Dimensionality of posttraumatic stress symptoms: a confirmatory factor analysis of DSM-IV symptom clusters and other symptom models

Recent exploratory [Taylor, S., Kuch, K., Koch, W. J., Crockett, D. J., & Passey, G. (1998). The structure of posttraumatic stress symptoms. Journal of Abnormal Psychology, 107, 154-160.] and confirmatory [Buckley, T. C., Blanchard, E. B., & Hickling, E. J. (1998). A confirmatory factor analysis of posttraumatic stress symptoms. Behaviour Research and Therapy, 36, 1091-1099; King, D. W., Leskin, G. A., King, L. A., & Weathers, F. W. (1998). Confirmatory factor analysis of the clinician-administered PTSD scale: evidence for the dimensionality of posttraumatic stress disorder. Psychological Assessment, 10, 90-96.] factor analytic investigations suggest that the three symptom clusters of posttraumatic stress disorder (PTSD) as defined in the Diagnostic and Statistical Manual [4th ed.; DSM-IV; American Psychiatric Association (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington, DC: Author.] may not provide the best conceptualization of symptom dimensionality. However, the alternative models have not been in agreement, nor have they been compared against each other or models based on the DSM-IV. The purpose of the present investigation was to test a series of dimensional models suggested by these recent factor analytic investigations and the DSM-IV. Using data collected with the PTSD Checklist--Civilian Version [Weathers, F. W., Litz, B. T., Huska, J. A., & Keane, T. M. (1994). PCL-C for DSM-IV. Boston: National Center for PTSD--Behavioral Science Division.] from 349 referrals to a primary care medical clinic, we used confirmatory factor analysis to evaluate a: (1) hierarchical four-factor model, (2) four-factor intercorrelated model, (3) hierarchical three-factor model, (4) three-factor intercorrelated model, and (5) hierarchical two-factor model. The hierarchical four-factor model (comprising four first-order factors corresponding to reexperiencing, avoidance, numbing, and hyperarousal all subsumed by a higher-order general factor) provided the best overall fit to the data; although, all models met some standards specified for good model fit. More research is needed to establish the dimensional nature of PTSD symptoms and to assess whether identified dimensions differ as a function of the trauma experience. Implications for assessment, diagnosis, and treatment are also discussed.     

Confirmatory Factor Analysis of the Posttraumatic Stress Disorder Checklist

Several studies have employed confirmatory factor analysis (CFA) to examine the latent structure of the Posttraumatic Stress Disorder (PTSD) Checklist (PCL; Weathers, Litz, Herman, Huska, & Keane, 1993), a measure that assesses PTSD symptomatology. Findings have failed to support the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text revision [DSM–IV–TR]; American Psychiatric Association, 2000) PTSD model, consisting of reexperiencing, avoidance/numbing, and arousal factors, and no consensus has emerged regarding the best fitting alternative model. Additionally, most studies have utilized homogeneous trauma samples. This study used CFA to examine the PCL factor structure in a sample with exposure to various traumatic events. Superior fit was demonstrated by a model specifying reexperiencing, avoidance, dysphoria, and arousal factors.     

Construct validity of the posttraumatic stress disorder checklist in cancer survivors: analyses based on two samples

The measurement of posttraumatic stress disorder (PTSD) is critically important for the identification and treatment of this disorder. The PTSD Checklist (PCL; F. W. Weathers and J. Ford, 1996) is a self-report measure that is increasingly used. In this study, the authors investigated the factorial validity of the PCL with data from 236 cancer survivors who received a bone marrow or stem cell transplantation. The authors examined the fit of these data with the clinical model of 3 symptom clusters for PTSD, as proposed in the Diagnostic and Statistical Manual of Mental Disorders, and alternative models tested in prior research. By using confirmatory factor analysis the authors found that a 4-first-order-factor model of PTSD provided the best fit. The relations of PTSD symptoms with sociodemographic and medical variables were also explored.     

Change in posttraumatic stress disorder symptoms: do clinicians and patients agree?

This study assessed the longitudinal association between clinician and patient ratings of posttraumatic stress disorder (PTSD) symptoms over the course of 2 different randomized clinical trials of veterans with chronic PTSD. One trial, the Department of Veterans Affairs Cooperative Study 420 (CSP 420; N = 360) compared trauma-focused and present-centered group therapies, and the 2nd trial compared cognitive processing theory and a waitlist control condition (N = 60). Linear mixed effects modeling revealed significant associations between clinician ratings (Clinician-Administered PTSD Scale; CAPS; D. D. Blake et al., 1990) and patient ratings (Posttraumatic Stress Disorder Checklist; PCL; F. W. Weathers, B. T. Litz, J. A. Herman, J. A. Huska, & T. M. Keane, 1993) in total and symptom clusters of PTSD. Contrary to hypothesis, the amount of change on the CAPS ranged from .75 to .82 standard deviations for every 1 standard deviation change on the PCL. The CAPS and PCL were more closely associated in the trauma-focused vs. present-centered treatment condition in CSP 420, and especially regarding hyperarousal symptoms. When comparing categorization of clinically significant change on the CAPS and PCL, the authors found no differences in the percentages of agreement between clinicians and patients in improvement and exacerbation. The value of multimodal assessment of PTSD treatment outcomes is discussed.     

Comparing posttraumatic stress disorder's symptom structure between deployed and nondeployed veterans

We tested two empirically validated 4-factor models of posttraumatic stress disorder (PTSD) symptoms using the PTSD Checklist: King, Leskin, King, and Weathers' (1998) model including reexperiencing, avoidance, emotional numbing, and hyperarousal factors, and Simms, Watson, and Doebbeling's (2002) model including reexperiencing, avoidance, dysphoria, and hyperarousal. Our aim was to determine which fit better in two groups of military veterans: peacekeepers previously deployed to a war zone (deployed group) and those trained for peacekeeping operations who were not deployed (nondeployed group). We compared the groups using multigroup confirmatory factor analysis. Adequate model fit was demonstrated among the nondeployed group, with no significant difference between King et al.'s (1998) model (separating avoidance and numbing) and Simms et al.'s (2002) similar model involving a dysphoria factor. A better fitting factor structure consistent with Simms et al.'s (2002) model was found in the deployed group. Comprehensive measurement invariance testing demonstrated significant differences between the deployed and nondeployed groups on all structural parameters, except observed variable intercepts (thus indicating similarities only in PTSD item severity). These findings add to researchers' understanding of PTSD's factor structure, given the revision of PTSD that will appear in the forthcoming 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 2010)--namely, that the factor structure may be quite different between groups with and without exposure to major traumatic events.     

Symptoms of Post-Traumatic Stress Disorder in Bereaved Children and Adolescents: Factor Structure and Correlates

This study investigated the factor structure and correlates of posttraumatic stress-disorder (PTSD) symptoms among children and adolescents confronted with the death of a loved one. Three hundred thirty-two bereaved children and adolescents (aged 8–18; 56.9 % girls) who all received some form of psychosocial support after their loss, completed self-report measures of PTSD, together with measures tapping demographic and loss-related variables, depression, prolonged grief, and functional impairment. Parent-rated indices of impairment were also collected. We first evaluated the fit of six alternative models of the factor structure of PTSD symptoms, using confirmatory factor analyses. Outcomes showed that the 4-factor numbing model from King et al. (Psychological Assessment 10, 90–96, 1998), with distinct factors of reexperiencing, avoidance, emotional numbing, and hyperarousal fit the data best. Of all participants, 51.5 % met DSM-IV criteria for PTSD. PTSD-status and scores on the PTSD factors varied as a function of age and gender, but were unrelated to other demographic and loss-related variables. PTSD-status and scores on the PTSD factors were significantly associated symptom-levels of depression, prolonged grief, and functional impairment. Findings complement prior evidence that the DSM-IV model of the factor structure of PTSD symptoms may not represent the best conceptualization of these symptoms and highlight the importance of addressing PTSD symptoms in children and adolescents seeking help after bereavement.     

Latent structure of the Post-Traumatic Stress Disorder (PTSD) Checklist for DSM-5 (PCL-5) in South African mortuary workers

This study applied confirmatory factor analysis (CFA) to determine the dimensionality of PTSD symptoms as measured by the Post-Traumatic Stress Disorder Checklist for DSM-5 (PCL-5, Weathers et al., 2013). Participants were 150 trauma-exposed mortuary workers. Six alternative factor solutions resulted from the CFA; including Dysphoria model (four-factor), Dysphoric Arousal model (five-factor), Anhedonia model (six-factor), Externalising model (six-factor), and Hybrid model (seven-factor). Compared to the other models, the five-factor Dysphoric Arousal model had superior fit to the data. Overall, the current results provide evidence for the factorial validity and reliability of scores for the PCL-5 for research use in the South African context.     

Posttraumatic Stress Disorder Symptom Structure in Chinese Adolescents Exposed to a Deadly Earthquake

This present study examined the structure of posttraumatic stress disorder (PTSD) symptoms in a large sample of Chinese adolescents exposed to a deadly earthquake. A total of 2,800 middle school students aged 12 to 18 years participated in the study 6 months after the “Wenchuan Earthquake”. Results of confirmatory factor analysis indicated that a five-factor intercorrelated model composed of intrusion, avoidance, numbing, dysphoric arousal, and anxious arousal, fit data significantly better than both the four-factor numbing model King et al. (Psychological Assessment 10:90–96, 1998) and the four-factor dysphoria model Simms et al. (Journal of Abnormal Psychology 111:637–647, 2002). Further examination of the external convergent and discriminant validity revealed that except for the dysphoric arousal factor, the remaining four PTSD factors yielded significantly different correlations with external measures of anxiety vs. depression. The findings add to the limited literature on the factor structure of PTSD in youths and on the five-factor PTSD model. In addition, they provide more detail into the latent psychopathological processes of PTSD, and inform the forthcoming DSM-5.     

The Role of PTSD and Length of Shelter Stay in Battered Women's Severity of Reabuse after Leaving Shelter

Intimate partner violence (IPV) is associated with significant morbidity, including high rates of reabuse even after women have taken steps to achieve safety. This study evaluated the roles of posttraumatic stress disorder (PTSD) symptom severity and length of shelter stay in the severity of reabuse in 103 IPV victims over a six-month period after leaving a battered women's shelter. Results suggest that the length of shelter stay is inversely related to reabuse severity after leaving shelter. Additionally, more severe PTSD symptoms on shelter exit were associated with greater reabuse severity after leaving shelter. Furthermore, additional study findings support prior research suggesting that the emotional numbing symptoms of PTSD are a significant risk factor for reabuse among IPV victims after leaving shelter.     

Psychometric analyses of the Clinician-Administered PTSD Scale (CAPS)--Bosnian translation

Methods for assessing psychological distress in culturally diverse populations are not firmly established. This study was designed to examine the psychometric properties of the Bosnian translation of the Clinician-Administered PTSD Scale (CAPS; D. D. Blake, F. W. Weathers, L. M. Nagy, D. Kaloupek, G. Klauminzer, D. Charney, et al., 1995) in a Bosnian refugee sample. The authors interviewed 115 help-seeking Bosnian refugees with the CAPS-Bosnian translation to examine its internal consistency and convergent validity, and to provide an assessment of its factor structure. This study demonstrated optimal fit with a 2-factor model of posttraumatic stress disorder (PTSD); the authors also found high reliability with a coefficient alpha of 0.92 and strong convergent validity with instruments measuring depression, anxiety, and levels of psychosocial functioning. Future directions for the assessment of PTSD in cross-cultural populations are discussed.     

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.     

Childhood Maltreatment and PTSD: Spiritual Well-Being and Intimate Partner Violence as Mediators

Childhood maltreatment places individuals, including African American women who are undereducated and economically disadvantaged, at risk for developing posttraumatic stress disorder (PTSD) symptoms. Participants were 192 African American women with a history in the prior year of both a suicide attempt and intimate partner violence (IPV) exposure. They were recruited from a public hospital that provides medical and mental health treatment to mostly low-income patients. A simple mediator model was used to examine if (a) existential well-being (sense of purpose) or religious well-being (relationship with God) mediated the link between childhood maltreatment and adult PTSD symptoms. Sequential multiple mediator models determined if physical and nonphysical IPV enhanced our understanding of the mediational association among the aforementioned variables. Findings suggest that existential well-being mediated the association between childhood maltreatment and adult PTSD symptoms in a simple mediator model, and existential well-being and recent nonphysical IPV served as sequential multiple mediators of this link. However, religious well-being and physical IPV were not significant mediators. Findings underscore the importance of enhancing existential well-being in the treatment of suicidal African American women with a history of childhood maltreatment and IPV.     

A meta-analytic investigation of the structure of posttraumatic stress disorder symptoms

Converging lines of evidence have called into question the validity of conceptualizations of posttraumatic stress disorder (PTSD) based on the Diagnostic and Statistical Manual of Mental Disorders (DSM; American Psychiatric Association, 2000) and suggested alternative structural models of PTSD symptomatology. We conducted a meta-analysis of 40 PTSD studies (N = 14,827 participants across studies) that used a DSM-based measure to assess PTSD severity. We aggregated correlation matrices across studies and then applied confirmatory factor analysis to the aggregated matrices to test the fit of competing models of PTSD symptomatology that have gained support in the literature. Results indicated that both prominent 4-factor models of PTSD symptomatology yielded good model fit across subsamples of studies; however, the model comprising Intrusions, Avoidance, Hyperarousal, and Dysphoria factors appeared to fit better across studies. Results also indicated that the best fitting models were not moderated by measure or sample type. Results are discussed in the context of structural models of PTSD and implications for the diagnostic nosology.     

The structure of DSM-5 posttraumatic stress disorder symptoms in war veterans

Background and Objectives: The present research examined the underlying factor structure of posttraumatic stress disorder (PTSD) as conceptualized in the recently published fifth edition of the Diagnostic and statistical manual of mental disorders (DSM-5). Design: Participants were 258 trauma-exposed Iraq/Afghanistan war veterans. Methods: A self-report measure of PTSD symptoms was administered to all participants and confirmatory factor analysis (CFA) was used to compare several different models of PTSD. Results: CFA revealed that the best-fitting model was a six-factor model in which symptoms loaded onto the factors of intrusion, avoidance, negative affect, anhedonia, dysphoric arousal, and anxious arousal. Conclusions: These findings have important implications for ongoing conceptualization of PTSD and suggest that additional modifications to the diagnostic criteria for PTSD may still be warranted to more accurately reflect the underlying structure of PTSD symptoms.     

Relationships between Past Trauma Exposures and PTSD among Survivors of Intimate Partner Violence

This study examined child abuse and community violence exposure as potential risk factors in the development of posttraumatic stress disorder (PTSD) symptoms following exposure to intimate partner violence (IPV). In a community sample of 51 primarily low-income women who had experienced IPV, childhood exposure to child abuse made a unique contribution to PTSD symptom severity from subsequent IPV. Community violence also accounted for variance in PTSD symptom severity, but in the opposite direction, with individuals exposed to community violence reporting lower levels of PTSD symptoms from IPV. These findings suggest the need for further research to identify which factors related to community violence exposure might inoculate individuals against the development of PTSD following IPV exposure.     

地震后青少年创伤后应激障碍的潜在结构分析

为考察地震后青少年创伤后应激障碍（PTSD）的潜在症状结构,本研究采用儿童创伤后应激障碍症状量表和儿童抑郁量表,对汶川地震一年后的746名中学生进行调查。利用验证性因素分析对竞争模型进行比较,结果发现包括侵入性、回避性、麻木性、精神痛苦性唤起和焦虑性唤起等5个症状的PTSD精神痛苦性唤起模型显著优于DSM-IV的PTSD模型、4维情感麻木模型和4维精神痛苦模型。效度分析的结果发现,PTSD精神痛苦性唤起模型具有良好的外部区分效度。所有结果均表明PTSD精神痛苦性唤起模型在汶川地震后青少年群体中具有良好的适用性,可以作为判定震后青少年PTSD症状的有效标准。     

Examining impelling and disinhibiting factors for intimate partner violence in veterans

We examined correlates of intimate partner violence (IPV) in a military Veteran sample (N = 129) using Finkel's (2007) framework for understanding the interactions between impelling and disinhibiting risk factors. Correlates investigated included head contact events (HCEs), posttraumatic stress disorder (PTSD) symptoms, and antisocial features. Results indicated that antisocial features were significantly associated with IPV at the bivariate level. PTSD symptoms also were associated with IPV, but this association was marginally significant. Tests of moderation provided support for the expectation that HCEs would potentiate associations between antisocial features and IPV. HCEs also moderated the association between PTSD symptoms and IPV. However, contrary to expectations, the opposite pattern emerged such that PTSD symptoms were associated with a higher rate of IPV for those without a history of HCEs. Study findings have potentially important implications for furthering our understanding of the complex etiology of IPV in this population.     

The tripartite model and dimensions of anxiety and depression: an examination of structure in a large school sample

This study was designed to build on recent findings that (a) factors of the tripartite model in adults are not uniformly related to all anxiety disorder dimensions as recent research has suggested (T. A. Brown, B. F. Chorpita, & D. H. Barlow, 1998; S. Mineka, D. W. Watson, & L. A. Clark, 1998), and (b) the tripartite model of emotion appears to have increasing support and utility in child samples (e.g., C. J. Lonigan, E. S. Hooe, C. F. David, & J. A. Kistner, 1999). The structural relations were evaluated among tripartite factors and dimensions representing selected anxiety disorders and depression in a large multiethnic school sample of children and adolescents. General aspects of the tripartite model were supported. For example, Negative Affect was positively related with all anxiety and depression scales, and Positive Affect was negatively correlated with the depression scale. Consistent with previous observations in adult samples, Physiological Hyperarousal was positively related with Panic only, and was not significantly positively correlated with other anxiety syndromes. The structure of the best fitting model appeared robust across different grade levels and gender. In follow-up analyses, several interactions of grade level with structural parameters emerged, such that the relation of some of the tripartite factors with anxiety and depression were noted to increase or decrease across grade level.     

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.     

Associations between dimensions of anxiety sensitivity and PTSD symptom clusters in active-duty police officers

Prior studies have shown that anxiety sensitivity (AS) plays an important role in posttraumatic stress disorder (PTSD) symptom severity. The purpose of this study was to evaluate associations between empirically supported PTSD symptom clusters (i.e. reexperiencing, avoidance, numbing, hyperarousal) and AS dimensions (i.e. psychological concerns, social concerns, somatic concerns). Participants were 138 active-duty police officers (70.7% female; mean age = 38.9 years; mean time policing = 173.8 months) who, as a part of a larger study, completed measures of trauma exposure, PTSD symptoms, AS, and depressive symptoms. All participants reported experiencing at least one event that they perceived as traumatic, and 44 (31.9%) screened positive for PTSD. Officers with probable PTSD scored significantly higher on AS total as well as the somatic and psychological concerns dimensional scores than did those without PTSD. As well, a higher percentage of officers with probable PTSD scored positively on the AS-derived Brief Screen for Panic Disorder (Apfeldorf et al., 1994) compared with those without PTSD. A series of regression analyses revealed that depressive symptoms, number of reported traumas, and AS somatic concerns were significant predictors of PTSD total symptom severity as well as severity of reexperiencing. Avoidance was predicted by depressive symptoms and AS somatic concerns. Only depressive symptoms were significantly predictive of numbing and hyperarousal cluster scores. These findings contribute to understanding the nature of association between AS and PTSD symptom clusters. Implications for the treatment of individuals having PTSD with and without panic-related symptomatology are discussed.