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

Is factor analysis useful for revising diagnostic criteria for PTSD? A systematic review of five issues ten years after DSM-5

BACKGROUND

Based on factor analysis research, DSM-5 revised the diagnostic criteria for posttraumatic stress disorder (PTSD) by increasing symptom clusters from three to four.

AIMS

To question whether that is an appropriate use of factor analysis.

METHODS

Reviewed the literature on five issues of factor analysis relevant to diagnostic criteria: (1) discovery of factors identical to symptom clusters, (2) consensus about the number of factors in best-fitting models, (3) configural variance between subpopulations to explain inconsistent model results, (4) methods to externally validate factors after discovery, and (5) treatment response of symptom clusters to externally validate factors. Two hundred four articles using DSM-IV or DSM-5 symptoms were included.

RESULTS

Two of four DSM-5 clusters were discovered with exploratory factor analysis. Support for a best-fitting model was inconsistent. Models with the highest number of factors were the best mathematical fit 87% of the time. Subpopulations did not reveal a pattern of configural variance to explain inconsistent findings. External validation of factors relied entirely on questionnaires. A review of 143 randomized controlled trials did not reveal differential treatment response of any symptom cluster.

CONCLUSION

Findings did not support the usefulness of factor analysis because the findings are too disparate to be helpful.

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.

Relations between PTSD and depression symptom clusters in samples differentiated by PTSD diagnostic status

Co-occurring posttraumatic stress disorder (PTSD) and depression following traumatic experiences are cumulatively associated with functional impairment. To examine mechanisms for the PTSD-depression comorbidity, we investigated their cluster-level associations. Using data obtained from Amazon's Mechanical Turk platform, 368 trauma-exposed participants were split into two subsamples: those with (n = 163) and without (n = 185) probable PTSD. In both subsamples, confirmatory factor analyses indicated an optimal seven-factor PTSD Hybrid Model. Results of Wald tests of parameter constraints indicated that, in both subsamples, PTSD's dysphoric arousal cluster strongly related to somatic depression compared to all/most other PTSD Hybrid Model clusters. Additionally, in both subsamples, PTSD's negative affect, externalizing behaviors, and anhedonia clusters each strongly related to non-somatic depression compared to PTSD's anxious arousal cluster. Our results indicated that PTSD's dysphoric arousal symptoms mainly accounted for PTSD's shared variance with somatic depression, while the negative alterations in cognitions and mood (NACM)/dysphoria and arousal symptoms (primarily externalizing behaviours) mainly accounted for PTSD's shared variance with non-somatic depression. Our findings have implications for the discussion on PTSD's specific/non-specific clusters tied to diagnostic modifications, for understanding mechanisms underlying PTSD-depression comorbidity, and for the use of transdiagnostic and multi-component treatment protocols for PTSD-depression symptoms.

Latent factor structure of PTSD symptoms in veterans with a history of mild traumatic brain injury and close-range blast exposure

OBJECTIVE

Confirmatory factor analysis (CFA) has previously been employed to examine the latent factor structure of posttraumatic stress disorder (PTSD) symptoms with mixed results. A limited number of studies examined PTSD factor structure among veterans of recent military conflicts. This study examined the relationship between PTSD factor structure and the hallmark conditions of these conflicts, mild traumatic brain injury (mTBI) and close-range blast exposure (CBE).

METHOD

The fit of previously proposed PTSD factor models was compared in a cohort of 387 combat-exposed veterans, with stratified analyses comparing factor structure models between those with a history of military-related mTBI and CBE (n = 106) and those without either of these antecedents (n = 151). CFAs were conducted using criteria from the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; American Psychiatric Association, 1994).

RESULTS

The 4-factor emotional numbing (EN) model yielded the best fit when using a clinician-administered assessment of PTSD symptoms regardless of mTBI/CBE exposure status. However, when using a self-report measure of PTSD symptom severity, the EN model yielded best fit for those with mTBI/CBE exposure history while the 5-factor dysphoric arousal (DA) model was preferable among combat-exposed veterans with no history of mTBI/CBE exposure.

CONCLUSIONS

Factors including mTBI and blast exposure and type of assessment tools must be considered when determining preferable PTSD latent factor structure models. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

PTSD's factor structure and measurement invariance across subgroups with differing count of trauma types

To investigate the effect of the count of traumatizing event (TE) types on post-trauma mental health, several studies have compared posttraumatic stress disorder (PTSD) severity between individuals experiencing one versus multiple TE types. However, the validity of these studies depends on the establishment of measurement invariance of the construct(s) of interest. The current study examined the stability of the most optimal PTSD Model symptom cluster constructs (assessed by the PTSD Checklist for DSM-5 [PCL-5]) across subgroups experiencing one versus multiple TE types. The sample included university students (n = 556) endorsing at least one TE (Stressful Life Events Screening Questionnaire). Using data from the entire sample, results suggest that the PCL-5-assessed Hybrid Model provided a significantly better fit compared to other models. Results also indicated invariance of factor loadings (metric), and intercepts (scalar) for the PCL-5-assessed Hybrid Model factors across subgroups endorsing one (n = 191) versus multiple TE types (n = 365). Our findings thus support the stability, applicability, and meaningful comparison of the PCL-assessed Hybrid Model factor structure (including subscale severity scores) across subgroups experiencing one versus multiple TE types.

The interpersonal theory of suicide: A systematic review and meta-analysis of a decade of cross-national research

Over the past decade, the interpersonal theory of suicide has contributed to substantial advances in the scientific and clinical understanding of suicide and related conditions. The interpersonal theory of suicide posits that suicidal desire emerges when individuals experience intractable feelings of perceived burdensomeness and thwarted belongingness and near-lethal or lethal suicidal behavior occurs in the presence of suicidal desire and capability for suicide. A growing number of studies have tested these posited pathways in various samples; however, these findings have yet to be evaluated meta-analytically. This paper aimed to (a) conduct a systematic review of the unpublished and published, peer-reviewed literature examining the relationship between interpersonal theory constructs and suicidal thoughts and behaviors, (b) conduct meta-analyses testing the interpersonal theory hypotheses, and (c) evaluate the influence of various moderators on these relationships. Four electronic bibliographic databases were searched through the end of March, 2016: PubMed, Medline, PsycINFO, and Web of Science. Hypothesis-driven meta-analyses using random effects models were conducted using 122 distinct unpublished and published samples. Findings supported the interpersonal theory: the interaction between thwarted belongingness and perceived burdensomeness was significantly associated with suicidal ideation; and the interaction between thwarted belongingness, perceived burdensomeness, and capability for suicide was significantly related to a greater number of prior suicide attempts. However, effect sizes for these interactions were modest. Alternative configurations of theory variables were similarly useful for predicting suicide risk as theory-consistent pathways. We conclude with limitations and recommendations for the interpersonal theory as a framework for understanding the suicidal spectrum. (PsycINFO Database Record

Relations between anger and DSM-5 posttraumatic stress disorder symptoms

The present study investigated the relationship between posttraumatic stress disorder (PTSD) and anger. Anger co-occurring with PTSD is found to have a severe effect across a wide range of traumatic experiences, making this an important relationship to examine. The present study utilized data regarding dimensions of PTSD symptoms and anger collected from a non-clinical sample of 247 trauma-exposed participants. Confirmatory factor analysis (CFA) was used to determine the underlying factor structure of both PTSD and anger by examining anger in the context of three models of PTSD. Results indicate that a five-factor representation of PTSD and one-factor representation of anger fit the data best. Additionally, anger demonstrated a strong relationship with the dysphoric arousal and negative alterations in cognitions and mood (NACM) factors; and dysphoric arousal was differentially related to anger. Clinical implications include potential need to reevaluate PTSD's diagnostic symptom structure and highlight the potential need to target and treat comorbid anger in individuals with PTSD. In regard to research, these results support the heterogeneity of PTSD.

Can the dissociative PTSD subtype be identified across two distinct trauma samples meeting caseness for PTSD?

INTRODUCTION

For over a century, the occurrence of dissociative symptoms in connection to traumatic exposure has been acknowledged in the scientific literature. Recently, the importance of dissociation has also been recognized in the long-term traumatic response within the DSM-5 nomenclature. Several studies have confirmed the existence of the dissociative posttraumatic stress disorder (PTSD) subtype. However, there is a lack of studies investigating latent profiles of PTSD solely in victims with PTSD.

PURPOSE AND METHOD

This study investigates the possible presence of PTSD subtypes using latent class analysis (LCA) across two distinct trauma samples meeting caseness for DSM-5 PTSD based on self-reports (N = 787). Moreover, we assessed if a number of risk factors resulted in an increased probability of membership in a dissociative compared with a non-dissociative PTSD class.

RESULTS

The results of LCA revealed a two-class solution with two highly symptomatic classes: a dissociative class and a non-dissociative class across both samples. Increased emotion-focused coping increased the probability of individuals being grouped into the dissociative class across both samples. Social support reduced the probability of individuals being grouped into the dissociative class but only in the victims of motor vehicle accidents (MVAs) suffering from whiplash.

CONCLUSIONS

The results are discussed in light of their clinical implications and suggest that the dissociative subtype can be identified in victims of incest and victims of MVA suffering from whiplash meeting caseness for DSM-5 PTSD.

Does highly symptomatic class membership in the acute phase predict highly symptomatic classification in victims 6 months after traumatic exposure?

Recently studies have indicated the existence of both posttraumatic stress disorder (PTSD) and acute stress disorder (ASD) subtypes but no studies have investigated their mutual association. Although ASD may not be a precursor of PTSD per se, there are potential benefits associated with early identification of victims at risk of developing PTSD subtypes. The present study investigates ASD and PTSD subtypes using latent class analysis (LCA) following bank robbery (N=371). Moreover, we assessed if highly symptomatic ASD and selected risk factors increased the probability of highly symptomatic PTSD. The results of LCA revealed a three class solution for ASD and a two class solution for PTSD. Negative cognitions about self (OR=1.08), neuroticism (OR=1.09) and membership of the 'High symptomatic ASD' class (OR=20.41) significantly increased the probability of 'symptomatic PTSD' class membership. Future studies are needed to investigate the existence of ASD and PTSD subtypes and their mutual relationship.

Suicidal Ideation and Interpersonal Needs: Factor Structure of a Short Version of the Interpersonal Needs Questionnaire in an At-Risk Military Sample

OBJECTIVE

The interpersonal-psychological theory of suicide posits that perceived burdensomeness (PB; i.e., the belief that others would be better off if one were dead) and thwarted belongingness (TB; i.e., the belief that one lacks meaningful social connections) are both necessary risk factors for the development of suicidal ideation. To test these relations, measures are needed that are well validated, especially in samples of at-risk adults.

METHOD

The current study was designed to examine the factor structure of an eight-item version of the Interpersonal Needs Questionnaire (INQ) in a sample of 405 U.S. past and current military personnel (M_age = 31.57 years, SD = 7.28; 90.4% male) who endorsed either current suicidal ideation and/or a past suicide attempt. Analyses were conducted using confirmatory factor analysis (CFA).

RESULTS

A bifactor model comprising a general factor, labeled interpersonal needs, and two specific factors, labeled PB and TB, fit the data best. The general factor captured a high proportion of overall variance (81.9%). In contrast, the TB factor captured only a modest amount of variance in items meant to capture this factor (59.1%) and the PB factor captured very little variance in items meant to capture this factor (13.5%). Further, only the interpersonal needs factor was associated with lifetime and past-week suicidal ideation as well as suicidal ideation frequency and duration.

CONCLUSIONS

The current findings indicate that, for the INQ-8 in high-risk military personnel, a general interpersonal needs factor accounted for the relations PB and TB share with suicidal ideation.

Dimensional structure of DSM-5 posttraumatic stress symptoms in Spanish trauma victims

BACKGROUND

Confirmatory factor analytic studies have shown that posttraumatic stress disorder (PTSD) symptoms included in the fifth edition of the Diagnostic and Statistical Manual Disorders (DSM-5) may be better explained by two 6-factor models (the Externalizing Behaviours model and the Anhedonia model) and a 7-factor Hybrid model. The latter model comprises the symptom clusters of intrusion, avoidance, negative affect, anhedonia, externalizing behaviours, and anxious and dysphoric arousal. This model has received empirical support mainly in American samples. Of note, there have been a limited number of studies conducted on samples from other countries.

OBJECTIVE

This study aimed to examine the underlying dimensionality of DSM-5 PTSD symptoms in a Spanish clinical sample exposed to a range of traumatic events.

METHOD

Participants included 165 adults (78.8% females) seeking treatment in trauma services in the Madrid area (Spain). PTSD was assessed using the Global Assessment of Posttraumatic Stress Scale 5, a Spanish self-report instrument assessing posttraumatic symptoms according to the DSM-5 criteria. Confirmatory factor analyses were conducted in Mplus.

RESULTS

Both the 7-factor Hybrid model and the 6-factor Anhedonia model demonstrated good and equivalent fit to the data.

CONCLUSIONS

The findings of this study replicate and extend previous research by providing support for both the 7-factor Hybrid model and the 6-factor Anhedonia model in a clinical sample of Spanish trauma survivors. Given equivalent fit for these two models and the fewer number of latent factors in the Anhedonia model, it was selected as optimal in a traumatized Spanish sample. Implications and future research directions are discussed.

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.

Confirmatory factor analyses of DSM-5 posttraumatic stress disorder symptoms in psychiatric samples differing in Criterion A status

We examined the symptom structure of posttraumatic stress disorder (PTSD), as defined by American Psychiatric Association (2013. Diagnostic and statistical manual of mental disorders (DSM-5) (5th ed.). Washington, DC: Author). DSM-5 introduced notable changes to PTSD criteria, and the structural impact of these changes is unclear. We conducted confirmatory factor analyses comparing seven commonly investigated or recently proposed PTSD models in a large sample of interviewed psychiatric outpatients reporting a Criterion A trauma (n = 310) or a sub-threshold (non-Criterion A) stressful life event (n = 284). A novel six-factor dysphoria model and recently proposed seven-factor hybrid model outperformed other models and fit the data equally well in both groups. Our results suggest equal fit for both models, although the six-factor model is more parsimonious. These results have implications for research regarding the mechanisms underlying and the treatments targeting PTSD.

Assessing possible DSM-5 ASD subtypes in a sample of victims meeting caseness for DSM-5 ASD based on self-report following multiple forms of traumatic exposure

Acute stress disorder (ASD) was introduced into the DSM-IV to recognize early traumatic responses and as a precursor of PTSD. Although the diagnostic criteria for ASD were altered and structured more similarly to the PTSD definition in DSM-5, only the PTSD diagnosis includes a dissociative subtype. Emerging research has indicated that there also appears to be a highly symptomatic subtype for ASD. However, the specific nature of the subtype is currently unclear. The present study investigates the possible presence of ASD subtypes in a mixed sample of victims meeting caseness for DSM-5 ASD based on self-report following four different types of traumatic exposure (N=472). The results of latent profile analysis revealed a 5-class solution. The highly symptomatic class was marked by high endorsement on avoidance and dissociation compared to the other classes. Findings are discussed in regard to its clinical implications including the implications for the pending the ICD-11 and the recently released DSM-5.

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.

Temporal stability of DSM-5 posttraumatic stress disorder criteria in a problem-drinking sample

The 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) reformulated posttraumatic stress disorder (PTSD) based partially on research showing there were 4 main factors that underlie the symptoms of the disorder. The primary aim of this study was to examine the temporal stability of the DSM-5 factors as measured by the Posttraumatic Stress Disorder Checklist for DSM-5 (PCL-5; Weathers et al., 2010). Confirmatory factor analyses were conducted to examine the structure of DSM-5 PTSD, and temporal stability over 3 time points was examined to determine if the measure reflects a consistent construct over time. Our sample was 507 combat-exposed veterans of Iraq and Afghanistan who enrolled in an online intervention for problem drinking and combat-related stress (Brief et al., 2013). We administered the PCL-5 at baseline, 8-week postintervention, and 3-month follow-up assessments. The DSM-5 model provided an adequate fit to the data at baseline. Tests of equality of form and equality of factor loadings demonstrated stability of the factor structure over time, indicating temporal stability. This study confirmed the results of previous research supporting the DSM-5 model of PTSD symptoms (Elhai et al., 2012; Miller et al., 2013). This is the 1st study to demonstrate the temporal stability of the PCL-5, indicating its use in longitudinal studies measures the same construct over time.

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.

Assessing a dysphoric arousal model of acute stress disorder symptoms in a clinical sample of rape and bank robbery victims

BACKGROUND

Since the introduction of Acute Stress Disorder (ASD) into the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) research has focused on the ability of ASD to predict PTSD rather than focusing on addressing ASD's underlying latent structure. The few existing confirmatory factor analytic (CFA) studies of ASD have failed to reach a clear consensus regarding ASD's underlying dimensionality. Although, the discrepancy in the results may be due to varying ASD prevalence rates, it remains possible that the model capturing the latent structure of ASD has not yet been put forward. One such model may be a replication of a new five-factor model of PTSD, which separates the arousal symptom cluster into Dysphoric and Anxious Arousal. Given the pending DSM-5, uncovering ASD's latent structure is more pertinent than ever.

OBJECTIVE

USING CFA, FOUR DIFFERENT MODELS OF THE LATENT STRUCTURE OF ASD WERE SPECIFIED AND TESTED: the proposed DSM-5 model, the DSM-IV model, a three factor model, and a five factor model separating the arousal symptom cluster.

METHOD

The analyses were based on a combined sample of rape and bank robbery victims, who all met the diagnostic criteria for ASD (N = 404) using the Acute Stress Disorder Scale.

RESULTS

The results showed that the five factor model provided the best fit to the data.

CONCLUSIONS

The results of the present study suggest that the dimensionality of ASD may be best characterized as a five factor structure which separates dysphoric and anxious arousal items into two separate factors, akin to recent research on PTSD's latent structure. Thus, the current study adds to the debate about how ASD should be conceptualized in the pending DSM-5.