The psychiatric consequences of physical injury in military personnel: predicting and managing the risk Alexander C McFarlane Stevelink et al’s 1 review of the comorbid- ity between physical injury and mental disorders is a timely reminder of the chal- lenges involved in rehabilitating injured military personnel. It is critical that there is ongoing systematic screening for psychi- atric disorders in combat injured service personal because of the role that depres- sion, post-traumatic stress disorder (PTSD) and anxiety have in further increasing the disability in individuals who are already facing significant chal- lenges in their rehabilitation. The high rates of psychiatric disorder reported by Stevelink et al 1 are not sur- prising, given the proximity and risk of death that must accompany many of the injuries described, particularly traumatic amputations. The physical injury further adds a reality to the confrontation with death that has become imprinted on the individual’s mind and then is replayed in the traumatic memories that represent a major driver to psychopathology. As the authors highlighted, the timing of the assessment is an important issue to consider in studies of comorbid physical and psychiatric injury. Psychological mor- bidity can have a delayed onset 2 and as such the assessment time frame might account for the variable prevalence of dis- order in the studies of this review. For example, Grieger et al 3 found that, at 7 months post serious battlefield injury, 78% of those who had either depression or PTSD did not have a mental disorder when initially assessed 1-month postinjury. Hence, time is a critical variable to con- sider when discussing the associated rates. Another factor that can make it difficult to compare across studies and may account for differing rates described in the review is the variability of the sam- pling procedures, such as convenience sampling and the absence of reported response rates. These problems highlight the importance of prospective longitu- dinal studies, as Stevelink et al 1 men- tioned. It is important to carefully document injured service personnel’s rehabilitation and negotiation of health- care systems over time, including long- term follow-up periods, as rates of psychi- atric disorder cannot be assumed to diminish with the course of time. The accuracy of case detection of psychiatric disorder, the barriers to care and the quality of the care provided also require careful measurement. Against this back- ground, perhaps the substantial prevalence of concurrent psychiatric injuries reported in the review, rather than any exact rates, should be emphasised. Varying rates of disorder among similarly injured personnel of different nationalities could relate to the striking differences in veterans’ healthcare between nations. This potential confound was not addressed in this review. Different international compen- sation systems could also impact disorder rates. A recent longitudinal study high- lighted that the stress created by the claims process, rather than the seeking of compen- sation per se, can have a major negative impact on psychological morbidity. 4 This variable is also important to document in studies of veterans needing pension entitle- ments for access to care. The review drew important conclusions about the range of psychopathology in these populations and the need to expand the focus beyond PTSD. Large longitu- dinal studies of consecutive cohorts of injured civilians admitted for hospital treatment have also highlighted the sub- stantial rates of concurrent psychiatric dis- order, the range of disorders diagnosed and their impact on functional outcomes. 5 In fact this study found that generalised anxiety disorder (9%) and major depres- sive disorder (9%) were more common than PTSD (6%). Twelve months postin- jury 31% of patients had a psychiatric dis- order, this disorder being a first life-time episode experienced in 22%. These find- ings further highlight the review’s conclu- sions about the range of psychopathology, including that beyond PTSD. Despite the ongoing clinical contact in the rehabilita- tion setting, it is often the case that a sig- nificant number of individuals have disorders that go unidentified and there- fore untreated. 6 Beyond the obvious psychological explanations for the associations described in the review, biological substrates of injury may play an important role in the onset of psychiatric disorders. For example, patients with traumatic amputa- tions can experience phantom limb phe- nomena and these may be enduring triggers to the memory of the traumatic event. However, there has been little exploration as to the extent to which the underlying denervation and cortical reorganisation that occur in phantom limb patients 7 might be contributing to the disrupted neural connectivity in PTSD or depression. Similarly, in spinal injuries, high level of cord transection has been hypothesised to impact on the risk of PTSD where denervation of the sympa- thetic system may be protective. 8 The lower rates of PTSD in those with quadri- plegia compared with lower level cord transections in Stevelink et al’s 1 review are consistent with this idea. The role of cytokines as an aetiological factor in psychiatric disorders has been the focus of recent interest and has been tar- geted in treatment studies. 9 10 The systemic inflammation that accompanies severe injur- ies may increase risk of psychological dis- order. Additionally, the treatment of the acute inflammation may impact subsequent rates of psychiatric illness. This possibility is supported by the replicated finding that larger doses of narcotic analgesia used during hospitalisation, independent of the severity of injury, are associated with lower probability of psychiatric morbidity. 11 Similarly, studies that have documented cor- tisone use in intensive care have found that it may have a protective effect against the development of PTSD. 12 Hence, there may be both beneficial and counter-therapeutic consequences of the acute biological treat- ments of physical injuries that impact on psychiatric complications. Finally, an issue not addressed in the review is the effect of concurrent head injury on the long-term rehabilitation of the physically injured. Increasingly, the psychiatric literature documents that the rates of psychiatric disorder are higher in those with mild traumatic brain injury. 5 Veterans with even more severe head injuries pose an even greater challenge in rehabilitation. This is a factor that requires documentation in all studies examining the interaction between the physical and psychological injuries of war. This high- lights the importance of ongoing auditing of the substantial numbers of disabled vet- erans from recent conflicts. Competing interests None. Correspondence to Professor Alexander C McFarlane, Centre for Traumatic Stress Studies, University of Adelaide, Level 2/122 Frome Street, Adelaide, SA 5000, Australia; alexander.mcfarlane@adelaide.edu.au McFarlane AC. Occup Environ Med Month 2015 Vol 0 No 0 1 Commentary OEM Online First, published on January 9, 2015 as 10.1136/oemed-2014-102684 Copyright Article author (or their employer) 2015. Produced by BMJ Publishing Group Ltd under licence. group.bmj.com on January 21, 2015 - Published by http://oem.bmj.com/ Downloaded from