Posttraumatic Stress Disorder Symptom Dimensions Research Articles

Trauma exposure, contextual stressors, and PTSD symptoms: patterns in racially and ethnically diverse, low-income postpartum women.

Racial, ethnic, and socioeconomic disparities persist in posttraumatic stress disorder (PTSD), which are partly attributed to minoritized women being trauma-exposed, while also contending with harmful contextual stressors. However, few have used analytic strategies that capture the interplay of these experiences and their relation to PTSD. The current study used a person-centered statistical approach to examine heterogeneity in trauma and contextual stress exposure, and their associations with PTSD and underlying symptom dimensions, in a diverse sample of low-income postpartum women. Using a community-based sample of Black, Hispanic/Latina, and White postpartum women recruited from five U.S. regions (n = 1577), a latent class analysis generated profiles of past-year exposure to traumatic events and contextual stress at one month postpartum. Regression analyses then examined associations between class membership and PTSD symptom severity at six months postpartum as a function of race/ethnicity. A four-class solution best fit the data, yielding High Contextual Stress, Injury/Illness, Violence Exposure, and Low Trauma/Contextual Stress classes. Compared to the Low Trauma/Contextual Stress class, membership in any of the other classes was associated with greater symptom severity across nearly all PTSD symptom dimensions (all ps < 0.05). Additionally, constellations of exposures were differentially linked to total PTSD symptom severity, reexperiencing, and numbing PTSD symptoms across racial/ethnic groups (ps < 0.05). A person-centered approach to trauma and contextual stress exposure can capture heterogeneity of experiences in diverse, low-income women. Moreover, racially/ethnically patterned links between traumatic or stressful exposures and PTSD symptom dimensions have implications for screening and intervention in the perinatal period.

Skin Conductance Reactivity as a Predictor of Stroke-induced Posttraumatic Stress Disorder Symptoms: A Dimensional Approach.

Posttraumatic stress disorder (PTSD) symptoms can develop following acute, life-threatening medical events. This study explores a potential biomarker of PTSD risk that is novel to a medical trauma population: a noninvasive, mobile skin conductance (SC) measurement. Participants (N=64) were enrolled in-hospital following a stroke or transient ischemic attack (TIA). Mobile measurement of SC reactivity to recalling the stroke/TIA traumatic event was conducted at hospital bedside in the days following the stroke/TIA. PTSD symptoms that developed in response to the stroke/TIA were measured at 1-month follow-up. We tested the association between SC reactivity and total 1-month PTSD symptoms, as well as PTSD symptom dimensions of fear and dysphoria. In unadjusted analyses, there were significant positive associations between in-hospital SC reactivity to recalling the stroke/TIA traumatic event and higher-order fear-related symptoms (r=.30, p=.016), as well as lower-order fear-related symptoms of anxious arousal (r=.27, p=.035) and avoidance (r=.25, p=.043) at 1 month. Associations between SC reactivity and the fear, anxious arousal, and avoidance symptom dimensions remained significant in multivariable regression models that adjusted for relevant covariates including age, gender, stroke severity, medical comorbidity, and psychosocial factors. Although there was a positive association observed between SC reactivity to recalling the stroke/TIA event and total PTSD symptom severity at 1-month follow-up, it did not reach the level of statistical significance (r=.23, p=.070). Further, no significant association was detected for dysphoria-related symptoms (r=.11, p=.393). This is the first study to test the prospective association of SC reactivity with PTSD symptom development following a medical trauma. The findings indicate that mobile measures of SC reactivity may be useful for in-hospital identification of individuals at risk for fear-related PTSD symptom development following a medical event and highlight the potential mechanisms involved in the development of these symptoms following a medical event.

Altered gene expression and PTSD symptom dimensions in World Trade Center responders.

Despite experiencing a significant trauma, only a subset of World Trade Center (WTC) rescue and recovery workers developed posttraumatic stress disorder (PTSD). Identification of biomarkers is critical to the development of targeted interventions for treating disaster responders and potentially preventing the development of PTSD in this population. Analysis of gene expression from these individuals can help in identifying biomarkers of PTSD. We established a well-phenotyped sample of 371 WTC responders, recruited from a longitudinal WTC responder cohort using stratified random sampling, by obtaining blood, self-reported and clinical interview data. Using bulk RNA-sequencing from whole blood, we examined the association between gene expression and WTC-related PTSD symptom severity on (i) highest lifetime Clinician-Administered PTSD Scale (CAPS) score, (ii) past-month CAPS score, and (iii) PTSD symptom dimensions using a 5-factor model of re-experiencing, avoidance, emotional numbing, dysphoric arousal and anxious arousal symptoms. We corrected for sex, age, genotype-derived principal components and surrogate variables. Finally, we performed a meta-analysis with existing PTSD studies (total N = 1016), using case/control status as the predictor and correcting for these variables. We identified 66 genes significantly associated with total highest lifetime CAPS score (FDR-corrected p < 0.05), and 31 genes associated with total past-month CAPS score. Our more granular analyses of PTSD symptom dimensions identified additional genes that did not reach statistical significance in our analyses with total CAPS scores. In particular, we identified 82 genes significantly associated with lifetime anxious arousal symptoms. Several genes significantly associated with multiple PTSD symptom dimensions and total lifetime CAPS score (SERPINA1, RPS6KA1, and STAT3) have been previously associated with PTSD. Geneset enrichment of these findings has identified pathways significant in metabolism, immune signaling, other psychiatric disorders, neurological signaling, and cellular structure. Our meta-analysis revealed 10 genes that reached genome-wide significance, all of which were downregulated in cases compared to controls (CIRBP, TMSB10, FCGRT, CLIC1, RPS6KB2, HNRNPUL1, ALDOA, NACA, ZNF429 and COPE). Additionally, cellular deconvolution highlighted an enrichment in CD4 T cells and eosinophils in responders with PTSD compared to controls. The distinction in significant genes between total lifetime CAPS score and the anxious arousal symptom dimension of PTSD highlights a potential biological difference in the mechanism underlying the heterogeneity of the PTSD phenotype. Future studies should be clear about methods used to analyze PTSD status, as phenotypes based on PTSD symptom dimensions may yield different gene sets than combined CAPS score analysis. Potential biomarkers implicated from our meta-analysis may help improve therapeutic target development for PTSD.

Mapping the transcriptomics landscape of post-traumatic stress disorder symptom dimensions in World Trade Center responders

Gene expression has provided promising insights into the pathophysiology of post-traumatic stress disorder (PTSD); however, specific regulatory transcriptomic mechanisms remain unknown. The present study addressed this limitation by performing transcriptome-wide RNA-Seq of whole-blood samples from 226 World Trade Center responders. The investigation focused on differential expression (DE) at the gene, isoform, and for the first time, alternative splicing (AS) levels associated with the symptoms of PTSD: total burden, re-experiencing, avoidance, numbing, and hyperarousal subdimensions. These symptoms were associated with 76, 1, 48, 15, and 49 DE genes, respectively (FDR < 0.05). Moreover, they were associated with 103, 11, 0, 43, and 32 AS events. Avoidance differed the most from other dimensions with respect to DE genes and AS events. Gene set enrichment analysis (GSEA) identified pathways involved in inflammatory and metabolic processes, which may have implications in the treatment of PTSD. Overall, the findings shed a novel light on the wide range of transcriptomic alterations associated with PTSD at the gene and AS levels. The results of DE analysis associated with PTSD subdimensions highlights the importance of studying PTSD symptom heterogeneity.

Interpersonal Functioning and Trauma: The Role of Empathy in Moderating the Association of PTSD and Interpersonal Functioning

Research demonstrates consistent associations between symptoms of posttraumatic stress disorder (PTSD) and reductions in interpersonal functioning. Moderators of this association, however, remain relatively unexplored. The current study aimed to examine the extent to which aspects of empathic responding may influence the relation between PTSD symptom dimensions and interpersonal functioning in students exposed to significant trauma. Participants (N = 94, 85.1% female, 86.2% White/Non-Hispanic) completed an initial screening to assess for trauma exposure and associated symptoms of PTSD. Interpersonal functioning and dimensions of empathic responding were measured using a series of self-report and lab-based tasks. Hierarchical regression models provided evidence for a consistent association between post-trauma arousal-reactivity and reductions in interpersonal functioning. Results also indicated a moderating effect of affective empathy (β = −.37, p = .010, f2 = .086). Simple slopes and Johnson-Neyman plots identified an association between arousal-reactivity and functioning at low (β = 1.57, p < .001, f2 = .301) versus high (β = .31, p = .417, f2 = .008) levels of empathic response to a positively valenced film. Results offer preliminary support for a potential buffering effect of affective empathy on interpersonal functioning in individuals reporting chronic, trauma-related symptoms.

Associations Between Baseline Total PTSD Symptom Severity, Specific PTSD Symptoms, and 3-Month Quality of Life in Neurologically Intact Neurocritical Care Patients and Informal Caregivers.

The objective is to pilot test the feasibility of assessing severity of posttraumatic stress disorder (PTSD) symptoms, as well as specific lower-order PTSD symptoms, experienced during neurological intensive care unit (neuro-ICU) admission and their relationship with 3-month quality of life (QoL) scores in multiple domains (i.e., physical, psychological, social, and environmental) in both patients and caregivers. Between 2015 and 2016, we enrolled neurologically intact patients and informal caregivers of patients who reported demographics and PTSD symptoms (PTSD Checklist-Specific; PCL-S) during neuro-ICU admission and completed a QoL assessment (World Health Organization Quality of Life;WHOQOL-BREF) 3months later. Clinical data were extracted from medical records. We ran two bivariate correlation matrices among PTSD symptom dimensions in patients and caregivers. Then, we used multiple linear regression to examine the prospective association of total PCL-S scores with each QoL domain in both patients and caregivers after adjusting for clinically important variables. Next, we explored differential associations between the 4 PTSD symptom dimensions and each QoL domain in both patients and caregivers, adjusting for sex and age. A total of 70 patients (45.7% women, 84.3% white, mean age 52.08years) and 64 caregivers (64.1% women, 90.6% white, mean age 53.12years) were included. PTSD symptom dimensions were moderately strongly correlated among patients (r = 0.65-0.79, p < 0.001) and caregivers (r = 0.55-0.78, p < 0.001). For both patients and caregivers, greater PTSD symptom severity was prospectively associated with lower QoL in all domains (β = -0.289 to - 0.622; p < 0.05). Our exploratory analysis revealed that greater numbing symptoms were associated with lower psychological QoL in patients (β: - 0.397, p = 0.038), and lower physical (β: - 0.409, p = 0.014), psychological (β: - 0.519, p = 0.001), and social QoL (β: -0.704, p < 0.001) in caregivers. Greater re-experiencing symptoms were associated with lower physical QoL in both patients (β: - 0.422, p = 0.047) and caregivers (β: - 0.4, p = 0.041). Our preliminary results indicated that greater severity of PTSD symptoms, and specifically numbing and re-experiencing symptoms, experienced by patients and caregivers during neuro-ICU admission was predictive of worse 3-month QoL. Continued study is needed to identify treatment targets for PTSD and QoL in this population.

Distress Variance and Specificity of Symptom Dimensions in Posttraumatic Stress Disorder: a Quadripartite Perspective

The relation of posttraumatic stress disorder (PTSD) to other forms of psychopathology is complex as diagnostic criteria include symptoms of both mood- and anxiety-related conditions. Drawing from Watson’s (2009) quadripartite model of comorbidity, the current study examined (a) the association of PTSD symptom dimensions with indices of generalized distress, (b) the specificity of PTSD symptom dimensions for core aspects of anxiety and depression, and (c) the unique associations of symptom dimensions with markers of positive emotionality, somatic arousal, generalized distress, and cumulative trauma history. Confirmatory analyses were used to model symptom dimensions in help-seeking survivors of intimate partner violence (N = 238; 51.7% White/Non-Hispanic). Latent markers of positive emotionality, somatic arousal, and generalized distress were also estimated. A 3-factor version of the Simms et al. (2002) Dysphoria model was identified as a preferred solution, with Intrusion and Avoidance criteria collapsed on a common dimension. Analyses revealed moderate correlations of generalized distress with Intrusion-Avoidance, Dysphoria, and Hyperarousal dimensions (r = .30–.38). Intrusion-Avoidance and Hyperarousal factors evidenced specificity for the core aspects of anxiety while Dysphoria demonstrated an association with the characteristic features of depression when controlling for nonspecific distress. Hyperarousal was the only symptom dimension holding a unique association with cumulative trauma controlling for somatic arousal, positive emotionality, and generalized distress. Results offer preliminary support for the specificity of core dimensions of PTSD above and beyond the influence of nonspecific distress.

Cortical thickness reduction in combat exposed U.S. veterans with and without PTSD

We investigated the extent of cortical thinning in U.S. Veterans exposed to combat who varied in the severity of their posttraumatic stress disorder (PTSD) symptoms. In addition, we explored the neural correlates of PTSD symptom dimensions and the interactive effects of combat exposure and PTSD upon cortical thickness. Sixty-nine combat exposed Veterans completed high-resolution magnetic resonance imaging (MRI) scans to estimate cortical thickness. The Clinician Administered PTSD Scale (CAPS) and Combat Exposure Scale (CES) assessments were completed to measure current PTSD and historical combat severity, respectively. PTSD symptom dimensions (numbing, avoidance, reexperiencing, anxious arousal, and dysphoric arousal) were studied. Vertex-wise whole cerebrum analyses were conducted. We found widespread negative correlations between CAPS severity and cortical thickness, particularly within the prefrontal cortex. This prefrontal correlation remained significant after controlling for depression severity, medication status, and other potential confounds. PTSD dimensions, except anxious arousal, negatively correlated with cortical thickness in various unique brain regions. CES negatively correlated with cortical thickness in the left lateral prefrontal, regardless of PTSD diagnosis. A significant interaction between CES and PTSD diagnosis was found, such that CES negatively correlated with cortical thickness in the non-PTSD, but not in the PTSD, participants. The results underscore the severity of cortical thinning in U.S. Veterans suffering from high level of PTSD symptoms, as well as in Veterans with no PTSD diagnosis but severe combat exposure. The latter finding raises considerable concerns about a concealed injury potentially related to combat exposure in the post-9/11 era.

Post-traumatic stress disorder dimensions and asthma morbidity in World Trade Center rescue and recovery workers

ABSTRACTObjective: Using data from a cohort of World Trade Center (WTC) rescue and recovery workers with asthma, we assessed whether meeting criteria for post-traumatic stress disorder (PTSD), sub-threshold PTSD, and for specific PTSD symptom dimensions are associated with increased asthma morbidity. Methods: Participants underwent a Structured Clinical Interview for Diagnostic and Statistical Manual to assess the presence of PTSD following DSM-IV criteria during in-person interviews between December 2013 and April 2015. We defined sub-threshold PTSD as meeting criteria for two of three symptom dimensions: re-experiencing, avoidance, or hyper-arousal. Asthma control, acute asthma-related healthcare utilization, and asthma-related quality of life data were collected using validated scales. Unadjusted and multiple regression analyses were performed to assess the relationship between sub-threshold PTSD and PTSD symptom domains with asthma morbidity measures. Results: Of the 181 WTC workers with asthma recruited into the study, 28% had PTSD and 25% had sub-threshold PTSD. Patients with PTSD showed worse asthma control, higher rates of inpatient healthcare utilization, and poorer asthma quality of life than those with sub-threshold or no PTSD. After adjusting for potential confounders, among patients not meeting the criteria for full PTSD, those presenting symptoms of re-experiencing exhibited poorer quality of life (p = 0.003). Avoidance was associated with increased acute healthcare use (p = 0.05). Sub-threshold PTSD was not associated with asthma morbidity (p > 0.05 for all comparisons). Conclusions: There may be benefit in assessing asthma control in patients with sub-threshold PTSD symptoms as well as those with full PTSD to more effectively identify ongoing asthma symptoms and target management strategies.

Giant Pleomorphic Adenoma of the Parotid Gland

Posttraumatic stress disorder (PTSD) symptoms are common in the immediate aftermath of a trauma, but it is their persistence over time that leads to a diagnosis. This pattern highlights the critical role of symptom maintenance to understanding and treating the disorder. Relatively few studies have explored whether PTSD symptoms may be interacting or triggering one another to worsen and maintain the disorder, a dynamic we refer to as “symptom cascades.” Additionally, little work has tested in real-time how other maintenance factors, such as stress, contribute to such events in daily life.The present study in a group (N = 202) of World Trade Center (WTC) responders oversampled for PTSD tested day-to-day temporal associations among PTSD symptom dimensions (i.e., intrusions, avoidance, numbing, and hyperarousal) and stress across one week.Longitudinal models found hyperarousal on a given day predicted increased PTSD symptoms the next day, with the effect sizes almost double compared to other symptom dimensions or daily stress. Intrusions, in contrast, showed little prospective predictive effects, but instead were most susceptible to the effects from other symptoms the day before. Avoidance and numbing showed weaker bidirectional effects.Findings are from a unique population and based on naturalistic observation.Results are consistent with the idea of symptom cascades, they underscore hyperarousal's strong role in forecasting short-term increases in PTSD (even more than stress per se) and they raise the prospect of highly specific ecological momentary interventions to potentially disrupt PTSD maintenance in daily life.

Distinct intrinsic network connectivity patterns of post-traumatic stress disorder symptom clusters.

Post-traumatic stress disorder (PTSD) is considered a multidimensional disorder, with distinct symptom clusters including re-experiencing, avoidance/numbing, hyperarousal, and most recently depersonalization/derealization. However, the extent of differing intrinsic network connectivity underlying these symptoms has not been fully investigated. We therefore investigated the degree of association between resting connectivity of the salience (SN), default mode (DMN), and central executive (CEN) networks and PTSD symptom severity. Using resting-state functional MRI data from PTSD participants (n = 21), we conducted multivariate analyses to test whether connectivity of extracted independent components varied as a function of re-experiencing, avoidance/numbing, hyperarousal, and depersonalization/derealization. Hyperarousal symptoms were associated with reduced connectivity of posterior insula/superior temporal gyrus within SN [peak Montréal Neurological Institute (MNI): -44, -8, 0, t = -4.2512, k = 40]. Depersonalization/derealization severity was associated with decreased connectivity of perigenual anterior cingulate/ventromedial prefrontal cortex within ventral anterior DMN (peak MNI: 8, 40, -4; t = -3.8501; k = 15) and altered synchrony between two DMN components and between DMN and CEN. Our results are consistent with prior research showing intrinsic network disruptions in PTSD and imply heterogeneous connectivity patterns underlying PTSD symptom dimensions. These findings suggest possible biomarkers for PTSD and its dissociative subtype.

Elucidating dimensions of posttraumatic stress symptoms and their functional correlates in disaster-exposed adolescents

The aim of this study was to elucidate the dimensional structure of posttraumatic stress disorder (PTSD) and potential moderators and functional correlates of this structure in disaster-affected adolescents. A population-based sample of 2000 adolescents aged 12–17 years (M = 14.5 years; 51% female) completed interviews on post-tornado PTSD symptoms, substance use, and parent–adolescent conflict between 4 and 13 months (M = 8.8, SD = 2.6) after tornado exposure. Confirmatory factor analyses revealed that all models fit well but a 5-factor dysphoric arousal model provided a statistically significantly better representation of adolescent PTSD symptoms compared to 4-factor dysphoria and emotional numbing models. There was evidence of measurement invariance of the dysphoric arousal model across gender and age, although girls and older adolescents aged 15–17 years had higher mean scores than boys and younger adolescents aged 12–14 years, respectively, on some PTSD dimensions. Differential magnitudes of association between PTSD symptom dimensions and functional correlates were observed, with emotional numbing symptoms most strongly positively associated with problematic substance use since the tornado, and dysphoric arousal symptoms most strongly positively associated with parent–adolescent conflict; both correlations were significantly larger than the corresponding correlations with anxious arousal. Taken together, these results suggest that the dimensional structure of tornado-related PTSD symptomatology in adolescents is optimally characterized by five separate clusters of re-experiencing, avoidance, numbing, dysphoric arousal, and anxious arousal symptoms, which showed unique associations with functional correlates. Findings emphasize that PTSD in disaster-exposed adolescents is not best conceptualized as a homogenous construct and highlight potential differential targets for post-disaster assessment and intervention.

DSM-5 PTSD's symptom dimensions and relations with major depression's symptom dimensions in a primary care sample

Existing literature indicates significant comorbidity between posttraumatic stress disorder (PTSD) and major depression. We examined whether PTSD’s dysphoria and mood/cognitions factors, conceptualized by the empirically supported four-factor DSM-5 PTSD models, account for PTSD's inherent relationship with depression. We hypothesized that depression's somatic and non-somatic factors would be more related to PTSD's dysphoria and mood/cognitions factors than other PTSD model factors. Further, we hypothesized that PTSD's arousal would significantly mediate relations between PTSD's dysphoria and somatic/non-somatic depression. Using 181 trauma-exposed primary care patients, confirmatory factor analyses (CFA) indicated a well-fitting DSM-5 PTSD dysphoria model, DSM-5 numbing model and two-factor depression model. Both somatic and non-somatic depression factors were more related to PTSD's dysphoria and mood/cognitions factors than to re-experiencing and avoidance factors; non-somatic depression was more related to PTSD's dysphoria than PTSD's arousal factor. PTSD's arousal did not mediate the relationship between PTSD's dysphoria and somatic/non-somatic depression. Implications are discussed.

PTSD symptom dimensions and their relationship to functioning in World Trade Center responders

Post-traumatic stress disorder (PTSD) symptoms are common among responders to the 9/11 attacks on the World Trade Center and can lead to impairment, yet it is unclear which symptom dimensions are responsible for poorer functioning. Moreover, how best to classify PTSD symptoms remains a topic of controversy. The present study tested competing models of PTSD dimensions and then assessed which were most strongly associated with social/occupational impairment, depression, and alcohol abuse. World Trade Center responders (n=954) enrolled in the Long Island site of the World Trade Center Health Program between 2005 and 2006 were administered standard self-report measures. Confirmatory factor analysis confirmed the superiority of four-factor models of PTSD over the DSM-IV three-factor model. In selecting between four-factor models, evidence was mixed, but some support emerged for a broad dysphoria dimension mapping closely onto depression and contributing strongly to functional impairment. This study confirmed in a new population the need to revise PTSD symptom classification to reflect four dimensions, but raises questions about how symptoms are categorized. Results suggest that targeted treatment of symptoms may provide the most benefit, and that treatment of dysphoria-related symptoms in disaster relief workers may have the most benefit for social and occupational functioning.

Exposure to Interpersonal Violence as a Predictor of PTSD Symptomatology in Domestic Violence Survivors

This study examines the interrelationships between childhood abuse, exposure to maternal domestic violence, and posttraumatic stress disorder (PTSD) symptomatology in a multiethnic sample of 111 adult female residents of a domestic violence (DV) shelter. Participants completed structured interviews about the DV and their prior violence exposure, as well as the Impact of Event Scale-Revised. As hypothesized, there was high co-occurrence between exposure to maternal DV and childhood physical and sexual abuse, and the frequency of lifetime violence exposure predicted PTSD symptomatology. A series of multiple regressions indicated a more complex pattern of relationships, in which specific forms of prior violence exposure predicted different PTSD symptom dimensions. A history of witnessing maternal DV predicted intrusion symptoms, and a history of childhood sexual abuse predicted hyperarousal symptoms. Ethnicity was not related to levels of violence exposure or to PTSD symptoms. Clinical implications of the findings are discussed.

The relations of PTSD symptoms to alcohol use and coping drinking in volunteers who responded to the Swissair Flight 111 airline disaster

We investigated the effects of the 1998 Swissair Flight 111 (SA 111) disaster on a variety of indices of alcohol use among volunteer responders. We retrospectively administered standardized questionnaires and a semi-structured interview to 13 volunteer disaster workers recruited from the community. According to the interview, 54% of the volunteers were exposed to human remains. According to Modified Post-Traumatic Stress Disorder (PTSD) Symptoms Scale responses, 46% met DSM-IV criteria for PTSD. Frequency and severity of PTSD symptoms, but not human remains exposure, per se, were positively correlated with coping-motivated drinking (but not social or mood enhancement drinking) and with alcohol use to forget. The re-experiencing and hyper-arousal PTSD symptom dimensions showed the strongest and most consistent correlations with the alcohol use indices. We discuss ways in which the information gleaned from this sample can be used to improve disaster response planning to minimize the probability of maladaptive coping drinking among volunteers.

Penn Inventory for Posttraumatic Stress Disorder: Psychometric properties.

This article reports a 3-phase study to develop and validate the Penn Inventory for Posttraumatic Stress Disorder (PTSD), a 26-item self-report measure of the severity of PTSD. In Phase 1, using a sample (n=83) selected in 4 different groups, the inventory showed high internal consistency, test-retest reliability, and validity in relation to a structured clinical PTSD diagnosis, measures of combat exposure, and measures of PTSD symptom dimensions. Phase 2 cross-validated the initial findings on a second sample (n=98), yielding results comparable to those of Phase 1, including measures of sensitivity and specificity. Phase 3, using a new sample (n=76), extended the findings to general veteran psychiatric admissions and civilian survivors of the Piper Alpha oil rig disaster, and used as criterion measures the Mississippi Scale for Combat-related PTSD among the veteran groups and the Impact of Event Scale in the civilian group