Summary (for full article, see link above)
“Few studies have examined suicide risk in individuals once they have left the military. We aimed to investigate the rate, timing, and risk factors for suicide in all those who had left the UK Armed Forces (1996–2005).”
“We carried out a cohort study of ex-Armed Forces personnel by linking national databases of discharged personnel and suicide deaths (which included deaths receiving either a suicide or undetermined verdict). Comparisons were made with both general and serving populations.”
“Although the overall rate of suicide was not greater than that in the general population, the risk of suicide in men aged 24 y and younger who had left the Armed Forces was approximately two to three times higher than the risk for the same age groups in the general and serving populations. … The rate of contact with specialist mental health was lowest in the age groups at greatest risk of suicide.”
Veterans For Peace UK 
A very valuable and timely study, giving factual backing to the need for much greater care and attention to be given to ex-service personnel by the state they have served.