Assessing the factor structure of posttraumatic stress disorder symptoms in war-exposed youths with and without Criterion A2 endorsement

Invariance of the Construct of Posttraumatic Stress Disorder: A Systematic Review

We conducted a systematic review of studies that have evaluated invariance of the construct of posttraumatic stress disorder (PTSD) to summarize their conclusions related to invariance/noninvariance and sources of noninvariance. In November 2017, we searched Pubmed, PSYCINFO, PILOTS Web of Science, CINAHL, Medline, and Psychological and Behavioral Science Collection for abstracts and articles with these inclusionary criteria: peer-reviewed, including DSM-IV or DSM-5 PTSD invariance as a main study aim, use of multigroup confirmatory factor analyses, and use of an independent PTSD instrument or module. In total, 45 articles out of 1,169 initially identified abstracts met inclusion criteria. Research assistants then followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to complete a secondary search and independently extract data. Results indicated that DSM-IV dysphoric arousal and DSM-5 hybrid model factors demonstrated the most stability; sources of instability were some intrusion (distress to trauma cues), dysphoria/numbing (traumatic amnesia, foreshortened future, emotional numbness, detachment), and arousal (hypervigilance) items. The PTSD Checklist and PTSD Reaction Index were most often used to assess PTSD in studies investigating its invariance; however, these measures demonstrated partial conceptual equivalence of PTSD across subgroups. Instead, clinician-administered measures demonstrated more conceptual equivalence across subgroups. Age, gender, cultural/linguistic factors, and sample diversity had the least moderating effect on PTSD's symptom structure. Our review demonstrates the need to examine invariance of the PTSD construct following recommended guidelines for each empirical and clinical trial study to draw meaningful multigroup comparative conclusions.

The relationship between PTSD, depression and negative life events: Ya'an earthquake three years later

PTSD (Posttraumatic Stress Disorder) is a common post-disaster psychological condition which research has shown to have comorbidity with depression. To explore the relationship between PTSD and depression further, a cross-sectional study design was adopted. Three years after the Ya'an earthquake, 4137 adolescents (mean age 15.12) who had personally experienced the earthquake were assessed. The study results showed that PTSD significantly predicted future depression, with the effect being partially mediated by the negative life events after the earthquake. Gender was not found to be a significant moderator between PTSD and depression.

A systematic literature review of PTSD's latent structure in the Diagnostic and Statistical Manual of Mental Disorders: DSM-IV to DSM-5

The factor structure of posttraumatic stress disorder (PTSD) has been widely researched, but consensus regarding the exact number and nature of factors is yet to be reached. The aim of the current study was to systematically review the extant literature on PTSD's latent structure in the Diagnostic and Statistical Manual of Mental Disorders (DSM) in order to identify the best-fitting model. One hundred and twelve research papers published after 1994 using confirmatory factor analysis and DSM-based measures of PTSD were included in the review. In the DSM-IV literature, four-factor models received substantial support, but the five-factor Dysphoric arousal model demonstrated the best fit, regardless of gender, measurement instrument or trauma type. The recently proposed DSM-5 PTSD model was found to be a good representation of PTSD's latent structure, but studies analysing the six- and seven-factor models suggest that the DSM-5 PTSD factor structure may need further alterations.

Dimensional structure and correlates of posttraumatic stress symptoms following suspected acute coronary syndrome

BACKGROUND

Posttraumatic stress disorder (PTSD) is a heterogeneous construct, and some have suggested that PTSD triggered by acute coronary syndrome (ACS) may differ from PTSD due to prototypical traumas.

METHODS

We conducted the first examination of the latent structure of PTSD symptoms after suspected ACS in 399 adults in the REactions to Acute Care and Hospitalization (REACH) study, an observational cohort study of patients recruited from the emergency department during evaluation for ACS. Using confirmatory factor analysis, we compared the 4-factor dysphoria, 4-factor numbing, and 5-factor dysphoric arousal models of PTSD.

RESULTS

Although all models fit well, the dysphoria model was selected as the best-fitting model. Further, there was measurement invariance of the dysphoria model by sex. PTSD dimensions evidenced differential associations with indicators of threat perception during ACS evaluation and adherence to cardioprotective medication.

LIMITATIONS

One limitation of this investigation is the use of self-report measures. In addition, only one-third of the sample was diagnosed with ACS at discharge; the remaining participants received diagnoses such as chest pain without a cardiac diagnosis, another symptom/disease process (e.g., hypertensive chronic kidney disease), or another cardiac disease.

CONCLUSIONS

Findings suggest that suspected ACS-related PTSD symptoms are best-represented by a 4-factor structure distinguishing between specific (e.g., re-experiencing) and non-specific (dysphoria) symptoms of PTSD that has received support in the broader PTSD literature.

An evaluation of the DSM-5 factor structure for posttraumatic stress disorder in survivors of traumatic injury

Confirmatory factor analytic studies of the latent structure of DSM-5 PTSD symptoms using self-report data (Elhai et al., 2012; Miller et al., 2013) have found that the four-factor model implied by the DSM-5 diagnostic criteria provided adequate fit to their data. However, the fit of this model is yet to be assessed using data derived from gold standard structured interview measures. This study evaluated the fit of the DSM-5 four-factor model and an alternative four-factor model in 570 injury survivors six years post-injury using the Clinician Administered PTSD Scale (Blake et al., 1990), updated to include items measuring new DSM-5 symptoms. While both four-factor models fitted the data well, very high correlations between the 'Intrusions' and 'Avoidance' factors in both models and between the 'Negative Alterations in Cognitions and Mood' and 'Arousal and Reactivity' factors in the DSM-5 model and the 'Dysphoria' and 'Hyperarousal' factors in the alternative model were evident, suggesting that a more parsimonious two-factor model combining these pairs of factors may adequately represent the latent structure. Such a two-factor model fitted the data less well according to χ(2) difference testing, but demonstrated broadly equivalent fit using other fit indices. Relationships between the factors of each of the four-factor models and the latent factors of Fear and Anxious-Misery/Distress underlying Internalizing disorders (Krueger, 1999) were also explored, with findings providing further support for the close relationship between the Intrusion and Avoidance factors. However, these findings also suggested that there may be some utility to distinguishing Negative Alterations in Cognition and Mood symptoms from Arousal and Reactivity symptoms, and/or Dysphoria symptoms from Hyperarousal symptoms. Further studies are required to assess the potential discriminant validity of the two four-factor models.

The underlying dimensionality of PTSD in the diagnostic and statistical manual of mental disorders: where are we going?

There has been a substantial body of literature devoted to answering one question: Which latent model of posttraumatic stress disorder (PTSD) best represents PTSD's underlying dimensionality? This research summary will, therefore, focus on the literature pertaining to PTSD's latent structure as represented in the fourth (DSM-IV, 1994) to the fifth (DSM-5, 2013) edition of the DSM. This article will begin by providing a clear rationale as to why this is a pertinent research area, then the body of literature pertaining to the DSM-IV and DSM-IV-TR will be summarised, and this will be followed by a summary of the literature pertaining to the recently published DSM-5. To conclude, there will be a discussion with recommendations for future research directions, namely that researchers must investigate the applicability of the new DSM-5 criteria and the newly created DSM-5 symptom sets to trauma survivors. In addition, researchers must continue to endeavour to identify the "correct" constellations of symptoms within symptom sets to ensure that diagnostic algorithms are appropriate and aid in the development of targeted treatment approaches and interventions. In particular, the newly proposed DSM-5 anhedonia model, externalising behaviours model, and hybrid models must be further investigated. It is also important that researchers follow up on the idea that a more parsimonious latent structure of PTSD may exist.

Examining posttraumatic stress disorder's latent structure between treatment-seeking and non-treatment-seeking Filipinos

BACKGROUND

The discourse of latent structure of posttraumatic stress disorder (PTSD) has been extensive in trauma literature. Although findings have been consistent in rejecting DSM-IV-TR's three-factor model, alternative models are still fervently argued. This study contributes to the discussion by examining and comparing PTSD factor structure of the three most validated models—numbing model (King et al., 1998), dysphoria model (Simms et al., 2002), and dysphoric arousal model (Elhai et al., 2011b)—and determining if these are generalizable across treatment-seeking and non-treatment-seeking Filipinos with exposure to trauma events.

METHODS

Filipino-Tagalog version of Harvard Trauma Questionnaire (HTQ; Mollica et al., 1992) was administered to a sample of 737 treatment-seeking (n=526) and non-treatment-seeking (n=211) Filipinos who experienced and witnessed varied trauma events. Confirmatory factor analysis (CFA) was conducted involving the three models in order to determine the best-fitting model and generalizability across samples.

RESULTS

Results showed that all three models achieved excellent fit, with dysphoric arousal model slightly fitting better than numbing and dysphoria models in both treatment-seeking and non-treatment-seeking samples. Series of invariance testing, however, indicated that although dysphoric arousal model fits significantly better than dysphoria model, it did not significantly differ from numbing model. Results revealed that aside from the factor loadings, the two groups are noninvariant in all parameters. Treatment-seeking sample had larger intercepts, factor variances and covariances and factor means than non-treatment-seeking group.

DISCUSSION

The findings strongly contribute to the literature by showing how the type of groupings (treatment-seeking vs. non-treatment-seeking) moderates PTSD latent structure. It affirms the suggestion of Biehn et al. (2012) to be cautious in concluding the generalizability of PTSD models in the context that type of participants moderates PTSD's factor structure.

Do gender and age moderate the symptom structure of PTSD? Findings from a national clinical sample of children and adolescents

A substantial body of evidence documents that the frequency and intensity of posttraumatic stress disorder (PTSD) symptoms are linked to such demographic variables as female sex (e.g., Kaplow et al., 2005) and age (e.g., Meiser-Stedman et al., 2008). Considerably less is known about relations between biological sex and age with PTSD's latent factor structure. This study systematically examined the roles that sex and age may play as candidate moderators of the full range of factor structure parameters of an empirically supported five-factor PTSD model (Elhai et al., 2011). The sample included 6591 trauma-exposed children and adolescents selected from the National Child Traumatic Stress Network's Core Data Set. Confirmatory factor analysis using invariance testing (Gregorich, 2006) and comparative fit index difference values (Cheung and Rensvold, 2002) reflected a mixed pattern of test item intercepts across age groups. The adolescent subsample produced lower residual error variances, reflecting less measurement error than the child subsample. Sex did not show a robust moderating effect. We conclude by discussing implications for clinical assessment, theory building, and future research.

Post-traumatic stress disorder in DSM-5: estimates of prevalence and criteria comparison versus DSM-IV-TR in a non-clinical sample of earthquake survivors

BACKGROUND

The latest edition of DSM (DSM-5) introduced important revisions to PTSD symptomatological criteria, such as a four-factor model and the inclusion of new symptoms. To date, only a few studies have investigated the impact that the proposed DSM-5 criteria will have on prevalence rates of PTSD.

METHODS

An overall sample of 512 adolescents who survived the L'Aquila 2009 earthquake and were previously investigated for the presence of full and partial PTSD, using DSM-IV-TR criteria, were reassessed according to DSM-5 criteria. All subjects completed the Trauma and Loss Spectrum-Self Report (TALS-SR).

RESULTS

A DSM-5 PTSD diagnosis emerged in 39.8% of subjects, with a significant difference between the two sexes (p<0.001), and an overall 87.1% consistency with DSM-IV-TR. Most of the inconsistent diagnoses that fulfilled DSM-IV-TR criteria but not DSM-5 criteria can be attributed to the subjects not fulfilling the new criterion C (active avoidance). Each DSM-5 symptom was more highly correlated with its corresponding symptom cluster than with other symptom clusters, but two of the new symptoms showed moderate to weak item-cluster correlations. Among DSM-5 PTSD cases: 7 (3.4%) endorsed symptom D3; 151 (74%) D4; 28 (13.7%) both D3 and D4; 75 (36.8%) E2.

LIMITATIONS

The use of a self-report instrument; no information on comorbidity; homogeneity of study sample; lack of assessment on functional impairment; the rates of DSM-IV-TR qualified PTSD in the sample was only 37.5%.

CONCLUSIONS

This study provides an inside look at the empirical performance of the DSM-5 PTSD criteria in a population exposed to a natural disaster, which suggests the need for replication in larger epidemiological samples.

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.

PTSD's latent structure in Malaysian tsunami victims: assessing the newly proposed Dysphoric Arousal model

The underlying latent structure of Posttraumatic Stress Disorder (PTSD) is widely researched. However, despite a plethora of factor analytic studies, no single model has consistently been shown as superior to alternative models. The two most often supported models are the Emotional Numbing and the Dysphoria models. However, a recently proposed five-factor Dysphoric Arousal model has been gathering support over and above existing models. Data for the current study were gathered from Malaysian Tsunami survivors (N=250). Three competing models (Emotional Numbing/Dysphoria/Dysphoric Arousal) were specified and estimated using Confirmatory Factor Analysis (CFA). The Dysphoria model provided superior fit to the data compared to the Emotional Numbing model. However, using chi-square difference tests, the Dysphoric Arousal model showed a superior fit compared to both the Emotional Numbing and Dysphoria models. In conclusion, the current results suggest that the Dysphoric Arousal model better represents PTSD's latent structure and that items measuring sleeping difficulties, irritability/anger and concentration difficulties form a separate, unique PTSD factor. These results are discussed in relation to the role of Hyperarousal in PTSD's on-going symptom maintenance and in relation to the DSM-5.

Psychometric properties of the UCLA PTSD reaction index. part II: investigating factor structure findings in a national clinic-referred youth sample

We examined the underlying factor structure of the UCLA PTSD Reaction Index (PTSD-RI) using data from 6,591 children/adolescents exposed to trauma, presenting for treatment at any of 54 National Child Traumatic Stress Network (NCTSN) centers. Using confirmatory factor analysis, we tested the 3-factor DSM-IV PTSD model, 2 separate 4-factor models (Dysphoria vs. Emotional Numbing) and a recently conceptualized 5-factor Dysphoric Arousal model. We found a slight, but significant advantage for the Dysphoria model over the Emotional Numbing model on the PTSD-RI, with a difference in Bayesian information criterion (BIC) values of 81 points. As with several recent studies of adult trauma victims, we found a slight advantage for the Dysphoric Arousal model over the other models on the PTSD-RI, with BIC differences exceeding 300 points. Retaining the Dysphoric Arousal model, we tested the convergent validity of the PTSD-RI factors against subscales of the Trauma Symptom Checklist for Children. Supporting the convergent validity of the PTSD-RI, in the Dysphoric Arousal model, the dysphoric arousal factor related most strongly to anger, whereas the emotional numbing factor related most strongly to depression, and anxious arousal factor related most strongly to anxiety. Results support the use of the PTSD-RI for evaluating PTSD among youth.

Psychometric properties of the UCLA PTSD reaction index: part I

This article presents psychometric characteristics of the UCLA PTSD Reaction Index for DSM IV (PTSD-RI) derived from a large sample of children and adolescents (N = 6,291) evaluated at National Child Traumatic Stress Network centers. Overall mean total PTSD-RI score for girls was significantly higher as compared with boys. Age-related differences were found in that overall mean total PTSD-RI scores and within sex groups were higher among those aged 7-9 years and 16-18 years. There were no significant differences in mean total PTSD-RI scores across racial/ethnic groups. The PTSD-RI total scale displayed good to excellent internal consistency reliability across age ranges, sex, and racial/ethnic groups (α = .88-.91). Correlations of PTSD-RI scores with PTS subscale scores on the TSCC-A for the entire sample and within sex, age, and ethnic/racial groups provided evidence of convergent validity, although not discriminant validity. In contradistinction to previously reported 4-factor models, an exploratory factor analysis revealed 3 factors that mostly reflected the underlying dimensions of PTSD in DSM IV. PTSD-RI scores were associated with increased odds ratios for functional/behavior problems (odds ratio [OR] = 1-1.80). These findings are striking in light of the wide range of trauma exposures, age, and race/ethnicity among subjects.

The dimensionality of PTSD symptoms and their relationship to health-related quality of life in Chinese earthquake survivors

The current study investigated the latent structure of PTSD symptoms with a sample of 326 Chinese survivors who lost their children during a deadly earthquake. The results of confirmatory factor analysis indicated that a five-factor intercorrelated model comprised of intrusion, avoidance, emotional numbing, dysphoric arousal, and anxiety arousal provided significant better fit than both the four-factor numbing model of King, Leskin, King, and Weathers (1998) and the four-factor dysphoria model of Simms, Watson, and Doebbeling (2002). Further analyses with structural equation modeling showed that the PTSD factors were differentially associated with external measures of psychosocial and physical health-related quality of life. The findings provide further empirical support for the novel five-factor PTSD model, and carry implications for conceptualizing and assessing PTSD for the upcoming DSM-5.

PTSD factor structure differences between veterans with and without a PTSD diagnosis

This study examined differences in posttraumatic stress disorder's (PTSD) factor structure between veterans with and without a PTSD diagnosis. An archival dataset of 378 trauma-exposed Canadian veterans (mostly men) was used. The sample was divided into participants who met DSM-IV criteria for PTSD (n=230) and those who did not (n=148), based on a structured diagnostic interview. Confirmatory factor analysis was conducted to determine which empirically supported four-factor PTSD model best fit the data: (1) King, Leskin, King, and Weathers' (1998) Emotional Numbing model of Reexperiencing, Avoidance, Emotional Numbing and Hyperarousal factors, or (2) Simms, Watson, and Doebbeling's (2002) Dysphoria model of Reexperiencing, Avoidance, Dysphoria, and Hyperarousal factors. Results indicated that both models fit slightly better in the No-PTSD group. A series of measurement invariance tests demonstrated that the two groups varied on all parameters with the exception of factor loadings. The PTSD-group had larger intercepts, factor means, and residual error variance, suggesting that these participants had greater PTSD severity but more measurement error associated with their PTSD ratings. This study contributes to our understanding of how a PTSD diagnosis impacts the structure of PTSD symptoms at the latent level.

Assessing a five factor model of PTSD: is dysphoric arousal a unique PTSD construct showing differential relationships with anxiety and depression?

Posttraumatic stress disorder's (PTSD) latent structure has been widely debated. To date, two four-factor models (Numbing and Dysphoria) have received the majority of factor analytic support. Recently, Elhai et al. (2011) proposed and supported a revised (five-factor) Dysphoric Arousal model. Data were gathered from two separate samples; War veterans and Primary Care medical patients. The three models were compared and the resultant factors of the Dysphoric Arousal model were validated against external constructs of depression and anxiety. The Dysphoric Arousal model provided significantly better fit than the Numbing and Dysphoria models across both samples. When differentiating between factors, the current results support the idea that Dysphoric Arousal can be differentiated from Anxious Arousal but not from Emotional Numbing when correlated with depression. In conclusion, the Dysphoria model may be a more parsimonious representation of PTSD's latent structure in these trauma populations despite superior fit of the Dysphoric Arousal model.

Posttraumatic stress disorder in DSM-5: estimates of prevalence and symptom structure in a nonclinical sample of college students

We empirically investigated recent proposed changes to the posttraumatic stress disorder (PTSD) diagnosis for DSM-5 using a non-clinical sample. A web survey was administered to 585 college students using the Stressful Life Events Screening Questionnaire to assess for trauma exposure but with additions for the proposed traumatic stressor changes in DSM-5 PTSD. For the 216 subjects endorsing previous trauma exposure and nominating a worst traumatic event, we administered the original PTSD Symptom Scale based on DSM-IV PTSD symptom criteria and an adapted version for DSM-5 symptoms, and the Center for Epidemiological Studies-Depression Scale. While 67% of participants endorsed at least one traumatic event based on DSM-IV PTSD's trauma classification, 59% of participants would meet DSM-5 PTSD's proposed trauma classification. Estimates of current PTSD prevalence were .4-1.8% points higher for the DSM-5 (vs. the DSM-IV) diagnostic algorithm. The DSM-5 symptom set fit the data very well based on confirmatory factor analysis, and neither symptom set's factors were more correlated with depression.

Testing the dimensionality of posttraumatic stress responses in young Chinese adult earthquake survivors: further evidence for "dysphoric arousal" as a unique PTSD construct

BACKGROUND

This study investigated an alternative five-factor diagnostic model for posttraumatic stress disorder (PTSD) symptoms, and tested external convergent and discriminant validity of the model in a young Chinese sample of earthquake survivors.

METHODS

A total of 938 participants (456 women, 482 men) aged 15-20 years were recruited from a vocational school originally located in Beichuan County Town which was almost completely destroyed by the "Wenchuan Earthquake." The participants were administrated with the PTSD Checklist and the Hopkins Symptoms Checklist-25 12 months after the earthquake.

RESULTS

The results of confirmatory factor analysis showed that the five-factor intercorrelated model (intrusion, avoidance, numbing, dysphoric arousal, and anxious arousal) fit the data significantly better than the four-factor numbing model proposed by King et al. (1998: Psychol Assess 10:90-96) and the four-factor dysphoria model proposed by Simms et al. (2002: J Abnorm Psychol 111:637-647). Further analyses indicated that four out of five PTSD factors yielded significantly different correlations with external measures of anxiety versus depression.

CONCLUSIONS

The findings provide further empirical evidence in favor of the five-factor diagnostic model of PTSD, and carry implications for the upcoming DSM-5.

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.

Comparing alternative factor models of PTSD symptoms across earthquake victims and violent riot witnesses in China: evidence for a five-factor model proposed by Elhai et al. (2011)

The present study investigated the factor structure of posttraumatic stress disorder (PTSD) symptoms measured by the PTSD Checklist (PCL) in two large samples exposed to different traumatic events (an earthquake and a violent riot) from China. Despite the samples' difference in type of trauma, demographics, symptom severity, and elapsed time since trauma exposure, the results of a series of confirmatory factor analyses indicate that a five-factor intercorrelated model (intrusion, avoidance, numbing, dysphoric arousal, and anxious arousal) fit the data significantly better than the other alternative models including: the three-factor DSM-IV model, the four-factor numbing model (King et al., 1998), and the four-factor dysphoria model (Simms et al., 2002) in both samples. Implications and limitations regarding the results are discussed.

The factor structure of posttraumatic stress disorder: a literature update, critique of methodology, and agenda for future research

We present an update of recent literature (since 2007) exploring the factor structure of posttraumatic stress disorder (PTSD) symptom measures. Research supporting a four-factor emotional numbing model and a four-factor dysphoria model is presented, with these models fitting better than all other models examined. Variables accounting for factor structure differences are reviewed, including PTSD query instructions, type of PTSD measure, extent of trauma exposure, ethnicity, and timing of administration. Methodological and statistical limitations with recent studies are presented. Finally, a research agenda and recommendations are offered to push this research area forward, including suggestions to validate PTSD’s factors against external measures of psychopathology, test moderators of factor structure, and examine heterogeneity of symptom presentations based on factor structure examination.

Evidence for a unique PTSD construct represented by PTSD's D1-D3 symptoms

Two models of posttraumatic stress disorder (PTSD) have received the most empirical support in confirmatory factor analytic studies: King, Leskin, King, and Weathers' (1998) Emotional Numbing model of reexperiencing, avoidance, emotional numbing and hyperarousal; and Simms, Watson, and Doebbeling's (2002) Dysphoria model of reexperiencing, avoidance, dysphoria and hyperarousal. These models only differ in placement of three PTSD symptoms: sleep problems (D1), irritability (D2), and concentration problems (D3). In the present study, we recruited 252 women victims of domestic violence and tested whether there is empirical support to separate these three PTSD symptoms into a fifth factor, while retaining the Emotional Numbing and Dysphoria models' remaining four factors. Confirmatory factor analytic findings demonstrated that separating the three symptoms into a separate factor significantly enhanced model fit for the Emotional Numbing and Dysphoria models. These three symptoms may represent a unique latent construct. Implications are discussed.