Latent dimensions of posttraumatic stress disorder and their relations with alcohol use disorder.

PURPOSE: The objective of this study was to evaluate the relationship between factors of posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) using confirmatory factor analysis (CFA) in order to further our understanding of the substantial comorbidity between these two disorders. METHODS: CFA was used to examine which factors of PTSD's dysphoria model were most related to AUD in a military sample. Ohio National Guard soldiers with a history of overseas deployment participated in the survey (n = 1215). Participants completed the PTSD Checklist and a 12-item survey from the National Survey on Drug Use used to diagnosis AUD. RESULTS: The results of the CFA indicated that a combined model of PTSD's four factors and a single AUD factor fit the data very well. Correlations between PTSD's factors and a latent AUD factor ranged from correlation coefficients of 0.258-0.285, with PTSD's dysphoria factor demonstrating the strongest correlation. However, Wald tests of parameter constraints revealed that AUD was not more correlated with PTSD's dysphoria than other PTSD factors. CONCLUSIONS: All four factors of PTSD's dysphoria model demonstrate comparable correlations with AUD. The role of dysphoria to the construct of PTSD is discussed.

Dimensional structure of DSM-5 posttraumatic stress symptoms: support for a hybrid Anhedonia and Externalizing Behaviors model.

Several revisions to the symptom clusters of posttraumatic stress disorder (PTSD) have been made in the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Central to the focus of this study was the revision of PTSD's tripartite structure in DSM-IV into four symptom clusters in DSM-5. Emerging confirmatory factor analytic (CFA) studies have suggested that DSM-5 PTSD symptoms may be best represented by one of two 6-factor models: (1) an Externalizing Behaviors model characterized by a factor which combines the irritability/anger and self-destructive/reckless behavior items; and (2) an Anhedonia model characterized by items of loss of interest, detachment, and restricted affect. The current study conducted CFAs of DSM-5 PTSD symptoms assessed using the PTSD Checklist for DSM-5 (PCL-5) in two independent and diverse trauma-exposed samples of a nationally representative sample of 1484 U.S. veterans and a sample of 497 Midwestern U.S. university undergraduate students. Relative fits of the DSM-5 model, the DSM-5 Dysphoria model, the DSM-5 Dysphoric Arousal model, the two 6-factor models, and a newly proposed 7-factor Hybrid model, which consolidates the two 6-factor models, were evaluated. Results revealed that, in both samples, both 6-factor models provided significantly better fit than the 4-factor DSM-5 model, the DSM-5 Dysphoria model and the DSM-5 Dysphoric Arousal model. Further, the 7-factor Hybrid model, which incorporates key features of both 6-factor models and is comprised of re-experiencing, avoidance, negative affect, anhedonia, externalizing behaviors, and anxious and dysphoric arousal symptom clusters, provided superior fit to the data in both samples. Results are discussed in light of theoretical and empirical support for the latent structure of DSM-5 PTSD symptoms.

Preliminary study on the relationship between visitation in the emergency department and posttraumatic mental health.

This study documented family/friend support to patients in the Emergency Department (ED), including bedside visits and transportation of patients from the ED after discharge, and measured depression, anxiety, and stress symptoms within 2 weeks, 1 month and 3 months after motor vehicle accidents. Stress and depression symptoms significantly decreased during the initial three months. Family/friend visitation in the ED was negatively associated with anxiety and depression symptoms within 2 weeks and with stress symptoms months after trauma. This pilot study suggests family/friend visitation in the ED is associated with fewer mental health issues in the months following an accident.

Changes in the Beck Depression Inventory-II's underlying symptom structure over 1 month of inpatient treatment.

Research has not investigated changes in the symptom structure of depression over the course of mental health treatment. In the present study, 1025 psychiatric inpatients were recruited and assessed for depression symptom severity using the Beck Depression Inventory-II (BDI-II) at admission and after 1 month of treatment. A three-factor BDI-II model was tested using confirmatory factor analysis and fit reasonably well at both time points. Measurement invariance testing results demonstrated that factor loadings increased, indicating that the meaning of the three underlying depression dimensions changed through treatment. However, observed variable intercepts and residual error variances decreased significantly after 1 month of treatment, reflecting decreases in symptom severity as well as measurement error. Thus, depressive symptom severity decreased over the course of treatment, and the underlying factor structure of depression improved in fit after treatment. Implications for changes to the structure of depression symptoms and in the clinical practice of tracking depression over time are discussed.

Relations between the underlying dimensions of PTSD and major depression using an epidemiological survey of deployed Ohio National Guard soldiers.

BACKGROUND: In the present study, the authors investigated the relationship between the underlying symptom dimensions of posttraumatic stress disorder (PTSD) and dimensions of major depressive disorder (MDD). METHOD: A sample of 1266 Ohio National Guard soldiers with a history of overseas deployment participated and were administered the PTSD Checklist (assessing PTSD) and Patient Health Questionnaire-9 (assessing depression). RESULTS: Using confirmatory factor analysis, results demonstrated that both PTSD's dysphoria and hyperarousal factors were more related to depression's somatic than non-somatic factor. Furthermore, depression's somatic factor was more related to PTSD's dysphoria than hyperarousal factor. LIMITATIONS: Limitations of this study include the use of self-report measures and a predominately male military sample. CONCLUSIONS: Results indicate that PTSD's dysphoria factor is related to depression specifically by way of depression's somatic construct. Given PTSD's substantial dysphoria/distress component, these results have implications for understanding the nature of PTSD's high comorbidity with depression.

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.

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.

Posttraumatic stress disorder instrument wording content is associated with differences in factor structure.

The authors examined posttraumatic stress disorder (PTSD) item wording differences on the factor structure of PTSD. Nonclinical, trauma-exposed participants were randomly assigned to complete a PTSD measure using item wording content from the PTSD Checklist (n = 182) or PTSD Symptom Scale (n = 203). Compared to the 4-factor emotional numbing PTSD model, the 4-factor dysphoria PTSD model fit best across groups based on smaller Bayesian information criterion (BIC) values. For PTSD Checklist participants, the numbing model's BIC was 6238.54 compared to the dysphoria model's BIC of 6156.03. For the PTSD Symptom Scale, the numbing model's BIC was 6161.38 compared to the dysphoria model's BIC of 6102.87. Groups differed on variable intercepts and residual variances. Instrument and construct implications are discussed.

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.

Posttraumatic stress disorder's frequency and intensity ratings are associated with factor structure differences in military veterans.

We examined possible differences in the factor structure of posttraumatic stress disorder (PTSD) on the basis of whether frequency or intensity symptom response formats were used to assess PTSD. Participants included 669 veterans recruited from an epidemiological study of four Veterans Affairs Medical Centers' primary care clinics in the southeastern United States. Confirmatory factor analysis using measurement invariance testing found that the frequency and intensity symptom formats were significantly different from each other on PTSD's factor structure parameters, including factor loadings, observed variable intercepts, and measurement errors. The only exception was for PTSD's effortful avoidance symptoms, which were associated with equivalent parameter estimates for both the frequency and intensity formats. Implications for the clinical assessment of PTSD and interpretation of the extant literature base on PTSD's factor structure are considered.

A case study of salami slicing: pooled analyses of duloxetine for depression.

BACKGROUND: Publishing separate, yet very similar pieces of a single dataset across multiple papers is known as 'salami slicing'. This practice may be motivated by researchers wishing to increase their publication counts and by the desire to increase exposure of their findings. 'Salami slicing' may also be used by the drug industry to help widely disseminate positive findings regarding its products. Journal editors across many scientific disciplines have bemoaned such duplicative publications on several occasions. However, little research has been conducted on the frequency of such publication practices, and findings have been inconsistent. No research has investigated whether 'salami slicing' may also occur in publications presenting results from pooled analyses of clinical trials. METHODS: We examined the scientific literature on duloxetine as a treatment for depression, examining how data from clinical trials were reported across 43 pooled analyses. RESULTS: The vast majority of pooled analyses (88%) had at least one author who was employed by the manufacturer of duloxetine. Several pooled analyses based on highly overlapping clinical trials presented efficacy and safety data that did not answer unique research questions, and thus appeared to qualify as salami publications. Six clinical trials had their data utilized as part of 20 or more separately published pooled analyses. CONCLUSIONS: Such redundant publications add little to scientific understanding and represent a poor use of peer reviewer and editorial resources.