Richard P. Marshall

Combat, dissociation, and posttraumatic stress disorder in Australian Vietnam veterans.

The specificity of various wartime stressors for different posttraumatic stress disorder (PTSD) symptoms is inconsistently reported in the literature. Combat, wounding, and peritraumatic dissociation have not been assessed together in their effects on each of the various PTSD symptom clusters. This cohort study of a random sample of male Australian Army Vietnam veterans yielded psychiatric assessments of 641 subjects. PTSD measures comprised symptom criteria for reexperiencing, numbing and avoidance, hyperarousal, and PTSD diagnosis both lifetime and current within the past month. Logistic regression is used to examine the effects of combat, wounding, and peritraumatic dissociation together on PTSD. Combat experiences comprised four components derived from a principal components analysis of combat experiences: direct combat exposure, exposure to death and injury, exposure to civilian death and injury, and exposure to mutilation. Each was differentially related to reexperiencing, avoidance, hyperarousal, and PTSD diagnosis. Being wounded was not related to lifetime or current PTSD and peritraumatic dissociation was related to all diagnostic components of PTSD in the presence of other variables.

Posttraumatic stress disorder and comorbidity in Australian Vietnam veterans: risk factors, chronicity and combat

Objective: The objective of this study was to examine the relationship between combat-related posttraumatic stress disorder (PTSD) and comorbid DSM-III-R psychiatric diagnoses to determine commonalities in risk factors, relative onsets and the role of combat exposure. Method: An epidemiological cohort study using standardised psychiatric, social and health interviews was undertaken with a national random sample of male Australian Army Vietnam veterans. Interviews and searches of military records yielded risk factors for PTSD, which were examined for association with each psychiatric diagnosis. Relative onsets of PTSD and each Diagnostic Interview Schedule diagnosis were compared. Comorbidity odds ratios were adjusted for combat exposure effects using logistic regression, and the relation between each diagnosis and combat was assessed after controlling for PTSD. Results: Commonality of risk factor profile was evident for several diagnoses, and for many their onset preceded PTSD onset. Combat was independently related to only a few diagnoses after controlling for PTSD, and PTSD remained strongly associated with several conditions after controlling for combat exposure. Conclusions: The analysis suggests that the disorders that may constitute risk factors or vulnerabilities for PTSD comprise depression and dysthymia, antisocial personality disorder, agoraphobia and simple phobia, while those that may be consequent on PTSD are panic and generalised anxiety disorder, drug use disorders and somatoform pain disorder. Alcohol and drug use disorders and social phobia may have a mixed aetiology, while obsessive-compulsive disorder may be serendip-itously related to PTSD through an association with risk of combat. Gambling disorder is unrelated.

Risk Factors for Posttraumatic Stress Disorder in Australian Vietnam Veterans

Objective: The aims of this paper are to determine the risk factors for combat-related posttraumatic stress disorder (PTSD) and to examine the relative contribution of pre-military factors, pre-trauma psychiatric diagnoses, military factors such as combat posting, and combat and casualty stress exposure. Method: An epidemiological cohort study using standardised psychiatric, social and health interviews was undertaken with a national random sample of male Australian Army Vietnam veterans. Multivariate logistic regression was used to examine the relative contribution of factors derived from interview and from military records in four categories: pre-enlistment circumstances including home life, education, major life stress; pre-Vietnam psychiatric diagnoses; military experiences before and during Vietnam; and combat and stress experiences. Results: Of the 128 data items examined, significant associations were found for 39, in addition to combat stress. Pre-enlistment items accounted for about 3% of the deviance towards PTSD diagnosis, pre-enlistment psychiatric diagnosis about 13%, military variables about 7% and combat stress about 18%; all factors together accounted for 42%. Conclusions: The results confirm that pre-military and military variables make only a small but significant contribution to PTSD either alone or after controlling for combat stress; that psychiatric diagnoses of depression, dysthymia and agoraphobia make strong contributions to PTSD; but that combat stress makes the largest contribution even after controlling for the effects of other variables. Psychiatric diagnoses and combat stress appear to be independent in their effects on PTSD.

The Stressor Criterion and Diagnosing Posttraumatic Stress Disorder in a Legal Context

Bryant (1996) outlined a recent Federal Court case where an applicant claimed to be suffering from posttraumatic stress disorder (PTSD) following exposure to atomic testing in Maralinga. In his paper, Bryant (1996) discusses the legal definition of a stressor, highlighting the ambiguity which remains in the DSM-IV definition of the stressor criterion (American Psychiatric Association, 1994). In this comment, our aim is not to question Bryants argument concerning the ambiguity of the stressor criterion, but to question the view that there might be some way of objectifying the definition of a stressor in the diagnosis of PTSD, thereby standardising the diagnosis. Our perspective on the PTSD diagnosis is necessarily biased by our experience as clinicians and researchers in the field of war-related trauma. Although PTSD has been conceptualised as an anxiety reaction that follows in the wake of exposure to an extreme event, there may not be a discrete class of stressors that cause PTSD. In supporting this view, we argue that the etiology of PTSD is multidimensional. It follows that PTSD cannot be understood in terms of a cause-effect type relationship between the stressor and symptoms, as is required for the assessment of compensation/litigation claims in the courtroom setting.

Postwar experiences and treatment-seeking behavior in a community counselling setting

Previous research investigating the impact of postwar experiences on Vietnam veterans has focused on veteran morbidity. This emphasis has meant that the impact of these factors on treatment-seeking behavior has received little empirical attention. This study examined the association between postwar factors and treatment-seeking behavior in a sample of 692 Australian Vietnam veterans. Logistic regression analyses were used to compute the odds ratios associated with postwar experiences and self-referral to a community-based counselling service. Results suggest that veterans who reported experiencing negative feelings toward others when they first arrived home were more likely to seek treatment. Other factors, such as a veterans perception of societal attitudes and the reception they received, were not associated with treatment-seeking behavior.