Childhood determinants of mental health and related outcomes in the Australian Defence Force

Abstract

Background: The impact of military service on mental health has long been a focus of scientific and political debate. Historically, underlying vulnerability (moral weakness) was blamed for the psychological effects of war. Pressure from veteran communities in the aftermath of the Vietnam war saw the advent of a diagnosis to encapsulate the pathological psychological effects of trauma, namely PTSD. This dramatically shifted the focus from underlying vulnerability to a single recent traumatic event, upon which the diagnostic criterion of PTSD depends. Meanwhile, research in civilians demonstrated that childhood adversity is a major determinant of disorder through the lifespan. In addition, childhood adversity was found to be more prevalent in serving and ex-serving military personnel than in civilians. I aimed to conduct a detailed and nuanced analysis of specific childhood factors (trauma and mental disorder) alongside adult factors in determining a broad spectrum of mental disorders (including PTSD, depression and anxiety) and related outcomes (suicidality, somatic symptoms, distress and functioning) in current and ex-serving military populations, and where possible, to compare with other populations. Methods: I have taken advantage of the unique opportunity to examine data from the extensive health surveillance program in the ADF, specifically the 2010 ADF MHPWS, the ADF MEAO Prospective Study, and the ADF Transition and Wellbeing Research Programme. Where possible, I also compared with populations matched on sociodemographic variables, such as the 2007 ABS NSMHWS. Much of the data were detailed interview data. This allowed for the interrogation of childhood factors. Results: There was a higher prevalence of childhood trauma in ADF than civilian employed men, particularly non-interpersonal childhood trauma in the oldest age groups. In ADF and civilian employed men, childhood interpersonal trauma (which was more prevalent in ADF than civilian employed men), was not just associated with PTSD, but also the whole spectrum of past-year mental disorders. However, all of these associations were mediated by the spectrum of childhood mental disorders, with the exception of suicidality which was fully mediated by childhood anxiety alone. In the Transition population, childhood anxiety was not only an important determinant of adult outcomes (PTSD, anxiety, suicidality and multiple symptoms) it also appeared to fully mediate the relationship between childhood trauma and these outcomes (with the exception of suicidality). Conclusion These analyses have enabled us to develop a rich and nuanced understanding of the childhood determinants of adult health and associated outcomes along with mediator pathways in different populations. A lifetime perspective has shed light on the relationships between childhood factors and more proximal adult factors in determining poor outcomes. It has highlighted the importance of evaluating childhood trauma profile in determining adult vulnerabilities and of the impact of trauma across the spectrum of mental disorders (not solely PTSD), allowing a rare glimpse, albeit retrospective, of reactivity to previous traumatic events. This has proved exceedingly fruitful and lays the groundwork for further prospective research to better inform early prevention and intervention strategies. These studies highlight both the utility and necessity for continued consistent epidemiological surveillance of these populations.