Screening military personnel when they return from conflict zones fails to reduce mental health disorders or increase the numbers seeking help, a new study suggests.
A personalised screening service was no more effective than the standard general mental health advice for the British military, a medical journal found.
Instead, other approaches to encourage personnel with mental health disorders to seek help will be needed, the study by 'The Lancet' concludes.
Screening has been suggested as a way to identify those at risk of mental health problems on return from deployment and prompt them to seek help.
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In the study, led by the King's Centre for Military Health Research at King's College London, 10,190 UK military personnel completed a computerised mental health assessment on return from deployment.
Some were then offered the opportunity to view tailored advice, based on their likelihood of having a mental health disorder.
If they agreed, they were told what mental health issue they probably had and were urged to seek help by speaking either to a unit welfare officer for moderate symptoms, or a medical officer for more severe symptoms.
If no risk was identified, they were told that no professional support was needed.
Two-thirds (65%) agreed to seek advice, with higher-ranking and older personnel more likely to accept.
Other personnel were given the general mental health advice offered in the UK military.
All participants were then followed up between 10 and 24 months later.
The researchers found that there were no significant differences between the two groups in terms of the prevalence of post-traumatic stress disorder (11%), depression or anxiety (6%) and alcohol abuse (12%).
They found that 12% of personnel in the screening group used a mental health service in the follow-up period, compared with 13% in the control group. Lead author Professor Roberto Rona, from King's College London, said:
"Different countries use different approaches to post-deployment screening and our study looked at one particular type of screening, as it was the form that was most likely to be introduced in the UK military. We found no evidence to support the idea that post-deployment screening via a computerised assessment followed by tailored mental health advice helped improve the mental health of personnel over and above general mental health advice".
Professor Rona also said that countries that have already introduced post-deployment screening are currently unable to assess its effectiveness via a randomised controlled trial as they cannot generate a no-screening group.
She added, however, that they should consider monitoring the outcomes of their programmes.
Co-author Professor Neil Greenberg, from King's College London, said:
"Understandably, military forces are keen to protect the mental health of their personnel who carry out highly challenging duties on behalf of their countries. The question is what can be done to make a positive difference by protecting the mental health of personnel and decreasing the burden of mental illness on individuals, their families and UK society as a whole".
"More research is needed to improve the mental health of UK Armed Forces personnel and other approaches could include good leadership training, peer and family support programmes and further improving the quality and accessibility of military mental health services".
An MoD spokesman said: "We don't use post-operational mental health screening and regularly review how we manage the mental health of our armed forces. Currently, we use an effective combination of other initiatives ranging from prevention to treatment to help protect our people."