Research Paper Title
Cognitive ability and risk of post-traumatic stress disorder after military deployment: an observational cohort study.
Studies of the association between pre-deployment cognitive ability and post-deployment post-traumatic stress disorder (PTSD) have shown mixed results.
The aim of the research was to study the influence of pre-deployment cognitive ability on PTSD symptoms 6-8 months post-deployment in a large population while controlling for pre-deployment education and deployment-related variables.
Study linking prospective pre-deployment conscription board data with post-deployment self-reported data in 9695 Danish Army personnel deployed to different war zones in 1997-2013. The association between pre-deployment cognitive ability and post-deployment PTSD was investigated using repeated-measure logistic regression models. Two models with cognitive ability score as the main exposure variable were created (model 1 and model 2). Model 1 was only adjusted for pre-deployment variables, while model 2 was adjusted for both pre-deployment and deployment-related variables.
When including only variables recorded pre-deployment (cognitive ability score and educational level) and gender (model 1), all variables predicted post-deployment PTSD. When deployment-related variables were added (model 2), this was no longer the case for cognitive ability score. However, when educational level was removed from the model adjusted for deployment-related variables, the association between cognitive ability and post-deployment PTSD became significant.
Pre-deployment lower cognitive ability did not predict post-deployment PTSD independently of educational level after adjustment for deployment-related variables.
Nissen, L.R., Karstoft, K.I., Vedtofte, M.S., Nielsen, A.B.S., Osler, M., Mortensen, E.L., Christensen, G.T. & Andersen, S.B. (2017) Cognitive ability and risk of post-traumatic stress disorder after military deployment: an observational cohort study. BJPsych Open. 3(6):274-280. doi: 10.1192/bjpo.bp.117.005736. eCollection 2017 Nov.