Predicting mental illness in soldiers

We read with interest the article by Rona et al on mental health screening in the armed forces before the Iraq war and prevention of subsequent psychological morbidity.¹ We disagree with the conclusion that pre-deployment screening would not have reduced morbidity from common mental illnesses. This is too broad a conclusion. All that may be concluded is that the screening tools employed by the researchers did not predict morbidity.

When looking at the three main scores used (GHQ-12, SF-36, and PCL-C), it is clear that these tools were designed for a “snapshot screen” in time. None was designed as a predictor of future mental illness.^{2 3 4} Military deployment occupies a unique position in that it will almost invariably expose individuals to significant psychological insult. The concept of pre-deployment screening therefore poses the unique question: what predisposes an individual to mental illness given an imminent, predictable insult? To our knowledge, there is no assessment tool that is designed to answer this question.

We share the authors' disappointment that the commonly used mental health screening tools have not proved useful in predicting illness. However, we advise caution against a broad statement that screening for common mental disorders before deployment does not reduce morbidity. We must not discourage future researchers from devising more appropriate predictive tests for these debilitating diseases in this unique group of individuals.