Construct validation of the hybrid model of posttraumatic stress disorder: Distinctiveness of the new symptom clusters

Assessing the psychometric properties of the Army STARRS' vertical unit cohesion scale: A large-scale, longitudinal study

Unit cohesion is the extent to which military service members feel committed to and supported by their military unit or, conversely, feel overlooked, neglected, and/or alienated. Unit cohesion reflects an important aspect of military social support and can act as a protective factor against mental health challenges, particularly in challenging situations. Theoretical suppositions and emerging evidence suggest that different types of unit support, specifically, vertical unit cohesion and horizontal unit cohesion, uniquely matter for service member well-being. Vertical unit cohesion (support from leaders in the unit and other higher-ranking positions) may be of universal importance to service members with implications for career progression and personal wellbeing, while horizontal unit cohesion (support from fellow unit members and peers) may be of importance under certain circumstances. Informed by the psychometric theory of scale development and validation, the dimensionality of unit cohesion theory, and the need for brief, sound measurement tools, this study first examined the psychometric properties of the Army STARRS four-item Vertical Unit Cohesion Scale in a longitudinal analysis with a large, diverse sample of Soldiers from the Pre/Post Deployment Study component of the Army STARRS dataset (N = 10,116). Then, exploratory analyses were conducted to examine the properties of the Horizontal Unit Cohesion Scale and understand the relationship between vertical and horizontal unit cohesion. Strong evidence for the Vertical Unit Cohesion Scale's psychometric soundness was established regarding factor structure, measurement invariance overtime, and construct validity. Conversely, preliminary evidence suggests that the three-item measure of Horizontal Unit Cohesion should be used with caution. Implications for researchers and military leadership are provided.

The German PCL-5: evaluating structural validity in a large-scale sample of the general German population

Background: In attempts to elucidate PTSD, recent factor analytic studies resulted in complex models with a proliferating number of factors that lack psychometrical and clinical utility. Recently, suggestions have been made to optimize factor analytic practices to meet a refined set of statistical and psychometric criteria.Objective: This study aims to assess the factorial structure of the German version of the PCL-5, implementing recent methodological advancements to address the risk of overfitting models. In doing so we diverge from traditional factor analytical research on PTSD.Method: On a large-scale sample of the German general population (n = 1625), exploratory factor analyses were run to investigate the dimensionality found within the data. Subsequently, we validated and compared all model suggestions from our preliminary analyses plus all standard and common alternative PTSD factor models (including the ICD-11 model) from previous literature with confirmatory factor analyses. We not only consider model fit indices based on WLSMV estimation but also deploy criteria such as favouring less complex models with a parsimonious number of factors, sufficient items per factor, low inter-factor correlations and number of model misspecifications.Results: All tested models showed adequate to excellent fit in respect to traditional model fit indices; however, models with two or more factors increasingly failed to meet other statistical and psychometric criteria.Conclusion: Based on the results we favour a two-factor bifactor model with a strong general PTSD factor and two less dominant specific factors - one factor with trauma-related symptoms (re-experiencing and avoidance) and one factor with global psychological symptoms (describing the trauma's higher-order impact on mood, cognition, behaviour and arousal).From the perspective of clinical utility, we recommend the cut-off scoring method for the German version of the PCL-5. Basic psychometric properties and scale characteristics are provided.

A Bifactor Model of General and Specific PTSD Symptom Change During Treatment

Posttraumatic stress disorder (PTSD) consists of four main components in the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5): intrusions (INT), avoidance (AV), negative alterations in cognition and mood (NACM), and arousal and reactivity (AAR); however, studies do not always support this four-factor model. A sample of 348 treatment-seeking adults was assessed for PTSD symptoms at baseline (Time 1) and then 12 weeks later (Time 2). Confirmatory factor analysis (CFA) was used to examine the model fit of the DSM-5 four-factor model of PTSD with and without a general factor at both time points, and structural equation modeling allowed for examination of these associations between time points. The four-factor model did not meet the criteria for excellent model fit, and the bifactor model provided improved model fit. The NACM specific factor did not meet the criteria for unique variance above and beyond the general factor. The bifactor model of PTSD symptoms was reliable over time, and both the general factor and the AAR factor significantly predicted subsequent symptom severity.

The Posttraumatic Stress Disorder (PTSD) Checklist for DSM-5: A Systematic Review of Existing Psychometric Evidence

The PTSD Checklist for DSM-5 (PCL-5) is a widely used self-rated measure of DSM-5 PTSD symptoms. The goal of this systematic review was to synthesize research on the psychometric properties of the PCL-5 to guide clinical and research applications. We focused on reliability, validity, factor structure, optimal cutoff scores, and sensitivity to clinical change indices. A systematic review of the literature following PRISMA guidelines was conducted using PubMed, PsycINFO, CINAHL, and PTSDpubs with search terms capturing selected psychometric indices of the PCL-5. The inclusion criteria were: peer-reviewed publication in English; primary focus on the PCL-5 psychometrics; empirical study; and study with adult samples. The search yielded 265 studies; 56 papers (amounting to 64 studies) met inclusion criteria and were reviewed. Findings generally indicated evidence for: acceptable internal consistency and test-retest reliability; construct validity; a 7-factor Hybrid Model; recommended cutoff scores between 31-33; and ability to index sensitivity to clinical change. To further advance knowledge and applications of the PCL-5, we need more research on abbreviated versions of the PCL-5, bifactor modeling as applied to the PCL-5, as well as on PCL-5 item difficulty estimates, discrimination parameters, and clinical change score estimates.

Longitudinal relationships among posttraumatic stress disorder symptom clusters in response to positive memory processing

BACKGROUND AND OBJECTIVES

Avoidance, inherent to posttraumatic stress disorder (PTSD) symptomatology, is theoretically and empirically linked to the maintenance of PTSD symptom severity. While research indicates traumatized individuals avoid positive and trauma memories, several PTSD treatments focus exclusively on traumatic memories. We examined the mediating role of PTSD's avoidance in the relationship between processing positive memories and PTSD cluster severity (intrusion, mood/cognitions, arousal).

METHODS

Sixty-five trauma-exposed college students (M_age = 22.52; 86.10% female) were randomly assigned to 3 conditions: narrating/processing, writing/processing, or control (same task across baseline [T0] and follow-up [T1]).

RESULTS

Half-longitudinal mediation models indicated participation in the narrating vs. writing and control conditions predicted decreases in T1 intrusion severity via reduction in T1 avoidance severity. Similarly, participation in the narrating vs. writing and control conditions predicted decreases in T1 mood/cognitions' severity via reduction in T1 avoidance severity. Participation in the narrating vs. writing condition predicted decreases in T1 arousal severity via reduction in T1 avoidance severity.

LIMITATIONS

Data was obtained from an analogue small-size sample of university students. In addition, sessions were only 6-8 days apart, with the processing component of each session lasting ∼30 min.

CONCLUSIONS

Processing positive memories may relate to lower PTSD severity via a reduction in PTSD's avoidance, paralleling effects of processing trauma memories. Our findings support future investigations of the mechanisms underlying impacts of positive memory processing in the context of PTSD treatments.

Disentangling the association between PTSD symptom heterogeneity and alcohol use disorder: Results from the 2019-2020 National Health and Resilience in Veterans Study

Veterans are at increased risk of comorbid posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) relative to civilians. Few studies have explored the association between distinct PTSD symptoms and AUD in veterans, and existing findings are highly discrepant. This study aimed to address this gap and equivocal association by evaluating which PTSD symptom clusters are most associated with AUD in a veteran sample using the 7-factor 'hybrid' model of PTSD. Data were analyzed from the 2019-2020 National Health and Resilience in Veterans Study (NHRVS), a nationally representative survey of 4069 U.S. veterans. Veterans completed self-report measures to assess current PTSD symptoms and AUD. Multivariable logistic regression and relative importance analyses were conducted to examine associations between the 7-factor model of PTSD symptoms and AUD. Adjusting for sociodemographic, military, trauma factors, and depressive symptoms, scores on the dysphoric arousal (20.7% relative variance explained [RVE]) and externalizing behaviors (19.0% RVE) symptom clusters were most strongly associated with AUD in the full sample, while externalizing behaviors (47.7% RVE), anxious arousal (23.9% RVE), and dysphoric arousal (12.4%) accounted for the majority of explained variance in veterans who screened positive for PTSD. Results of this nationally representative study of U.S. veterans highlight the importance of externalizing behaviors and arousal symptoms of PTSD as potential drivers of AUD in this population. The 7-factor hybrid model of PTSD provides a more nuanced understanding of PTSD-AUD associations, and may help inform risk assessment and more personalized treatment approaches for veterans with and at-risk for AUD.

A Bayesian Structural Equation Modeling Factor Analysis of the UCLA Posttraumatic Stress Disorder Reaction Index for DSM-5 in a Polyvictimized Sample of Adolescents

The revised criteria for posttraumatic stress disorder (PTSD) in the fifth edition of the Diagnostic and Statistical Manual necessitated the development of new screening tools for youth, one of the most widely used of which is the UCLA Posttraumatic Stress Disorder Reaction Index for DSM-5 (RI-5). Thus far, the few studies that have investigated the RI-5's factor structure have supported a four-factor model. However, to date this research has been limited to youth with histories of exposure to single-event traumatic stressors, a significant limitation as evidence suggests many trauma-exposed youth report exposure to multiple types of traumatic stressors, or polyvictimization. It is imperative to determine the generalizability of previous factor models to specific populations which they are purported to represent. We investigated whether the RI-5's four-factor model replicated in a sample of 455 polyvictimized justice-involved adolescents. Initial confirmatory factor analysis demonstrated that the four-factor model did not converge. Therefore, we utilized Bayesian Structural Equations Modeling (BSEM) to determine why the previously proposed factor structure did not converge. The BSEM model suggested that the global factor structure was acceptable and did not require addition or subtraction of any factor or cross-factor loadings. However, small and moderate residual covariances resulted in model misspecification, suggesting there may be additional associations not captured by the current DSM-5 model for polyvictimized youth. Future work should continue examining the RI-5's factor structure in order to better understand whether the current results are unique and how measurements assessing DSM-5 PTSD symptom criteria perform in diverse trauma-exposed youth populations.

DSM-5-TR prolonged grief disorder and DSM-5 posttraumatic stress disorder are related, yet distinct: confirmatory factor analyses in traumatically bereaved people

BACKGROUND

Prolonged grief disorder (PGD) is newly included in the text revision of the DSM-5 (DSM-5-TR). So far, it is unknown if DSM-5-TR PGD is distinguishable from bereavement-related posttraumatic stress disorder (PTSD). Prior research examining the distinctiveness of PTSD and pathological grief focused on non-traumatic loss samples, used outdated conceptualizations of grief disorders, and has provided mixed results.

OBJECTIVE

In a large sample of traumatically bereaved people, we first evaluated the factor structure of PTSD and PGD separately and then evaluated the factor structure when combining PTSD and PGD symptoms to examine the distinctiveness between the two syndromes.

METHODS

Self-reported data were used from 468 people bereaved due to the MH17 plane disaster (N = 200) or a traffic accident (N = 268). The 10 DSM-5-TR PGD symptoms were assessed with the Traumatic Grief Inventory-Self Report Plus (TGI-SR+). The 20-item Posttraumatic Stress Disorder Checklist for DSM-5 (PCL-5) was used to tap PTSD symptoms. Confirmatory factor analyses were conducted.

RESULTS

For PTSD, a seven factor, so-called 'Hybrid' model yielded the best fit. For PGD, a univariate factor model fits the data well. A combined model with PGD items loading on one factor and PTSD items on seven factors (associations between PGD and PTSD subscales r ≥ .50 and ≤.71), plus a higher-order factor (i.e. PTSD factors on a higher-order PTSD factor) (association between higher-order PTSD factor and PGD factor r = .82) exhibited a better fit than a model with all PGD and PTSD symptom loading on a single factor or two factors (i.e. one for PGD and one for PTSD).

CONCLUSIONS

This is the first study examining the factor structure of DSM-5-TR PGD and DSM-5 PTSD in people confronted with a traumatic loss. The findings provide support that PGD constitutes a syndrome distinguishable from, yet related with, PTSD.

The utility of college student samples in research on trauma and posttraumatic stress disorder: A critical review

There is a widespread notion of the 'college sophomore problem' in social science research that posits that college student samples are samples of convenience with little generalizability to the general population. To address this concern, we conducted a critical review of the literature on college student samples in trauma research. Specifically, we reviewed how college student samples differ from non-college samples in four key areas of trauma research: (1) exposure rates to potentially traumatic events (PTEs), (2) prevalence of posttraumatic stress disorder (PTSD) symptoms, (3) factor structure of PTSD symptoms, and (4) PTSD's relation with common markers, correlates, and consequences. Lastly, we discussed the value and advantages of using college student samples in trauma research. Results of the critical review indicated similar trends of trauma-related findings (Points 1-4) between college student samples and both U.S. nationally collected and treatment-seeking samples; specifically, we identified a comparable lifetime PTE exposure rate, comparable rates of PTSD, a comparable factor structure of PTSD symptoms, and a comparable pattern of associations between PTSD symptoms and post-trauma markers/correlates/consequences. Although trauma-exposed college student samples are biased in some key areas, they may be no more biased than other commonly used trauma samples (e.g. epidemiological, treatment-seeking). Results of this critical review highlight the need to re-examine potentially unfounded biases on the part of the trauma research community, as well as the need to consider advantages of using college student samples in trauma research.

The Detailed Assessment of Posttraumatic Stress-Second Edition (DAPS-2): Initial Psychometric Evaluation in an MTurk-Recruited, Trauma-Exposed Community Sample

The Detailed Assessment of Posttraumatic Stress (DAPS; Briere, 2001) is a comprehensive questionnaire that assesses posttraumatic stress disorder (PTSD) diagnostic criteria as well as peritraumatic responses and associated problems such as dissociation, suicidality, and substance abuse. DAPS scores have demonstrated excellent reliability, validity, and clinical utility, performing as well or better than leading PTSD questionnaires. The present study was an initial psychometric evaluation of the unreleased DAPS (DAPS-2), revised for Diagnostic and Statistical Manual of Mental Disorders-Fifth edition (DSM-5), in an MTurk-recruited mixed trauma sample (N = 367). DAPS-2 PTSD scale and associated features scales demonstrated high internal consistency and strong convergent and discriminant validity. In confirmatory factor analyses, the DSM-5 four-factor model of PTSD provided adequate fit, but the leading seven-factor model provided superior fit. These results indicate the DAPS-2 is a psychometrically sound measure of DSM-5 PTSD symptoms.

Relation of positive memory recall count and accessibility with post-trauma mental health

Positive memory encoding and retrieval deficits have an empirical relation with several post-trauma outcomes. Drawing from the Contractor et al. model, we examined relations between positive memory characteristics and post-trauma mental health indicators. A trauma-exposed community sample of 203 participants (Mage = 35.40 years; 61.10% female) was recruited via Amazon's Mechanical Turk. Participants completed measures of posttraumatic stress disorder (PTSD; PTSD Checklist for DSM-5), depression (Patient Health Questionnaire-9), posttraumatic cognitions (Posttraumatic Cognitions Inventory), affect (Positive and Negative Affect Schedule), count/number of recalled specific positive memories (Autobiographical Memory Test) and accessibility of a specific positive memory (i.e., subjective ease of recalling details of a memory; Memory Experiences Questionnaire-Short Form). Linear regression results indicated that PTSD intrusion severity, PTSD negative alterations in cognitions and mood (NACM) severity, PTSD alterations in arousal and reactivity (AAR) severity, self-blame, and positive affect significantly and negatively predicted the count of specific positive memories. Further, PTSD NACM severity, PTSD AAR severity, negative cognitions about the self, and negative affect significantly and negatively predicted accessibility of a specific positive memory. Thus, count/accessibility of specific positive memories was associated with several post-trauma mental health indicators; this highlights the relevance and potential impact of integrating positive memories into trauma treatment.

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.

Chromosomes to Social Contexts: Sex and Gender Differences in PTSD

PURPOSE OF REVIEW

This review highlights recent research on sex- and gender-related factors in the prevalence, symptom expression, and treatment of PTSD. Further discoveries about the underlying mechanisms of sex and gender effects have the potential to shape innovative directions for research.

RECENT FINDINGS

The prevalence of PTSD is substantially higher among women, but women show a modest advantage with respect to treatment response. There is evidence of greater heritability among females. Women are more likely to experience sexual and intimate violence, childhood trauma exposure, and repeated trauma exposures. Specific characteristics of social contexts act as gender-linked risks for PTSD. Among individuals diagnosed with PTSD, men and women are similar in phenotypic expression. Though research has yet to fully account for the factors that explain sex- and gender- related effects on PTSD, emerging research suggests these effects occur across multiple levels. Shared risk factors for trauma exposure and PTSD merit further investigation. Both social and biological contexts merit investigation to understand sex-linked differences in heritability.

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.

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.