Confirmatory factor analysis of the PTSD Checklist and the Clinician-Administered PTSD Scale in disaster workers exposed to the World Trade Center Ground Zero.

Although posttraumatic stress disorder (PTSD) factor analytic research has yielded little support for the DSM-IV 3-factor model of reexperiencing, avoidance, and hyperarousal symptoms, no clear consensus regarding alternative models has emerged. One possible explanation is differential instrumentation across studies. In the present study, the authors used confirmatory factor analysis to compare a self-report measure, the PTSD Checklist (PCL), and a structured clinical interview, the Clinician-Administered PTSD Scale (CAPS), in 2,960 utility workers exposed to the World Trade Center Ground Zero site. Although two 4-factor models fit adequately for each measure, the latent structure of the PCL was slightly better represented by correlated reexperiencing, avoidance, dysphoria, and hyperarousal factors, whereas that of the CAPS was slightly better represented by correlated reexperiencing, avoidance, emotional numbing, and hyperarousal factors. After accounting for method variance, the model specifying dysphoria as a distinct factor achieved slightly better fit. Patterns of correlations with external variables provided additional support for the dysphoria model. Implications regarding the underlying structure of PTSD are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Confirmatory factor analyses of posttraumatic stress symptoms in deployed and nondeployed veterans of the Gulf War.

Confirmatory factor analysis was used to compare 6 models of posttraumatic stress disorder (PTSD) symptoms, ranging from 1 to 4 factors, in a sample of 3,695 deployed Gulf War veterans (N = 1,896) and nondeployed controls (N = 1,799). The 4 correlated factors-intrusions, avoidance, hyperarousal, and dysphoria-provided the best fit. The dysphoria factor combined traditional markers of numbing and hyperarousal. Model superiority was cross-validated in multiple subsamples, including a subset of deployed participants who were exposed to traumatic combat stressors. Moreover, convergent and discriminant validity correlations suggested that intrusions may be relatively specific to PTSD, whereas dysphoria may represent a nonspecific component of many disorders. Results are discussed in the context of hierarchical models of anxiety and depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessing posttraumatic stress disorder with or without reference to a single, worst traumatic event: Examining differences in factor structure.

The authors examined the effects of a methodological manipulation on the Posttraumatic Stress Disorder (PTSD) Checklist’s factor structure: specifically, whether respondents were instructed to reference a single worst traumatic event when rating PTSD symptoms. Nonclinical, trauma-exposed participants were randomly assigned to 1 of 2 PTSD assessment conditions: referencing PTSD symptoms to their worst trauma (trauma-specific group, n = 218) or to their overall trauma history in general (trauma-general group, n = 234). A 3rd group of non-trauma-exposed participants (n = 464) rated PTSD symptoms globally from any stressful event. Using confirmatory factor analysis, the authors show that the 4-factor PTSD model proposed by D. W. King, G. A. Leskin, L. A. King, and F. W. Weathers (1998; separating effortful avoidance and emotional numbing) demonstrated the best model fit for trauma-general and non-trauma-exposed participants. The 4-factor PTSD model proposed by L. J. Simms, D. Watson, and B. N. Doebbeling (2002; emphasizing a general dysphoria factor) demonstrated the best model fit for trauma-specific participants. Measurement invariance testing revealed that non-trauma-exposed participants were different from both trauma-exposed groups on factor structure parameters, but trauma groups were not substantially different from each other. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Longitudinal factor structure of posttraumatic stress symptoms related to intimate partner violence.

Confirmatory factor analysis (CFA) studies have suggested that a model of posttraumatic stress disorder (PTSD) that is characterized by 4 factors is preferable to competing models. However, the composition of these 4 factors has varied across studies, with 1 model splitting avoidance and numbing symptoms (e.g., D. W. King, G. A. Leskin, L. A. King, & F. W. Weathers, 1998) and the other including a dysphoria factor that combines numbing and nonspecific hyperarousal symptoms (L. J. Simms, D. Watson, & B. N. Doebbeling, 2002). Using the PTSD Checklist (F. W. Weathers, B. T. Litz, D. S. Herman, J. A. Huska, & T. M. Keane, 1993) and CFA, the authors compared these models with competing models. A model of PTSD with 4 intercorrelated factors of Intrusions, Avoidance, Dysphoria, and Hyperarousal was found superior among 396 medical patients who screened positive for intimate partner violence (IPV) and 405 women seeking services for IPV. Structural invariance testing indicated that this 4-factor model remains stable across service setting and time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Confirmatory factor analysis of the clinician-administered PTSD Scale: Evidence for the dimensionality of posttraumatic stress disorder.

The Clinician-Administered PTSD Scale (CAPS; Blake et al., 1990) is a structured interview that assesses the 17 key symptoms of posttraumatic stress disorder ( PTSD) as established in the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM–IV; American Psychiatric Association, 1994). CAPS data from 524 treatment-seeking male military veterans were submitted to confirmatory factor analysis to test a series of nested models reflecting alternative representations of PTSD dimensionality: (a) a 4-factor, 1st-order solution; (b) a 2-factor, higher order solution; (c) a single-factor, higher order solution; and (d) a single-factor, 1st-order solution. The model of best fit was the 4-factor, 1st-order solution, containing moderately to highly correlated yet distinct 1st-order factors corresponding to the reexperiencing, effortful avoidance, emotional numbing, and hyperarousal aspects of PTSD. Implications for theory, assessment, and future research are presented in this article. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of posttraumatic stress disorder symptom structure models in Hispanic and White college students.

This study tested measurement invariance between Hispanic (n = 226) and White (n = 278) college students’ responses to a well-validated measure of posttraumatic stress disorder (PTSD) symptoms. Participants completed the PTSD Checklist—Civilian Version (PCL–C; Weathers, Litz, Herman, Juska, & Keane, 1993); however, trauma histories were not assessed, nor were responses to the PCL–C indexed to a specific traumatic event. Eight models were tested using within-groups confirmatory factor analysis (CFA); 3 models (D. King, Leskin, King, & Weathers, 1998; Simms, Watson, & Doebbeling, 2002; Smith, Redd, DuHamel, Vickberg, & Ricketts, 1999) showed good fit for both ethnic groups, although differences in the degree of fit were observed between the 2 ethnic groups. Models that demonstrated good fit were then compared for equivalence using multiple group CFA. Factor loadings were equivalent between groups, but intercepts differed between groups in all 3 models. Mean item score differences between Hispanic and White groups were observed on items assessing emotional upset with reminders (Item B4) and emotional distancing (Item C5). D. King and colleagues (1998) model resulted in the best measurement invariance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparative efficacy, speed, and adverse effects of three PTSD treatments: Exposure therapy, EMDR, and relaxation training.

The authors examined the efficacy, speed, and incidence of symptom worsening for 3 treatments of posttraumatic stress disorder (PTSD): prolonged exposure, relaxation training, or eye movement desensitization and reprocessing (EMDR; N=60). Treatments did not differ in attrition, in the incidence of symptom worsening, or in their effects on numbing and hyperarousal symptoms. Compared with EMDR and relaxation training, exposure therapy (a) produced significantly larger reductions in avoidance and reexperiencing symptoms, (b) tended to be faster at reducing avoidance, and (c) tended to yield a greater proportion of participants who no longer met criteria for PTSD after treatment. EMDR and relaxation did not differ from one another in speed or efficacy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Factor structure of posttraumatic stress disorder as measured by the Impact of Event Scale–Revised: Stability across cultures and time.

This study examined the structure of posttraumatic stress disorder (PTSD) as measured by the Impact of Event Scale–Revised (IES-R; Weiss & Marmar, 1997), tested factorial invariance for samples of 235 Israeli emergency room patients and 306 U.S. undergraduate students, and then evaluated factorial invariance over multiple occasions within the emergency room sample. A four-factor structure representing intrusion, avoidance-numbing, hyperarousal, and sleep emerged as the preferred model. Configural invariance over groups was supported for this model. Likewise, configural invariance over occasions was demonstrated, but metric invariance was not fully supported, with variation in the loadings on the intrusion factor over time seemingly the source of misfit. Interpretations and conclusions center on sleep as a separate factor underlying the structure of the IES-R, the distinction between avoidance and numbing as a function of how the IES-R (vs. the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) operationalizes the numbing feature of PTSD and possible shifts in the meaning of intrusion over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Peritraumatic dissociation and experiential avoidance as prospective predictors of posttraumatic stress symptoms.

Peritraumatic dissociation (PD) and experiential avoidance (EA) have been implicated in the etiology of posttraumatic stress symptomatology (PTSS); however, the function of these two factors in the onset and maintenance of PTSS following a potentially traumatic event is unclear. The temporal relationships between EA, PD, and the four clusters of PTSS proposed by the Simms/Watson dysphoria model (Simms, Watson, & Doebbeling, 2002) were examined in a three-wave prospective investigation of 532 undergraduate women participating in an ongoing longitudinal study at the time of a campus shooting. Path analyses indicated that preshooting EA predicted greater PD, intrusions, and dysphoria symptoms approximately one month postshooting. PD was associated with increased symptomatology across all four clusters 1-month postshooting, while 1-month postshooting EA was associated with higher dysphoria and hyperarousal symptoms eight months postshooting. PD had a significant indirect effect on all four PTSS clusters eight months postshooting via 1-month postshooting symptom reports. The results suggest that both EA and PD show unique influences as risk factors for PTSS following a potentially traumatic event. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Testing the robustness of the dysphoria factor of the Simms et al. (2002) model of posttraumatic stress disorder.

The Simms et al. (2002) four-factor structure of posttraumatic stress disorder (PTSD) has been supported in many factor analytic studies, and the specificity of the dysphoria factor has been questioned because of its strong associations with measures of depression and anxiety. This study addressed this issue by conducting a confirmatory factor analysis while controlling for the symptoms of major depression (MD) and generalized anxiety disorder (GAD). Data from individuals who satisfied Criterion A of the diagnostic criteria for a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM–IV) diagnosis of PTSD (n = 12,467) in the 2004–2005 National Epidemiologic Study on Alcohol and Related Conditions (NESARC) were used in the analysis. The results showed that after controlling for MD and GAD, the factor loadings for dysphoria items were significantly attenuated, although they remained relatively high and statistically significant. The present findings contribute to the debate regarding how PTSD should be conceptualized and assessed in future issues of the DSM. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Heterogeneity in the latent structure of PTSD symptoms among Canadian veterans.

The current study used factor mixture modeling to identify heterogeneity (i.e., latent classes) in 2 well-supported models of posttraumatic stress disorder's (PTSD) factor structure. Data were analyzed from a clinical sample of 405 Canadian veterans evaluated for PTSD. Results were consistent with our hypotheses. Each PTSD factor model was best represented by 2 latent classes of participants, differing with respect to PTSD symptom severity. Furthermore, classes were most strongly distinguished by factor scores related to emotional numbing or dysphoria. For both factor models, class membership was significantly predicted by age and depression diagnosis. Implications of these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Uncontrollability and unpredictability in post-traumatic stress disorder: An animal model.

The disturbances observed in animals subjected to unpredictable and uncontrollable aversive events resemble posttraumatic stress disorder (PTSD) symptoms and thus may constitute an animal model of this disorder. It is argued that the similarity between animals' symptoms and those of trauma victims may reflect common etiological factors. Relevant experiments in which animals exhibit generalized fear and arousal, discrete fear of a CS, analgesia, and avoidance are reviewed with the view that these manifestations may be analogous to the PTSD symptom clusters of persistent arousal, reexperiencing, numbing, and avoidance, respectively. Finally, animal paradigms are suggested to test the validity of the model, and specific hypotheses are derived from the animal literature regarding trauma variables that are predictive of particular PTSD symptom clusters. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

All PTSD symptoms are highly associated with general distress: Ramifications for the dysphoria symptom cluster.

This study used longitudinal data collected from two trauma-exposed samples, survivors of community violence (N = 294) and wildfire evacuees (N = 234), to examine a key claim underlying a proposed reformulation of the symptom structure of posttraumatic stress disorder (PTSD). This theory, which we term the PTSD–dysphoria model, posits that 8 of 17 symptoms of PTSD reflect dysphoria or general psychological distress and might be deemphasized to improve the utility of the PTSD construct (Simms, Watson, & Doebbeling, 2002). For each sample, we analyzed PTSD symptoms and measures of general distress administered at 2 time points. A consistent pattern of findings was observed across assessments for each sample: All 17 PTSD symptoms were highly associated with measures of general distress. Moreover, we found no evidence that dysphoria symptoms were more highly correlated than PTSD-specific symptoms with general distress. Results call into question both the conceptual basis and the clinical utility of differentiating between symptoms that appear to be relatively specific to PTSD and those that seem more broadly characteristic of general psychological distress. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Posttraumatic stress disorder symptoms, physiological reactivity, alcohol problems, and aggression among military veterans.

This study examined the association between posttraumatic stress disorder (PTSD) symptomatology and aggressive behavior among a sample of male Vietnam veterans (N = 1,328). Results indicated that the hyperarousal PTSD symptom cluster evidenced the strongest positive association with aggression at the bivariate level when compared with the other PTSD symptom clusters. When the PTSD symptom clusters were examined together as predictors, hyperarousal symptoms evidenced a significant positive relationship with aggression, and avoidance/numbing symptoms were negatively associated with aggression. Examination of potential mediators indicated that hyperarousal symptoms were directly associated with aggression and indirectly related to aggression via alcohol problems. Reexperiencing symptoms were associated with aggression only indirectly and through their positive association with physiological reactivity and negative association with alcohol problems. Study results highlight the complexity of the relationship between PTSD symptoms and aggression, and suggest possible mechanisms explaining this association. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Posttraumatic symptomatology in children and adolescents after an industrial fire

OBJECTIVE: This investigation evaluated the extent and nature of posttraumatic symptomatology (PTS) in children and adolescents 9 months after an industrial fire at the imperial Foods chicken-processing plant in Hamlet, North Carolina, caused extensive loss of life. METHOD: Using a PTS self-report measure plus self- and teacher reports of comorbid symptoms the authors surveyed 1,019 fourth- to ninth-grade students in the community where the fire occurred. RESULTS: Three factors comprising PTS were identified: reexperiencing, avoidance and hyperarousal. Reexperiencing and avoidance were positively correlated; hyperarousal proved weakly correlated with reexperiencing, perhaps because exposure was largely indirect. Using a T score cutoff of 65 on the reexperiencing factor as indicative of PTS 9.7% of subjects met criteria for PTS; 11.9% met criteria for posttraumatic stress disorder (PTSD) using DSM-III-R PTSD criteria. Degree of exposure was the most powerful predictor of PTS. Race (African-American) and gender (female) posed significant risk factors for PTS. Self-reported internalizing symptoms and teacher-reported externalizing symptoms were positively predicted by intercurrent PTS, and independently of PTS, by degree of exposure. Comorbid symptoms showed interesting interactions with exposure, race, and gender. Lack of self-attributed personal efficacy predicted PTS but did not moderate the effects of race or gender on PTS risk. CONCLUSIONS: This study, which used a population-based sampling strategy, strengthens and extends findings from earlier literature on pediatric PTSD in showing that (1) PTS and comorbid internalizing and externalizing symptoms rise in direct proportion to degree of exposure; (2) gender and race show variable effects on risk for PTS and comorbid symptoms; and (3) comorbid symptoms are positively correlated with PTS and may represent primary outcomes of traumatic exposure in their own right.     

The structure of PTSD among two cohorts of returning soldiers: Before, during, and following deployment to Iraq.

Evidence suggests either a four-factor emotional numbing or dysphoria model likely reflects the underlying structure of posttraumatic stress disorder (PTSD). Questions remain as to which of these structures best represents PTSD, how the structure changes with time, the applicability of models to returning veterans, and the validity of the symptom clusters. The present study addresses these questions among two longitudinal samples of National Guard soldiers assessed prior to, during, and following a combat deployment to Iraq. Findings support a four-factor intercorrelated dysphoria model of PTSD that remains stable across samples and time points. Differential associations were observed among PTSD symptom clusters over time and between symptom clusters and both depression and combat exposure, supporting important distinctions between symptom clusters. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The relationships between posttraumatic stress symptom clusters and marital intimacy among war veterans.

This study examined (a) the relationships between posttraumatic stress disorder (PTSD) symptom clusters and marital intimacy among Israeli war veterans and (b) the role of self-disclosure and verbal violence in mediating the effects of PTSD avoidance and hyperarousal symptoms on marital intimacy. The sample consisted of 219 participants divided into 2 groups: ex-prisoners of war (ex-POWs; N = 125) and a comparison group of veterans who fought in the same war but were not held in captivity (N = 94). Ex-POWs displayed higher levels of PTSD symptoms and verbal violence and lower levels of self-disclosure than did controls. Although ex-POWs and controls did not differ in level of marital intimacy, they did, however, present a different pattern of relationships between PTSD clusters and intimacy. In ex-POWs, self-disclosure mediated the relations between PTSD avoidance and marital intimacy. Verbal aggression was also found via indirect effect of hyperarousal on marital intimacy. The results point to the importance of self-disclosure and verbal violence as interpersonal mechanisms for the relations between posttraumatic symptoms on marital intimacy of ex-POWs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Couple adjustment and posttraumatic stress disorder symptoms in National Guard veterans of the Iraq war.

Relationship adjustment and posttraumatic stress disorder (PTSD) symptoms were assessed across two time points in a sample of 313 married or partnered National Guard soldiers recently returned from combat duty in Iraq. Structural equation modeling using a four-factor model for PTSD found the latent variable dysphoria (reflecting generalized distress including aspects of emotional numbing and arousal) had the strongest independent contribution to predicting relationship adjustment at Time 1 and indirectly predicted poorer relationship adjustment at Time 2. Exploratory analysis of gender differences (n = 33 women; n = 280 men) suggested a different pattern of relations between PTSD factors and relationship adjustment among female soldiers at Time 1, with a trend toward trauma specific avoidance being more highly related to relationship adjustment. Clinical and research implications are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Posttraumatic stress symptoms mediate the relation between childhood sexual abuse and nonsuicidal self-injury.

Prior research consistently has shown a strong relation between childhood abuse and nonsuicidal self-injury (NSSI), yet it is unclear why this relation exists. The authors examined 2 specific posttraumatic stress disorder (PTSD) symptom clusters as potential mechanisms through which childhood abuse may be related to NSSI. Participants were 86 adolescents (78% female, 22% male; 73% Caucasian, 27% other races/ethnicities; mean age = 17.03 years, range = 12-19 years) who completed measures of childhood abuse, Diagnostic and Statistical Manual of Mental Disorders (4th ed.) PTSD symptoms, and NSSI. Analyses revealed a significant relation between childhood sexual abuse in particular and the presence and frequency of NSSI. Moreover, data supported a theoretical model in which PTSD reexperiencing and avoidance/numbing symptoms independently mediate this relation. Future research must test the temporal relation between childhood sexual abuse, PTSD symptoms, and NSSI and identify additional pathways to engagement in NSSI. (PsycINFO Database Record (c) 2010 APA, all rights reserved)