Risk factors for posttraumatic stress disorder in Australian Vietnam veterans

Effect of Predeployment Psychiatric Diagnoses on Postdeployment Long-Term Sickness Absence and Mental Health Problems Among Danish Military Personnel

Military personnel may withhold information on mental health problems (MHPs) for fear of not being permitted to deploy. Past or current MHPs may, however, increase the risk of postdeployment MHPs. Using psychiatric diagnoses rather than self-report assessments in predeployment screening may be a more effective screening strategy for determining deployment fitness. This retrospective follow-up study investigated (a) the extent to which predeployment childhood and adult psychiatric diagnoses predicted postdeployment MHPs, measured as psychiatric diagnosis and the purchase of psychiatric drugs, and long-term sickness absence among formerly deployed Danish military personnel and (b) whether perceived combat exposure moderated or mediated the effect of predeployment psychiatric diagnoses. Complete data were available for 7,514 Danish military personnel who answered questions on perceived combat exposure between 6-8 months after returning from their first deployment to the Balkans, Iraq, or Afghanistan. Data on all psychiatric diagnoses given at Danish hospitals, all medicine purchases, and all sickness absences were retrieved from nationwide research registers. Personnel with predeployment psychiatric diagnoses had a statistically significant higher risk for both postdeployment long-term sickness absence, hazard ratio (HR) = 2.06, 95% CI [1.52, 2.80]; and postdeployment MHPs, HR = 2.38, 95% CI [1.73, 3.27], than personnel without a predeployment psychiatric diagnosis. Personnel with a predeployment psychiatric diagnosis demonstrated a higher risk of reporting high levels of perceived combat exposure. Perceived combat exposure was not found to moderate or mediate the effect of a predeployment psychiatric diagnosis on the two outcomes. Additional findings, limitations, and implications are discussed.

Combat, Posttraumatic Stress Disorder, and Smoking Trajectory in a Cohort of Male Australian Army Vietnam Veterans

Background

Whether trauma exposure itself or consequent posttraumatic stress disorder (PTSD) is primarily responsible for smoking and failure to quit remains unclear.

Methods

A cohort of male Australian Vietnam veterans (N = 388) was interviewed twice, 22 and 36 years after their return to Australia using standardized psychiatric diagnostic and health interviews and assessment of combat exposure. The smoking trajectory over time revealed a spectrum of outcomes (never smoked, early quitters, late quitters, and continuing smokers). Analysis used multivariate statistics to assess the relative contributions of combat trauma exposure and PTSD while controlling for potential confounders.

Results

The trajectory of smoking over time revealed that 21.9% of veterans had never smoked, 45.1% had quit smoking by the time of wave 1, 16.2% were current smokers at wave 1 who had quit by the time of wave 2, 2.8% were late adopters who were current smokers, and 13.9% were continuing smokers. Smoking was associated in single-predictor models with demographics, intelligence, combat exposure, PTSD symptom clusters and diagnosis, and alcohol disorders. Multivariate analysis revealed that PTSD, combat, and intelligence were related to the smoking spectrum but, after adding demographics and other Axis I psychiatric diagnoses, only combat remained significant. No PTSD symptom cluster uniquely predicted smoking status.

Conclusions

The results suggest that trauma exposure in the form of military combat may be a more robust predictor of smoking status over time than PTSD. It may be stress itself, rather than poststress disorder, that is more germane to smoking and failure to quit.

Implications

Exposure to traumatic stress and development of PTSD have been implicated separately in the maintenance of smoking. This longitudinal cohort study of smoking in war veterans up to three decades postwar enabled evaluation of traumatic stress exposure in combat and the course of PTSD in smoking and quitting while controlling for intelligence, background disadvantage, and other psychiatric conditions. Combat rather than PTSD emerged as more significant to smoking status, suggesting that it may be the traumatic stress itself rather than the development of a poststress disorder that is more germane to smoking in war veterans.

A cluster-analytic approach to determining drinking motives and personality typologies: Trauma group differences and respective relations to PTSD and problematic alcohol use

Veterans with posttraumatic stress disorder (PTSD) are at elevated risk for alcohol use problems, a relationship commonly explained by using alcohol to cope with unpleasant symptoms of PTSD. However, patterns of alcohol use motives, more broadly, have not been well characterized in veteran samples, nor have they been evaluated in the context of other relevant factors, such as normative personality traits. The aims of the present study were to identify empirically derived drinking motive and personality typologies to determine whether these typologies differ as a function of PTSD status (i.e., nontrauma control, trauma exposed-no PTSD, and PTSD) and to evaluate associations between typology and PTSD symptom severity and alcohol consumption, respectively. Cluster analyses identified a 4-cluster solution. Results indicated that these typologies differed significantly according to trauma group as well as across levels of PTSD symptom severity and alcohol use. Specifically, Cluster 4 represented individuals at highest risk for both PTSD symptom severity and alcohol use compared to all the other typologies; Cluster 1 demonstrated lowest risk for PTSD symptom severity and alcohol use compared to all other typologies; and although Clusters 2 and 3 did not differ according to PTSD symptom severity, individuals in Cluster 2 had significantly higher alcohol use. These results represent certain "at risk" versus "protective" typologies that may facilitate the identification of individuals at risk for comorbid PTSD and problematic alcohol use. (PsycINFO Database Record

Factors associated with posttraumatic stress disorder symptoms among community volunteers during the Sewol ferry disaster in Korea

BACKGROUND

The aim of this study was to investigate the characteristics associated with volunteerism and identify the factors that contributed to posttraumatic stress disorder symptoms among community volunteers following the Sewol ferry disaster in Korea.

METHODS

In total, 2,298 adults (aged 30-70 years) from the Jin-do area, where the Sewol ferry disaster occurred, participated in this study. A cross-sectional survey was conducted 1 month after the disaster. Posttraumatic stress disorder (PTSD), depression, and anxiety symptoms were assessed using the Impact of Events Scale Revised (IES-R), Center for Epidemiologic Studies Depression Scale (CES-D), and Beck Anxiety Inventory (BAI).

RESULTS

Clinically relevant PTSD symptoms were observed in 151 (19.7%) community volunteers. Age, education, socioeconomic status, religion, and lifetime experiences of natural disasters were associated with volunteering following the disaster. Logistic regression analysis revealed that volunteering was a significant risk factor for the development of PTSD symptoms in this sample. Personal experience with property damage associated with a traumatic event, depression, and anxiety were also significantly associated with the PTSD symptoms of community volunteers.

CONCLUSIONS

Our results suggest the need for assessment and mental health programs for community volunteers performing rescue work to prevent posttraumatic stress symptoms following a community disaster.

Intergenerational transmission of post-traumatic stress disorder in Australian Vietnam veterans' families

OBJECTIVE

To assess the association between parental post-traumatic stress disorder (PTSD) and offspring PTSD and its specificity for other disorders in a non-clinical epidemiological cohort of Australian Vietnam veterans, their partners and their sons and daughters.

METHOD

Veterans were interviewed twice, in 1992-1994 and 2005-2006; partners were interviewed in 2006-2007, and their offspring in 2012-2014. A total of 125 sons and 168 daughters were interviewed from 197 families, 137 of which also included partners who were the mothers of the children. Statistical analysis used multi-level modelling to compute odds ratios and 95% confidence intervals while controlling for clustering effects within families. Parent PTSD diagnoses were examined for associations with offspring trauma exposure, PTSD and other psychiatric diagnoses.

RESULTS

Veteran PTSD increased the risk of PTSD and no other disorder in both sons and daughters; partner PTSD did not. Veteran depression was also a risk factor for sons' PTSD, and alcohol disorder was linked to alcohol dependence in sons and PTSD in daughters, but not when controlling for veteran PTSD.

CONCLUSION

We conclude that PTSD in a Vietnam veteran father increases the risk specifically for PTSD in his sons and daughters.

Psychosomatic Status, Personality Traits, and Coping Styles of Bereaved and Non-Bereaved Survivors of the 2008 Wenchuan Earthquake, China

OBJECTIVES

This study examined personality, coping styles, and psychosomatic characteristics and their relationships in bereaved and non-bereaved earthquake survivors.

STUDY DESIGN

Cross-sectional survey.

METHODS

A survey was conducted with a sample of 102 non-bereaved survivors and 79 bereaved survivors from Mianyang, Anyang, and similar districts 2 weeks after Wenchuan earthquake. Survivors completed questionnaires, including items about demographics, personality characteristics, coping styles, and psychosomatic status.

RESULTS

Bereaved survivors had lower scores for gregariousness, trust, and optimism, but higher scores for depressed mood, loneliness, becoming easily fearful, irritation, and anxiety than non-bereaved survivors. In addition, bereaved participants scored higher for avoiding problems, self-blame, and fantasy coping styles than non-bereaved ones. Personality and coping styles significantly correlated with psychosomatic status in bereaved and non-bereaved survivors. Optimism and openness to feelings personality characteristics, and self-blame, avoiding problems, and rationalization coping styles significantly predicted psychosomatic status of bereaved survivors, whereas openness to fantasy, optimism, order, and trust personality characteristics, and self-blame and avoiding problems coping styles significantly predicted psychosomatic status of non-bereaved survivors.

CONCLUSION

Earthquake survivors experienced post-traumatic stress disorder (PTSD) symptoms and negative emotions. Bereaved survivors experienced more serious PTSD symptoms and negative emotions relative to non-bereaved survivors. Appropriate psychological crisis interventions should be conducted for earthquake survivors, especially bereaved survivors.

A meta-analysis of risk factors for combat-related PTSD among military personnel and veterans

Post-traumatic stress disorder (PTSD), a complex and chronic disorder caused by exposure to a traumatic event, is a common psychological result of current military operations. It causes substantial distress and interferes with personal and social functioning. Consequently, identifying the risk factors that make military personnel and veterans more likely to experience PTSD is of academic, clinical, and social importance. Four electronic databases (PubMed, Embase, Web of Science, and PsycINFO) were used to search for observational studies (cross-sectional, retrospective, and cohort studies) about PTSD after deployment to combat areas. The literature search, study selection, and data extraction were conducted by two of the authors independently. Thirty-two articles were included in this study. Summary estimates were obtained using random-effects models. Subgroup analyses, sensitivity analyses, and publication bias tests were performed. The prevalence of combat-related PTSD ranged from 1.09% to 34.84%. A total of 18 significant predictors of PTSD among military personnel and veterans were found. Risk factors stemming from before the trauma include female gender, ethnic minority status, low education, non-officer ranks, army service, combat specialization, high numbers of deployments, longer cumulative length of deployments, more adverse life events, prior trauma exposure, and prior psychological problems. Various aspects of the trauma period also constituted risk factors. These include increased combat exposure, discharging a weapon, witnessing someone being wounded or killed, severe trauma, and deployment-related stressors. Lastly, lack of post-deployment support during the post-trauma period also increased the risk of PTSD. The current analysis provides evidence of risk factors for combat-related PTSD in military personnel and veterans. More research is needed to determine how these variables interact and how to best protect against susceptibility to PTSD.

Predicting post-trauma stress symptoms from pre-trauma psychophysiologic reactivity, personality traits and measures of psychopathology

Background

Most individuals exposed to a traumatic event do not develop post-traumatic stress disorder (PTSD), although many individuals may experience sub-clinical levels of post-traumatic stress symptoms (PTSS). There are notable individual differences in the presence and severity of PTSS among individuals who report seemingly comparable traumatic events. Individual differences in PTSS following exposure to traumatic events could be influenced by pre-trauma vulnerabilities for developing PTSS/PTSD.

Methods

Pre-trauma psychological, psychophysiological and personality variables were prospectively assessed for their predictive relationships with post-traumatic stress symptoms (PTSS). Police and firefighter trainees were tested at the start of their professional training (i.e., pre-trauma; n = 211) and again several months after exposure to a potentially traumatic event (i.e., post-trauma, n = 99). Pre-trauma assessments included diagnostic interviews, psychological and personality measures and two psychophysiological assessment procedures. The psychophysiological assessments measured psychophysiologic reactivity to loud tones and the acquisition and extinction of a conditioned fear response. Post-trauma assessment included a measure of psychophysiologic reactivity during recollection of the traumatic event using a script-driven imagery task.

Results

Logistic stepwise regression identified the combination of lower IQ, higher depression score and poorer extinction of forehead (corrugator) electromyogram responses as pre-trauma predictors of higher PTSS. The combination of lower IQ and increased skin conductance (SC) reactivity to loud tones were identified as pre-trauma predictors of higher post-trauma psychophysiologic reactivity during recollection of the traumatic event. A univariate relationship was also observed between pre-trauma heart rate (HR) reactivity to fear cues during conditioning and post-trauma psychophysiologic reactivity.

Conclusion

The current study contributes to a very limited literature reporting results from truly prospective examinations of pre-trauma physiologic, psychologic, and demographic predictors of PTSS. Findings that combinations of lower estimated IQ, greater depression symptoms, a larger differential corrugator EMG response during extinction and larger SC responses to loud tones significantly predicted higher PTSS suggests that the process(es) underlying these traits contribute to the pathogenesis of subjective and physiological PTSS. Due to the low levels of PTSS severity and relatively restricted ranges of outcome scores due to the healthy nature of the participants, results may underestimate actual predictive relationships.

Antisocial behavioral syndromes and additional psychiatric comorbidity in posttraumatic stress disorder among u.s. Adults: results from wave 2 of the national epidemiologic survey on alcohol and related conditions

BACKGROUND

Despite the relatively high prevalence of antisocial personality disorder (ASPD) in individuals with posttraumatic stress disorder (PTSD), associations of ASPD with clinical presentation of PTSD, including additional comorbidity, have not been investigated.

OBJECTIVE

To present nationally representative findings on associations of DSM-IV ASPD versus syndromal adult antisocial behavior without conduct disorder before age 15 with additional psychiatric disorders among U.S. adults with PTSD.

METHOD

Face-to-face interviews using the Alcohol Use Disorder and Associated Disabilities Interview Schedule-DSM-IV version in the Wave 2 National Epidemiologic Survey on Alcohol and Related Conditions (n=34,653).

RESULTS

After adjustment for sociodemographics and additional comorbidity, both antisocial syndromes were significantly associated with bipolar I, attention-deficit/hyperactivity, substance use, and paranoid, schizoid, histrionic, and obsessive-compulsive personality disorders among respondents with PTSD. Odds of major depressive and generalized anxiety disorders were significantly reduced among men with ASPD.

CONCLUSIONS

Interventions targeting PTSD may require attention to co-occurring antisociality and additional comorbidity.

An open-label study of mirtazapine as treatment for combat-related PTSD

BACKGROUND

Posttraumatic stress disorder (PTSD) is common among war veterans. Antidepressants are effective in reducing symptoms and associated disability for some patients.

OBJECTIVE

To assess the effectiveness of mirtazapine for combat-related PTSD among veterans treated in an Australian hospital.

METHODS

This open-label prospective study assessed the effectiveness of mirtazapine as empirical treatment for combat-related PTSD. The initial dose was 15 mg at night, titrated against response to 15-45 mg. PTSD symptoms were assessed using the Mississippi Scale for Combat-Related Posttraumatic Stress Disorder and the Clinician-Administered PTSD Scale (CAPS). Subjects also completed the Hospital Anxiety and Depression Scale (HADS). Body weight and biochemical assessments, including fasting blood glucose (FBG), total serum cholesterol, and serum triglycerides, were also measured. Baseline measurements were repeated after 12 weeks.

RESULTS

During the 18-month recruitment phase, 17 subjects were enrolled and 13 completed the protocol. The CAPS measurement decreased from a mean pretreatment score of 87.5 to 64.4 (p = 0.01). In 4 cases, the CAPS score decreased to below the diagnostic cut-point, consistent with a remission of PTSD. The Mississippi scale measurement decreased from a mean pretreatment score of 126.6 to 115.5 (p < 0.01). The mean HADS anxiety score decreased from 15.6 +/- 4.2 to 13.5 +/- 5.6 (p = 0.016), although the proportion of subjects with scores above the diagnostic cut-point remained high. The mean HADS depression score at baseline was not significantly different from the postintervention score. One subject had a postintervention FBG of 155 mg/dL (consistent with diabetes mellitus), which was increased from the baseline level of 83 mg/dL. All subjects experienced an increase in body weight. One subject had an increase in body weight of 8.75 kg (8.4%) from baseline.

CONCLUSIONS

Although small and with methodological limitations, this study suggests that mirtazapine is an effective treatment for combat-related PTSD. Additional research incorporating an appropriately powered, double-blind, placebo-controlled study design is required.

The contribution of prior psychological symptoms and combat exposure to post Iraq deployment mental health in the UK military

This study assessed the contribution of baseline psychological symptoms, combat exposure, and unit support in the etiology of posttraumatic stress disorder (PTSD), and psychological distress. From 2004-2006, 67% of a random sample of 2,820 participants who had been assessed for psychological symptoms in 2002 were reassessed. Baseline psychological symptoms, combat exposure, and unit support factors were associated with the outcomes and the effect sizes for combat exposure were marked for PTSD symptoms. Adjustment for baseline psychological symptoms did not modify the pattern of association of group cohesion and combat exposures. The authors concluded that combat exposure and group cohesion have an effect on mental health outcomes independent of previous mental health status, which explains why screening prior to deployment is ineffective.

Trauma history characteristics and subsequent PTSD symptoms in motor vehicle accident victims

The present study examined the relationship between trauma history characteristics (number and type of traumas, age at first trauma, and subjective responses to prior traumas) and the development of posttraumatic stress disorder (PTSD) symptoms following a motor vehicle accident (MVA). One hundred eighty-eight adult MVA victims provided information about prior traumatization and were evaluated for PTSD symptoms 6 weeks and one year following the MVA. Results indicated that after controlling for demographics and depression, prior trauma history characteristics accounted for a small, but significant amount of the variance in PTSD symptoms. Distress from prior trauma and number of types of prior traumas were the most meaningful trauma history predictors. Results encourage further evaluation of trauma history as a multifaceted construct.

Trauma, PTSD, and physical health: an epidemiological study of Australian Vietnam veterans

OBJECTIVE

This study aimed to examine the relative contributions to physical health of combat trauma exposure and posttraumatic stress disorder (PTSD), which have both been implicated separately in poorer physical health but whose unconfounded effects have not been teased out.

METHODS

Data from an epidemiological study of Australian Vietnam veterans, which used personal interviews and standardized physical and psychiatric health assessments, provided the means to assess the independent and joint effects of psychological trauma exposure and PTSD on a wide range of self-reported measures of physical health. Trauma exposure was measured by published scales of combat exposure and peritraumatic dissociation. Logistic regression modeling was used to assess the relative importance of trauma exposure and PTSD to health while controlling for a set of potential confounders including standardized psychiatric diagnoses.

RESULTS

Greater health service usage and more recent health actions were associated more strongly with PTSD, which was also associated with a range of illness conditions coded by the World Health Organization International Classification of Diseases, 9th Edition (asthma, eczema, arthritis, back and other musculoskeletal disorders, and hypertension) both before and after controlling for potential confounders. In contrast, combat exposure and peritraumatic dissociation were more weakly associated with a limited number of unconfounded physical health outcomes.

CONCLUSIONS

This study provided evidence that PTSD, rather than combat exposure and peritraumatic dissociation, is associated with a pattern of physical health outcomes that is consistent with altered inflammatory responsiveness.

Posttraumatic stress disorder symptoms following media exposure to tragic events: impact of 9/11 on children at risk for anxiety disorders

With the extensive media coverage on September 11, 2001, adults and children indirectly witnessed the terrorist attacks leading to the deaths of almost 3,000 people. An ongoing longitudinal study provided the opportunity to examine pre-event characteristics and the impact of this media exposure. We assessed symptoms of PTSD in 166 children and 84 mothers who had no direct exposure to the 9/11 attacks. The sample included children who had parents with or without anxiety and mood disorders, and who had been assessed for the presence or absence of temperamental behavioral inhibition (BI). We found a 5.4 percent rate of symptomatic PTSD in response to 9/11 in children and 1.2 percent in their mothers. Children's identification with victims of the attack, and for younger children, the amount of television viewing predicted increased risk of PTSD symptoms. Parental depression was associated with higher symptoms, and pre-event levels of family support was associated with a lower risk for PTSD symptoms. BI in children was also linked to lower rates of PTSD symptoms, suggesting that a cautious and fearful approach to novelty may offer protection against exposure to media-based traumatic images. Media viewing of tragic events is sufficient to produce PTSD symptoms in vulnerable populations such as children. Given the links between PTSD symptoms and viewing habits, parental monitoring of media exposure may be important for younger children.

Are male disaster workers with Vietnam military service at greater risk for ptsd than peers without combat history?

This study examined whether male disaster workers with Vietnam service histories were at risk for posttraumatic stress disorder when compared with colleagues following duties at Ground Zero. The study compared participants from ongoing psychiatric screening of disaster workers: those with Vietnam service (Vietnam veteran; N = 125), those without trauma history (no trauma; N = 116); and those with childhood physical abuse but no combat history (physical abuse; N = 57). ANOVA indicated the trauma groups differed significantly in clinician-rated posttraumatic stress disorder severity (p < 0.005). However, post hoc analyses revealed the Vietnam veteran group did not differ significantly from the no trauma group; both had significantly lower severity compared with the physical abuse group. It should be noted that veterans in this sample, unlike in many studies, were in the workforce. Research with different veteran groups is warranted to clarify further the relation of combat experience and symptoms in disaster workers.

A multiple-indicator multiple-cause model for posttraumatic stress reactions: personality, coping, and maladjustment

OBJECTIVE

This study aimed to develop a multiple-indicator multiple-cause model (MIMIC) to describe the relationship among posttraumatic stress (PTSD) responses, general health problems, death anxiety, personality factors, and coping strategies among community residents exposed to the technological disasters of aircraft and train crashes.

MATERIALS AND METHODS

One hundred forty-eight community residents, after exposure to the aircraft or train crash, were assessed using the Impact of Event Scale, the General Health Questionnaire-28, the Death Anxiety Scale, the Eysenck Personality Questionnaire, and the Ways of Coping Checklist. The control group (n = 90) comprised members of the general public, who had not been exposed to the disasters, from another city.

RESULTS

The model showed significant associations between the impact of the disaster and general health problems, which varied depending on where community residents lived in relation to the disaster site, whether they were present when the disaster occurred, and the type of disaster. The model also suggested that death anxiety was associated with type of disaster and neuroticism. The model supported the interactive model in that personality factors interacted with coping strategies in maintaining or generating PTSD and general health problems.

CONCLUSIONS

After exposure to technological disasters, community residents could develop PTSD and general health problems; however, increased death anxiety was a separate psychological reaction. The interaction between certain personality traits and coping strategies was one reason for PTSD and general health problems.

Occupational risk factors for ill health in Gulf veterans of the United Kingdom

OBJECTIVES

To study the association between occupational factors specific to the Armed Forces (rank, functional roles, Service, regular or reservist status and deployment factors) and symptomatic health problems in Gulf veterans, after sociodemographic and lifestyle factors have been accounted for.

DESIGN

A postal cross sectional survey of randomly selected UK Gulf veterans was conducted six to seven years after the Gulf conflict. Physical ill health was measured using the Fatigue Questionnaire and a measure of the Centers for Disease Control and Prevention (CDC) multi-symptom syndrome. Psychological ill health was measured using the General Health Questionnaire and a post-traumatic stress measure.

SETTING

Population of servicemen who were serving in the UK Armed Forces during the Gulf conflict between 1 September 1990 and 30 June 1991.

PARTICIPANTS

3297 Gulf veterans.

MAIN RESULTS

In multivariate logistic regression, there was an inverse relation between higher rank and psychological and physical ill health (test of trend: General Health Questionnaire, p=0.004; post-traumatic stress, p=0.002; fatigue, p=0.015; CDC case, p=0.002). Having left the Armed Forces was associated with a two to three times increase in reporting ill health. Of the deployment factors, there was a weak association between being deployed as an individual reinforcement in a combat role and post-traumatic stress but there was no association between receiving pre-deployment training or post-deployment leave and ill health. Marital status and smoking were associated with psychological and physical ill health.

CONCLUSIONS

Rank was the main occupational factor associated with both psychological and physical ill health in Gulf veterans. This may parallel the associations between socioeconomic status and morbidity in civilian populations. Ill health seems to be greater in those who return to civilian life. Sociodemographic factors also seem to be important in ill health in Gulf veterans.

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 serendipitously related to PTSD through an association with risk of combat. Gambling disorder is unrelated.