combat. But mTBI rates are consistently lower than among the US military and the rate of mTBI in combat remains very low indeed, say the authors.
Depression and anxiety are the most frequently reported common mental health disorders among soldiers who have served in Iraq and Afghanistan. But overall rates are no higher than among soldiers who have not been deployed to these regions - or indeed the general population, the research indicates.
Harmful drinking, however, continues to give cause for concern, affecting up to one in five regular soldiers, while aggressive and violent behaviour is also more likely among those returning from deployment, particularly soldiers in combat roles who are experiencing mental health issues.
But despite the unique stressors soldiers face, rates of suicide and self-harm are lower than they are among the general population, except for army recruits under the age of 20.
And the evidence suggests that levels of social support during childhood and after leaving the Army have a greater impact on suicide rates than deployment.
Overall, UK troops fare better than their US peers in terms of their mental health, possibly because UK Army recruits tend to be older, have shorter tours of duty, and have better access to healthcare, say the authors. But UK troops are more likely to report harmful levels of drinking than their US peers.
There is also some evidence to suggest that good training, leadership and unit cohesion may help to stave off mental health problems, in addition to which the Army has invested heavily in initiatives to mitigate the effects of trauma and ease soldiers' return home.
These include 'third location decompression'(TLD) - 36 hours of social, supportive, and educational intervention after prolonged operational deployment before returning home - and the Trauma Risk Management Programme (TRiM) - peer support designed to pick up vulnerability to mental health problems in the wake of a traumatic incident.
"The evidence presented [here] shows that, in the main, UK military personnel have remained resilient in spite of having suffered significant numbers of fatalities and casualties in Iraq and Afghanistan," write the authors.
They acknowledge that there will be "a small but important group of veterans" who will need specialist mental healthcare services in the years ahead, and that it is too early to tell what the longer term psychological impacts of service in Iraq and Afghanistan might be.
But they conclude: "There appears to be some evidence that the considerable efforts the UK Armed Forces have made to ensure that deployed personnel are well trained, well led, cohesive, have access to high quality mental health services and a number of evidence based mitigation measures, such as TLD and TRiM, are important."