Unit cohesion and mental health in the UK armed forces.

BACKGROUND Unit cohesion is recognized as a potentially modifiable factor in the aetiology of mental illness among military personnel. AIMS To examine the association between unit cohesion and probable post-traumatic stress disorder (PTSD), common mental disorder and alcohol misuse, in UK armed forces personnel deployed to Iraq. METHODS A sample of 4901 male UK armed forces personnel who had deployed to Iraq was drawn from a cohort of personnel who participated in a cross-sectional postal questionnaire study between June 2004 and March 2006. Information was collected on socio-demographic and military characteristics, deployment experiences and information on current health. RESULTS Perceived interest from seniors was associated with less probable PTSD [odds ratio (OR) 0.42, 95% confidence interval (CI) 0.26-0.67] and common mental disorder (OR 0.68, 95% CI 0.53-0.87). Among regular personnel, feeling well informed was associated with less common mental disorder (OR 0.74, 95% CI 0.58-0.95) and comradeship was associated with greater alcohol misuse (OR 1.98, 95% CI 1.19-3.28). Feeling able to talk about personal problems was associated with less alcohol misuse among reserve personnel (OR 0.31, 95% CI 0.16-0.60). The general construct of unit cohesion was predictive of less probable PTSD (OR 0.69, 95% CI 0.58-0.81) and common mental disorder (OR 0.80, 95% CI 0.73-0.87). CONCLUSIONS Unit cohesion had a linear association with less probable PTSD and common mental disorder. Of the individual items, perception of leadership was associated with less probable PTSD and common mental disorder. Comradeship was associated with greater alcohol misuse among regular personnel, while feeling able to talk about personal problems was associated with less alcohol misuse for reserve personnel.