The Associations Between Physical and Psychological Symptoms and Traumatic Military Deployment Exposures

Current paradigms regarding the effects of traumatic exposures on military personnel do not consider physical symptoms unrelated to injury or illness as independent outcomes of trauma exposure, characteristically dealing with these symptoms as comorbidities of psychological disorders. Our objective was to ascertain the proportions of deployed military personnel who experienced predominantly physical symptoms, predominantly psychological symptoms, and comorbidity of the two and to examine the association between traumatic deployment exposures (TDEs) and these symptomatic profiles. Data were taken from a cross-sectional study of Australian Defence Force personnel who were deployed to the Middle East during 2001-2009 (N = 14,032). Four groups were created based on distributional splits of physical and psychological symptom scales: low-symptom, psychological, physical, and comorbid. Multinomial logistic regression models assessed the probability of symptom group membership, compared with low-symptom, as predicted by self-reported TDEs. Group proportions were: low-symptom, 78.3%; physical, 5.0%; psychological, 9.3%; and comorbid, 7.5%. TDEs were significant predictors of all symptom profiles. For subjective, objective, and human death and degradation exposures, respectively, the largest relative risk ratios (RRRs) were for the comorbid profile, RRRs = 1.47, 1.19, 1.48; followed by the physical profile, RRRs = 1.27, 1.15, 1.40; and the psychological profile, RRRs = 1.22, 1.07, 1.22. Almost half of participants with physical symptoms did not have comorbid psychological symptoms, suggesting that physical symptoms can occur as a discrete outcome trauma exposure. The similar dose-response association between TDEs and the physical and psychological profiles suggests trauma is similarly associated with both outcomes.