Trauma, dissociation, and antiretroviral adherence among persons living with HIV/AIDS

Background

There are approximately 1,000,000 persons living with HIV/AIDS (PLH) in the United States; to reduce rates of new infection and curb disease progression, adherence to HIV medication among PLH is critical. Despite elevated trauma rates in PLH, no studies to date have investigated the relationship between dissociation, a specific symptom of trauma, and HIV medication adherence. We hypothesized that Post-Traumatic Stress Disorder (PTSD) symptoms would be associated with lower adherence, and that dissociation would moderate this relationship.

Methods

Forty-three individuals with HIV were recruited from community-based clinics to participate in a cross-sectional study. The relationship of trauma, dissociation, and their interaction to the probability of antiretroviral adherence was assessed using a hierarchical binary logistic regression analysis.

Results

Among 38 eligible participants, greater PTSD was associated with lower odds of adherence (OR = .92, p < .05). Dissociation moderated the effect of PTSD on adherence, resulting in lower odds of adherence (OR = .95, p < .05). PTSD symptoms were significantly associated with lower odds of adherence in individuals reporting high levels of dissociation (OR = .86, p < .05) but not in those reporting low levels of dissociation (OR = 1.02, p > .05).

Conclusions

This is the first study to demonstrate a relationship between dissociation and medication adherence. Findings are discussed in the context of clinical management of PLH with trauma histories and the need for interventions targeting dissociative symptomatology to optimize adherence.     

Acute panicogenic, anxiogenic and dissociative effects of carbon dioxide inhalation in patients with post-traumatic stress disorder (PTSD)

Background

Increased anxiety and panic to inhalation of carbon dioxide (CO₂) has been described in patients with anxiety disorders, especially panic disorder, compared to healthy subjects. Post-traumatic stress disorder (PTSD) has been hypothesised to resemble panic disorder and is currently classified as an anxiety disorder in DSM-IV. However, there are only very few data available about the sensitivity of patients with PTSD to CO₂.

Methods

In 10 patients with PTSD, 10 sex- and age-matched healthy subjects and 8 patients with panic disorder we assessed anxiety, panic, dissociative and PTSD symptoms before and after a single vital capacity inhalation of 35% CO₂.

Results

Patients with PTSD showed an increased anxiety, panic and dissociative reaction to the inhalation of 35% CO₂ compared to healthy participants. PTSD subjects’ responses were indistinguishable from those of panic patients. Additionally, PTSD-typical symptoms like post-traumatic flashbacks were provoked in patients with PTSD after the inhalation of CO₂.

Conclusions

In our sample, PTSD was associated with an increased CO₂ reactivity, pointing to an increased susceptibility of PTSD patients to CO₂ challenge.     

A brief screening tool for assessing psychological trauma in clinical practice: development and validation of the New York PTSD Risk Score

Objective

The objective was to develop a brief posttraumatic stress disorder (PTSD) screening instrument that is useful in clinical practice, similar to the Framingham Risk Score used in cardiovascular medicine.

Methods

We used data collected in New York City after the World Trade Center disaster (WTCD) and other trauma data to develop a new PTSD prediction tool — the New York PTSD Risk Score. We used diagnostic test methods to examine different clinical domains, including PTSD symptoms, trauma exposures, sleep disturbances, suicidal thoughts, depression symptoms, demographic factors and other measures to assess different PTSD prediction models.

Results

Using receiver operating curve (ROC) and bootstrap methods, five prediction domains, including core PTSD symptoms, sleep disturbance, access to care status, depression symptoms and trauma history, and five demographic variables, including gender, age, education, race and ethnicity, were identified. For the best prediction model, the area under the ROC curve (AUC) was 0.880 for the Primary Care PTSD Screen alone (specificity=82.2%, sensitivity=93.7%). Adding care status, sleep disturbance, depression and trauma exposure increased the AUC to 0.943 (specificity=85.7%, sensitivity=93.1%), a significant ROC improvement (P<.0001). Adding demographic variables increased the AUC to 0.945, which was not significant (P=.250). To externally validate these models, we applied the WTCD results to 705 pain patients treated at a multispecialty group practice and to 225 trauma patients treated at a Level I Trauma Center. These results validated those from the original WTCD development and validation samples.

Conclusion

The New York PTSD Risk Score is a multifactor prediction tool that includes the Primary Care PTSD Screen, depression symptoms, access to care, sleep disturbance, trauma history and demographic variables and appears to be effective in predicting PTSD among patients seen in healthcare settings. This prediction tool is simple to administer and appears to outperform other screening measures.     

Dissociative psychopathology among opioid use disorder patients: exploring the “chemical dissociation” hypothesis

Background

Although early trauma is a well-recognized risk factor for both dissociation and substance abuse, there are inconsistent reports on the association between substance abuse and dissociation. This inconsistency may be resolved by the “chemical dissociation” hypothesis that suggests that some substance abuse patients may not exhibit high levels of dissociation, despite their trauma history, because they may achieve dissociative-like states through chemicals consumption. This article describes 2 studies aimed to (a) assess the incidence of dissociative psychopathology among recovering opioid use disorder (OUD) patients and (b) examine the chemical dissociation hypothesis.

Methods

One hundred forty-nine patients receiving treatment in a heroin recovery program and 46 controls were administered self-report measures of dissociation and childhood maltreatment in study 1. A similar battery and an assessment of addiction severity were completed by 50 methadone maintenance treatment (MMT) patients and 30 detoxified OUD patients in study 2. In addition, Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Dissociative Disorders-Revised was administered to a subsample of MMT and detoxified OUD patients.

Results

Patients with OUD reported higher levels of child maltreatment and dissociation than controls. Although MMT and detoxified patients did not differ in severity of addiction and child maltreatment, detoxified outpatients had higher levels of dissociation than MMT outpatients: 23% of the detoxified patients and 12% of the MMT patients were diagnosed with a dissociative disorder.

Conclusions

These findings support the chemical dissociation hypothesis of OUD and suggest that detoxification programs should take into consideration the high incidence of comorbid dissociative disorders among their recovering OUD patients.     

Dysfunctional schema modes, childhood trauma and dissociation in borderline personality disorder

Objective

To examine the relationship between dysfunctional schema modes, childhood trauma and dissociation in borderline personality disorder (BPD).

Method

30 BPD patients completed the Wessex Dissociation Scale (WDS), Childhood Trauma Questionnaire (CTQ), General Health Questionnaire (GHQ), and Schema Mode Questionnaire (SMQ).

Results

The ‘Angry and Impulsive Child’ and ‘Abandoned and Abused Child’ modes uniquely predicted dissociation scores. Childhood trauma did not predict dissociation scores.

Conclusions

Findings support the schema mode model of BPD [Young, J. E., Klosko, J. S., & Weishaar, M. E. (2003). Schema therapy: A practitioners guide. London: Guilford Press] and its emphasis on the role of dissociation. Clinically they support the emphasis on the identification and integration of dysfunctional parts of the personality in working with individuals diagnosed with BPD.     

Dissociation in eating disorders: relationship between dissociative experiences and binge-eating episodes

Objective

Several findings support the hypothesis that there is a relationship between dissociation and eating disorders (EDs). The aims of this study were as follows: (1) to assess whether ED patients show a higher level of dissociation than healthy control (HC) individuals or psychiatric control patients with anxiety and mood disorders and (2) to investigate the effects of dissociation on ED symptoms, specifically binge eating behavior.

Method

Fifty-four ED patients, 56 anxiety and mood disorders control patients, and 39 HC individuals completed the Eating Disorder Examination Questionnaire and the Dissociation Questionnaire. Each participant was asked about the number of binge eating episodes he or she had experienced in the past 4 weeks.

Results

The ED patients had higher levels of dissociation than both the psychiatric control group and the HC group. In the ED group, the number of binge episodes was related to the level of dissociation.

Discussion

Dissociative experiences are relevant in EDs, and binge eating is related to dissociation. In patients affected by the core psychopathologic beliefs of EDs (overevaluation of shape and weight), dissociation may allow an individual to initiate binging behavior, thus decreasing self-awareness and negative emotional states, without having to deal with the long-term consequences of their actions.     

Heart rate variability during sleep and the early development of posttraumatic stress disorder

Background

Noradrenergic function has been linked to posttraumatic stress disorder (PTSD) and might have a role in mediating sleep disturbances of the disorder. Our objective was to relate a peripheral manifestation of noradrenergic function, sympathetic nervous system activity as indexed by heart rate variability during sleep, to the development of PTSD in subjects with recent traumatic injuries.

Methods

Subjects who had recall of life-threatening experiences were recruited from one of two regional trauma centers. Select subjects received a polysomnographic recording within 1 month of the trauma. Digitized electrocardiogram recordings were extracted from early and late rapid-eye-movement (REM) and preceding non-REM sleep periods. Autoregression was applied to R-R interval time series to calculate the ratios of low-frequency to high-frequency spectral densities (LF/HF ratios), which index sympathetic activation. Posttraumatic stress disorder status was determined at 2 months.

Results

There was a significant state × group interaction: LF/HF ratios were higher during the REM sleep of the nine subjects who were positive for PTSD symptoms, compared with the 10 subjects who were PTSD negative.

Conclusions

Our findings are consistent with the possibility that increased noradrenergic activity during REM sleep contributes to the development of PTSD.     

Posttraumatic stress disorder is a risk factor for metabolic syndrome in an impoverished urban population

Objective

Metabolic syndrome is associated with elevated risk for cardiovascular disease and diabetes and has increased prevalence in low-income African Americans, which constitutes a significant health disparity. The mechanisms responsible for this disparity remain unclear; the current study investigated the relationship between posttraumatic stress disorder (PTSD) and metabolic syndrome.

Method

We assessed childhood and adult trauma history, major depressive disorder, PTSD and the components of metabolic syndrome in an urban population. We recruited 245 low-socioeconomic-status, primarily African American subjects from general medical clinics in an inner-city hospital.

Results

Trauma exposure was extremely prevalent, with 90.6% of subjects reporting at least one significant trauma and 18.8% of subjects meeting criteria for current PTSD. Metabolic syndrome was also prevalent in this population (33.2%), with significantly higher rates among patients with current PTSD (47.8%, P<.05). After controlling for demographics, smoking history, antipsychotic use, depression and exercise, current PTSD remained the only significant predictor of metabolic syndrome (P=.006).

Conclusions

PTSD is associated with increased rates of metabolic syndrome within a traumatized, impoverished urban population. Further studies should investigate if PTSD treatment may reduce the rates of metabolic syndrome, improve overall health outcomes and decrease health care disparities in minority populations.     

Depression and cognitive deficits in geriatric schizophrenia

Objective

Past reports have found patients with comorbid depression and schizophrenia spectrum disorders exhibit greater deficits in memory and attention compared to schizophrenia spectrum disorder patients without depressive symptoms. However, in contrast to younger schizophrenia patients, the few past studies using cognitive screens to examine the relationship between depression and cognition in inpatient geriatric schizophrenia have found that depressive symptomatology was associated with relatively enhanced cognitive performance. In the current study we examined the relationship between depressive symptoms and cognitive deficits in geriatric schizophrenia spectrum disorder patients (n = 71; mean age = 63.7) on an acute psychiatric inpatient service.

Method

Patients completed a battery of cognitive tests assessing memory, attention and global cognition. Symptom severity was assessed via the PANSS and Calgary Depression Scale for Schizophrenia.

Results

Results revealed that geriatric patients' depression severity predicted enhancement of their attentional and verbal memory performance. Patients' global cognitive functioning and adaptive functioning were not associated with their depression severity.

Conclusion

Contrary to patterns typically seen in younger patients and non-patient groups, increasing depression severity is associated with enhancement of memory and attention in geriatric schizophrenia spectrum disorder patients. Also, diverging from younger samples, depression severity was unassociated with patients adaptive and global cognitive functioning.     

Comorbidity in posttraumatic stress disorder: a structural equation modelling approach

Objective

Posttraumatic stress disorder (PTSD) is associated with high rates of psychiatric comorbidity. Existing theories consider comorbidity as a consequence of PTSD (model 1), PTSD and comorbidity as a consequence of shared factors of vulnerability (model 2), and comorbidity as a consequence of trauma-type specific mechanisms (model 3).

Method

To compare the explanatory value of these models, we assessed PTSD (model 1), sense of coherence (model 2) and satisfaction with health (model 3) and symptoms of anxiety and depression as indicators of comorbidity 5 days (t1) and 6 months (t2) postaccident in 225 injured accident survivors. Structural equation models representing models 1 to 3 were tested separately and combined.

Results

Combined, models 1 and 3 explained 82% of the variance of comorbid symptoms at t2. Posttraumatic stress disorder and satisfaction with health (t2) exerted strong influences on comorbid symptoms.

Conclusion

Comorbidity besides PTSD is best described by an integration of competing explanatory models.     

Posttraumatic stress disorder symptoms in adolescents: risk factors versus resilience moderation

Background

Exposure to community violence and trauma, stress, and childhood abuse and neglect have been identified as risk factors for the development of posttraumatic stress disorder (PTSD) symptoms among adolescents. Although evidence suggests that resilience may moderate the relationship between some of these risk factors and PTSD symptoms, no studies to date have examined these risk factors collectively.

Aims

Our first aim was to examine the relationship between exposure to community violence, childhood abuse and neglect, perceived stress, and PTSD symptoms. Our second aim was to examine the extent to which resilience moderated the relationship between risk factors and PTSD symptoms.

Method

A convenience sample of 787 participants was drawn from 5 public secondary schools in the Cape Town metropole of South Africa. The participants were invited to complete a battery of questionnaires on a single occasion.

Results

Of the participants, 48.3% were Black, 58.6% were female, and 31.6% were in grade 8. After controlling for covariates, we found that exposure to community violence, perceived stress, and childhood abuse and neglect together accounted for 33.4% of the variance in PTSD symptoms (F_8,778 = 71.06, P < .001). Nevertheless, resilience moderated the relationship between childhood abuse and symptoms of PTSD (β = .09, t₇₈₆ = 2.88, P < .001), where the independent effect of childhood abuse and neglect on PTSD symptoms was significantly reduced with increasing resilience. Resilience did not, however, interact with exposure to community violence or perceived levels of stress to influence PTSD symptoms.

Conclusion

High levels of exposure to community violence, perceived stress, and childhood abuse and neglect may contribute to the development of PTSD symptoms in South African adolescents. However, high levels of resilience may buffer the negative effects of childhood abuse and neglect.     

Enhancing the population impact of collaborative care interventions: mixed method development and implementation of stepped care targeting posttraumatic stress disorder and related comorbidities after acute trauma

Objective

The objective of the study was to develop and implement a stepped collaborative care intervention targeting posttraumatic stress disorder (PTSD) and related comorbidities to enhance the population impact of early trauma-focused interventions.

Method

We describe the design and implementation of the Trauma Survivors Outcomes and Support study. An interdisciplinary treatment development team was composed of trauma surgical, clinical psychiatric and mental health services “change agents” who spanned the boundaries between frontline trauma center clinical care and acute care policy. Mixed method clinical epidemiologic and clinical ethnographic studies informed the development of PTSD screening and intervention procedures.

Results

Two hundred seven acutely injured trauma survivors with high early PTSD symptom levels were randomized into the study. The stepped collaborative care model integrated care management (i.e., posttraumatic concern elicitation and amelioration, motivational interviewing and behavioral activation) with cognitive behavioral therapy and pharmacotherapy targeting PTSD. The model was feasibly implemented by frontline acute care masters in social work and nurse practioner providers.

Conclusions

Stepped care protocols targeting PTSD may enhance the population impact of early interventions developed for survivors of individual and mass trauma by extending the reach of collaborative care interventions to acute care medical settings and other nonspecialty posttraumatic contexts.     

Basal and dexamethasone suppressed salivary cortisol concentrations in a community sample of patients with posttraumatic stress disorder

Background

Posttraumatic stress disorder (PTSD) has been associated with lower concentrations of cortisol and enhanced suppression of cortisol by dexamethasone, although discrepancies exist among reports. The objective of the study was to determine the pattern of cortisol responses in patients seeking treatment for PTSD resulting from a variety of traumatic experiences and to test whether cortisol responses are significantly related to childhood trauma, severity of symptoms, or length of time since trauma.

Methods

Salivary cortisol was measured at 8 am, 4 pm, and 10 pm on 2 consecutive days before and after a 10 pm dose of .5 mg dexamethasone in 17 psychotropic medication and substance-free subjects with PTSD and 17 matched control subjects.

Results

Repeated-measures analysis of variance (ANOVA) of the baseline salivary cortisol concentrations demonstrated a significant effect for group with higher concentrations in the PTSD group but no significant differences in responses to dexamethasone. The presence of childhood abuse did not significantly affect salivary cortisol concentrations, and there was no correlation between predexamethasone cortisol and either the severity of PTSD symptoms or the time since the index trauma.

Conclusions

Neither low basal concentrations nor enhanced suppression of cortisol are consistent markers of a PTSD diagnosis.     

Personality disorders associated with full and partial posttraumatic stress disorder in the U.S. population: results from Wave 2 of the National Epidemiologic Survey on Alcohol and Related Conditions

Background

While it is well known that personality disorders are associated with trauma exposure and PTSD, limited nationally representative data are available on DSM-IV personality disorders that co-occur with posttraumatic stress disorder (PTSD) and partial PTSD.

Methods

Face-to-face interviews were conducted with 34,653 adults participating in the Wave 2 National Epidemiologic Survey on Alcohol and Related Conditions. Logistic regression analyses controlling for sociodemographics and additional psychiatric comorbidity evaluated associations of PTSD and partial PTSD with personality disorders.

Results

Prevalence rates of lifetime PTSD and partial PTSD were 6.4% and 6.6%, respectively. After adjustment for sociodemographic characteristics and additional psychiatric comorbidity, respondents with full PTSD were more likely than trauma controls to meet criteria for schizotypal, narcissistic, and borderline personality disorders (ORs = 2.1-2.5); and respondents with partial PTSD were more likely than trauma controls to meet diagnostic criteria for borderline (OR = 2.0), schizotypal (OR = 1.8), and narcissistic (OR = 1.6) PDs. Women with PTSD were more likely than controls to have obsessive-compulsive PD. Women with partial PTSD were more likely than controls to have antisocial PD; and men with partial PTSD were less likely than women with partial PTSD to have avoidant PD.

Conclusions

PTSD and partial PTSD are associated with borderline, schizotypal, and narcissistic personality disorders. Modestly higher rates of obsessive-compulsive PD were observed among women with full PTSD, and of antisocial PD among women with partial PTSD.     

Association of trauma exposure with psychiatric morbidity in military veterans who have served since September 11, 2001

Objective

This study examined the association of lifetime traumatic stress with psychiatric diagnostic status and symptom severity in veterans serving in the US military after 9/11/01.

Method

Data from 356 US military veterans were analyzed. Measures included a standardized clinical interview measure of psychiatric disorders, and paper-and-pencil assessments of trauma history, demographic variables, intellectual functioning, posttraumatic stress disorder (PTSD) symptoms, depression, alcohol misuse, and global distress.

Results

Ninety-four percent of respondents reported at least one traumatic stressor meeting DSM-IV criterion A for PTSD (i.e., life threatening event to which the person responded with fear, helplessness or horror), with a mean of four criterion A traumas. Seventy-one percent reported serving in a war-zone, with 50% reporting occurrence of an event meeting criterion A. The rate of current psychiatric disorder in this sample was: 30% PTSD, 20% major depressive disorder, 6% substance abuse or dependence and 10% for the presence of other Axis I psychiatric disorders. After accounting for demographic covariates and combat exposure, childhood physical assault and accident/disasters were most consistently associated with increased likelihood of PTSD. However, PTSD with no comorbid major depressive disorder or substance use disorder was predicted only by combat exposure and adult physical assault. Medical/unexpected-death trauma and adult physical assault were most consistently associated with more severe symptomatology.

Conclusions

Particular categories of trauma were differentially associated with the risk of psychiatric diagnosis and current symptom severity. These findings underscore the importance of conducting thorough assessment of multiple trauma exposures when evaluating recently post-deployed veterans.     

Assessing the structure and meaningfulness of the dissociative subtype of PTSD

Purpose

Studies conducted in the USA, Canada and Denmark have supported the existence of the dissociative PTSD subtype, characterized primarily by symptoms of depersonalization and derealization. The current study aimed to examine the dissociative PTSD subtype in an Eastern European, predominantly female (83.16%) sample, using an extended set of dissociative symptoms.

Methods

A latent profile analysis was applied to the PTSD and dissociation data from 689 trauma-exposed university students from Slovakia.

Results

Four latent profiles of varying PTSD and dissociation symptomatology were uncovered. They were named non-symptomatic, moderate PTSD, high PTSD and dissociative PTSD. The dissociative PTSD profile showed elevations on depersonalization and derealization, but also the alternative dissociative indicators of gaps in awareness and memory, sensory misperceptions and cognitive and behavioural re-experiencing. The core PTSD symptoms of ‘memory impairment’ and ‘reckless or self-destructive behaviour’ were also significantly elevated in the dissociative PTSD profile. Moreover, anxiety and anger predicted membership in the dissociative PTSD profile.

Conclusion

The results provide support for the proposal that the dissociative PTSD subtype can be characterized by a variety of dissociative symptoms.

     

Illusory touch and tactile perception in somatoform dissociators

Objective

The psychological mechanisms of somatoform dissociation (i.e., pseudoneurological symptoms) are poorly understood. This study evaluated recent theoretical predictions regarding the role of tactile perception in the development of somatoform dissociative symptoms.

Methods

Eighty nonclinical participants scoring either high or low on the Somatoform Dissociation Questionnaire (SDQ-20) completed the Somatic Signal Detection Task (SSDT), a novel perceptual paradigm designed to simulate the occurrence of somatoform symptoms in the laboratory. Prior to the SSDT, participants completed a memory task designed to produce either minimal or maximal activation of tactile representations in memory.

Results

The high SDQ-20 group exhibited a more liberal response criterion (c) on the SSDT than the low SDQ-20 group after controlling for negative affectivity, somatosensory amplification and depression. This effect was mainly attributable to an increased number of false alarms (i.e., illusory experiences of touch) in the high SDQ-20 group rather than an increased hit rate. General perceptual ability (i.e., tactile sensitivity) was comparable between the two groups. The memory manipulation had no effect on SSDT performance.

Conclusions

Somatoform dissociators appear more likely to experience illusory perceptual events under conditions of sensory ambiguity than nondissociators, despite comparable perceptual abilities more generally. These findings support theories that identify distorted perceptual processing as a feature of somatoform dissociation. The SSDT has potential as a tool for further research in this area.     

Defining medical posttraumatic stress among young adult survivors in the Childhood Cancer Survivor Study

Objective

To examine the implications of use of differential thresholds for studying medical Posttraumatic Stress Disorder (PTSD).

Methods

Self-report data from 6,542 young adult survivors of childhood cancer and 374 of their siblings were used to create clearly differentially defined groups to compare prevalence, correlations and predictors of posttraumatic stress.

Results

Prevalence of posttraumatic stress in survivors compared to siblings differed by definition used, ranging from an odds ratio of 4.21 (95% CI 2.11-8.38) when posttraumatic stress was defined as meeting full symptoms plus functional impairment to 1.42 (95% CI 0.79-2.56) for partial symptoms with functional impairment. Re-experiencing symptoms did not substantially contribute to the ability to identify functional impairment and emotional distress. Although most of the variables associated with posttraumatic stress symptoms and impairment were consistent across definitions of PTSD, marital status and employment demonstrated nonproportional relationships.

Conclusions

Choice of the definition used in studying posttraumatic stress after serious illness alters not only epidemiological findings, but also associations with correlates and predictors. This is important in the current debate about the criteria for PTSD in the upcoming DSMV. Further study is needed to determine if these findings are applicable to people exposed to other types of traumatic events.     

Family psychiatric history, peritraumatic reactivity, and posttraumatic stress symptoms: A prospective study of police

Background

Family history of psychiatric and substance use disorders has been associated with posttraumatic stress disorder (PTSD) in cross-sectional studies.

Method

Using a prospective design, we examined the relationships of family history of psychiatric and substance use disorders to posttraumatic stress symptoms in 278 healthy police recruits. During academy training, recruits were interviewed on family and personal psychopathology, prior cumulative civilian trauma exposure, and completed self-report questionnaires on nonspecific symptoms of distress and alcohol use. Twelve months after commencement of active duty, participants completed questionnaires on critical incident exposure over the previous year, peritraumatic distress to the worst critical incident during this time, and posttraumatic stress symptoms.

Results

A path model indicated: (1) family loading for mood and anxiety disorders had an indirect effect on posttraumatic stress symptoms at 12 months that was mediated through peritraumatic distress to the officer’s self-identified worst critical incident, (2) family loading for substance use disorders also predicted posttraumatic stress symptoms at 12 months and this relationship was mediated through peritraumatic distress.

Conclusion

These findings support a model in which family histories of psychopathology and substance abuse are pre-existing vulnerability factors for experiencing greater peritraumatic distress to critical incident exposure which, in turn, increases the risk for development of symptoms of posttraumatic stress disorder. Replication in other first responders, military and civilians will be important to determine generalizability of these findings.