Dissociative subtype of DSM-5 posttraumatic stress disorder in U.S. veterans

The Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) formally introduced a dissociative subtype of posttraumatic stress disorder (PTSD). This study examined the proportion of U.S. veterans with DSM-5 PTSD that report dissociative symptoms; and compared veterans with PTSD with and without the dissociative subtype and trauma-exposed controls on sociodemographics, clinical characteristics, and quality of life. Multivariable analyses were conducted on a nationally representative sample of 1484 veterans from the National Health and Resilience in Veterans Study (second baseline survey conducted September–October, 2013). Of the 12.0% and 5.2% of veterans who screened positive for lifetime and past-month DSM-5 PTSD, 19.2% and 16.1% screened positive for the dissociative subtype, respectively. Among veterans with PTSD, those with the dissociative subtype reported more severe PTSD symptoms, comorbid depressive and anxiety symptoms, alcohol use problems, and hostility than those without the dissociative subtype. Adjusting for PTSD symptom severity, those with the dissociative subtype continued to report more depression and alcohol use problems. These results underscore the importance of assessing, monitoring, and treating the considerable proportion of veterans with PTSD and dissociative symptoms.     

Assessing the structure and meaningfulness of the dissociative subtype of PTSD

Purpose

Studies conducted in the USA, Canada and Denmark have supported the existence of the dissociative PTSD subtype, characterized primarily by symptoms of depersonalization and derealization. The current study aimed to examine the dissociative PTSD subtype in an Eastern European, predominantly female (83.16%) sample, using an extended set of dissociative symptoms.

Methods

A latent profile analysis was applied to the PTSD and dissociation data from 689 trauma-exposed university students from Slovakia.

Results

Four latent profiles of varying PTSD and dissociation symptomatology were uncovered. They were named non-symptomatic, moderate PTSD, high PTSD and dissociative PTSD. The dissociative PTSD profile showed elevations on depersonalization and derealization, but also the alternative dissociative indicators of gaps in awareness and memory, sensory misperceptions and cognitive and behavioural re-experiencing. The core PTSD symptoms of ‘memory impairment’ and ‘reckless or self-destructive behaviour’ were also significantly elevated in the dissociative PTSD profile. Moreover, anxiety and anger predicted membership in the dissociative PTSD profile.

Conclusion

The results provide support for the proposal that the dissociative PTSD subtype can be characterized by a variety of dissociative symptoms.

     

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 DSM-5 dissociative-PTSD subtype: Can levels of depression,anxiety, hostility,and sleeping difficulties differentiate between dissociative-PTSD and PTSD in rape and sexual assault victims?

The DSM-5 currently includes a dissociative-PTSD subtype within its nomenclature. Several studies have confirmed the dissociative-PTSD subtype in both American Veteran and American civilian samples. Studies have begun to assess specific factors which differentiate between dissociative vs. non-dissociative PTSD. The current study takes a novel approach to investigating the presence of a dissociative-PTSD subtype in its use of European victims of sexual assault and rape (N = 351). Utilizing Latent Profile Analyses, we hypothesized that a discrete group of individuals would represent a dissociative-PTSD subtype. We additionally hypothesized that levels of depression, anger, hostility, and sleeping difficulties would differentiate dissociative-PTSD from a similarly severe form of PTSD in the absence of dissociation. Results concluded that there were four discrete groups termed baseline, moderate PTSD, high PTSD, and dissociative-PTSD. The dissociative-PTSD group encompassed 13.1% of the sample and evidenced significantly higher mean scores on measures of depression, anxiety, hostility, and sleeping difficulties. Implications are discussed in relation to both treatment planning and the newly published DSM-5.     

The co-occurrence of PTSD and dissociation: differentiating severe PTSD from dissociative-PTSD

Purpose

A dissociative-posttraumatic stress disorder (PTSD) subtype has been included in the DSM-5. However, it is not yet clear whether certain socio-demographic characteristics or psychological/clinical constructs such as comorbid psychopathology differentiate between severe PTSD and dissociative-PTSD. The current study investigated the existence of a dissociative-PTSD subtype and explored whether a number of trauma and clinical covariates could differentiate between severe PTSD alone and dissociative-PTSD.

Methods

The current study utilized a sample of 432 treatment seeking Canadian military veterans. Participants were assessed with the Clinician Administered PTSD Scale (CAPS) and self-report measures of traumatic life events, depression, and anxiety. CAPS severity scores were created reflecting the sum of the frequency and intensity items from each of the 17 PTSD and 3 dissociation items. The CAPS severity scores were used as indicators in a latent profile analysis (LPA) to investigate the existence of a dissociative-PTSD subtype. Subsequently, several covariates were added to the model to explore differences between severe PTSD alone and dissociative-PTSD.

Results

The LPA identified five classes: one of which constituted a severe PTSD group (30.5 %), and one of which constituted a dissociative-PTSD group (13.7 %). None of the included, demographic, trauma, or clinical covariates were significantly predictive of membership in the dissociative-PTSD group compared to the severe PTSD group.

Conclusions

In conclusion, a significant proportion of individuals report high levels of dissociation alongside their PTSD, which constitutes a dissociative-PTSD subtype. Further investigation is needed to identify which factors may increase or decrease the likelihood of membership in a dissociative-PTSD subtype group compared to a severe PTSD only group.     

A more proximal impact of dissociation than of trauma and posttraumatic stress disorder on schneiderian symptoms in patients diagnosed with schizophrenia

Background

Dissociation is often related to psychologic trauma and is also commonly correlated with posttraumatic stress disorder (PTSD). Schneiderian symptoms occur in dissociative disorder and PTSD, whereas dissociation and trauma are also frequent in patients with schizophrenia. Dissociation and schneiderian symptoms may reflect posttraumatic symptomatology in some patients diagnosed with schizophrenia who might not develop PTSD.

Method

Seventy-one patients completed an interview assessing symptoms of schizophrenia, depression, dissociative disorder, and PTSD. Data were collected using the Positive and Negative Syndrome Scale, the Montgomery-Asberg Depression Rating Scale, the Arbeitsgemeinschaft Methodik und Dokumentation in der Psychiatrie scale for dissociation, and a Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition-based questionnaire. Multiple analysis of covariance was used to compare psychopathologic measures between groups with or without PTSD criteria A1 and A2, PTSD, and high and low levels of dissociation, controlling for substance abuse.

Result

Trauma and dissociation were associated with more severe symptoms of schizophrenia. Especially high dissociation was associated with an increase in symptom load, whereas criterion A and PTSD had little or no such effect.

Discussion

In the present study, those with more severe schizophrenic and depressive symptoms were also characterized by high dissociation. The possible relation to trauma and schizophrenic diathesis is discussed along with the limitations of the study.     

Childhood trauma and dissociation in first-episode psychosis,chronic schizophrenia and community controls

Increasing evidence supports the role of childhood trauma in the etiology of psychosis but underlying mechanisms are poorly understood. Early maltreatment has been linked to dissociative symptoms in psychosis patients. We explored associations between childhood trauma (Childhood Trauma Questionnaire) and dissociation (Dissociative Experiences Scale) in first-episode psychotic patients (n=62), chronic psychotic patients (n=43), and non-psychotic community controls (n=66). Multivariate analyses of covariance were used to test associations between childhood trauma and dissociation by group while controlling for sex. Chronic patients reported the highest level of dissociation. More severe childhood trauma was associated with greater dissociative symptoms in all groups although most strongly in chronic patients. Emotional abuse showed the strongest associations with dissociation, with these being strongest for chronic patients, followed by first-episode patients — and least for controls. Men showed a stronger association between physical neglect and dissociation than women, irrespective of group. There were no significant group by sex interactions. Our findings replicate the strong association between childhood trauma and dissociative symptoms in chronic and first-episode psychotic patients relative to non-psychotic control subjects. We also demonstrate the salience of emotional abuse in explaining variance in dissociation, especially in chronic patients.     

Resting‐state functional connectivity of the bed nucleus of the stria terminalis in post‐traumatic stress disorder and its dissociative subtype

The bed nucleus of the stria terminals (BNST) is a subcortical structure involved in anticipatory and sustained reactivity to threat and is thus essential to the understanding of anxiety and stress responses. Although chronic stress and anxiety represent a hallmark of post‐traumatic stress disorder (PTSD), to date, few studies have examined the functional connectivity of the BNST in PTSD. Here, we used resting state functional Magnetic Resonance Imaging (fMRI) to investigate the functional connectivity of the BNST in PTSD (n = 70), its dissociative subtype (PTSD + DS) (n = 41), and healthy controls (n = 50). In comparison to controls, PTSD showed increased functional connectivity of the BNST with regions of the reward system (ventral and dorsal striatum), possibly underlying stress‐induced reward‐seeking behaviors in PTSD. By contrast, comparing PTSD + DS to controls, we observed increased functional connectivity of the BNST with the claustrum, a brain region implicated in consciousness and a primary site of kappa‐opioid receptors, which are critical to the dynorphin‐mediated dysphoric stress response. Moreover, PTSD + DS showed increased functional connectivity of the BNST with brain regions involved in attention and salience detection (anterior insula and caudate nucleus) as compared to PTSD and controls. Finally, BNST functional connectivity positively correlated with default‐mode network regions as a function of state identity dissociation, suggesting a role of BNST networks in the disruption of self‐relevant processing characterizing the dissociative subtype. These findings represent an important first step in elucidating the role of the BNST in aberrant functional networks underlying PTSD and its dissociative subtype.     

Are PTSD and autistic traits related? An examination among typically developing Israeli adults

Background and objectivesPrevious research indicates that individuals with Autism Spectrum Disorder (ASD) face an increased risk of experiencing traumatic events. Autistic Traits (AT), characteristic of ASD, are continuously distributed across the general population. Our main objective was to examine the association between AT and PTSD (Post Traumatic Stress Disorder), a topic rarely assessed before.MethodsOne hundred and three college students from 3 academic areas, previously found to be associated with different degrees of AT, completed self-report questionnaires tapping PTSD (the PCL-5; PTSD Checklist for DSM-5), AT (AQ; the Autism Spectrum Quotient), and traumatic life events.ResultsAT were positively associated with all PTSD symptom clusters, except for avoidance. The association between imagination difficulties and PTSD was moderated by gender. Among participants meeting the PTSD cutoff, those with the highest AT levels reported a PTSD symptomatic profile with an increased dominance of hyper-arousal symptoms.ConclusionsThe AT-PTSD association reported here may be attributed to several factors, including increased victimization associated with AT, as well as shared vulnerability factors for both conditions, including impairments in social cognition. Further research is needed in order to understand the associations between these two conditions, considering gender differences, and possible shared underlying mechanisms.     

An item response theory analysis of the PTSD checklist for DSM-5: Implications for DSM-5 and ICD-11

The PTSD Checklist (PCL) is a widely used, extensively validated questionnaire for posttraumatic stress disorder (PTSD). The PCL was revised for Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5; Friedman, 2013), and the updated version, the PCL-5, has continued the strong psychometric performance of the original version. To further explore the PCL-5’s psychometric properties, we used item response theory (IRT) to examine item difficulty and discrimination parameters in separate samples of trauma-exposed undergraduates (N = 1213) and community members (N = 367). Considering item difficulty, nightmares, flashbacks, and reckless or self-destructive behavior emerged among the most difficult items across samples and internal avoidance emerged as the least difficult items across samples. In terms of item discrimination, inability to experience positive emotions, detachment from others, diminished interest, and negative emotions emerged as highly discriminating items in both samples, and traumatic amnesia and reckless or self-destructive behavior emerged as the least discriminating items in both samples. These results have implications for the divergent conceptualizations of PTSD in DSM-5 versus International Classification of Diseases, 11th Edition (ICD-11; WHO, 2018). Future research should employ IRT in a clinical population.     

The underlying dimensions of DSM-5 posttraumatic stress disorder symptoms in an epidemiological sample of Chinese earthquake survivors

The current study investigated the underlying dimensions of DSM-5 PTSD symptoms in an epidemiological sample of Chinese earthquake survivors. The sample consisted of 810 females and 386 males, with a mean age of 47.9 years (SD = 10.0, range: 16–73). PTSD symptoms were assessed using the PTSD Checklist for DSM-5, and alternative models were evaluated with confirmatory factor analysis. Results indicated that a six-factor model comprised of intrusion, avoidance, negative affect, anhedonia, dysphoric arousal, and anxious arousal factors emerged as the best fitting model. The current findings add to limited literature on the latent structure of PTSD symptoms described in the recently released DSM-5, and carry implications for further trauma-related research and clinical practice.     

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 χ² 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.     

Differential effects of childhood abuse and neglect: mediation by posttraumatic distress in neurotic disorder and negative symptoms in schizophrenia?

Dissociation, though understood as a response to trauma, lacks a proven etiology. The assumption of a dose-response relationship between trauma, dissociation and Schneiderian symptoms led to the proposal of a dissociative subtype of schizophrenia characterized by severe child maltreatment, dissociation and psychosis. Child maltreatment and dissociation are common features of neurotic disorders as well, and the link between trauma, dissociation, and hallucinations is not specific for schizophrenia. This study compares childhood abuse and neglect, posttraumatic distress and adult dissociation in patients with psychotic vs. non-psychotic disorder. Thirty-five participants with non-psychotic disorder and twenty-five with schizophrenia were analyzed using the Scale for the Assessment of Positive Symptoms (SAPS), the Scale for the Assessment of Negative Symptoms (SANS), the Montgomery-Åsberg Depression Rating Scale (MADRS), the Posttraumatic Stress Diagnostic Scale PDS (PDS), the Childhood Trauma Questionnaire (CTO) and the Arbeitsgemeinschaft Methodik und Dokumentation in der Psychiatrie (AMDP)-module on dissociation. Trauma and clinical syndromes were compared by means of T-testing and logistic regression between 1) the diagnoses and 2) groups with and without post-traumatic stress disorder (PTSD), marked dissociation and psychotic symptoms. While non-psychotic disorder was related to abuse, schizophrenia showed an association with neglect. Childhood trauma predicted posttraumatic symptomatology and negative symptoms. Childhood abuse and neglect may effectuate different outcomes in neurotic and psychotic disorder. The underlying mechanisms, including dissociation, dovetail with cognitive, emotional and behavioural changes involved in depression, posttraumatic distress and chronic schizophrenia symptoms rather than being directly linked to trauma.     

PTSD,emotion dysregulation,and dissociative symptoms in a highly traumatized sample

Exposure to multiple traumas has been shown to result in many negative mental health outcomes, including posttraumatic stress disorder (PTSD). Dissociation, which involves disruptions in memory, identity, and perceptions, may be a component of PTSD, particularly among individuals who have experienced childhood trauma. Emotion regulation difficulties are also strongly associated with childhood trauma and emotion dysregulation may be a particularly important factor to consider in the development and maintenance of dissociative symptoms.The goal of the present study was to determine whether emotion dysregulation mediated the relationship between PTSD symptoms and dissociation in a sample of 154 (80% female, 97% African-American) adults recruited from a public, urban hospital. PTSD was measured using the Clinician Administered PTSD Scale, emotion dysregulation was measured using the Difficulties in Emotion Regulation Scale, and dissociation was measured using the Multiscale Dissociation Inventory. A linear regression analysis showed that both PTSD and emotion dysregulation were statistically significant predictors of dissociation even after controlling for trauma exposure. Alexithymia and an inability to use emotion regulation strategies in particular were predictive of dissociation above and beyond other predictor variables. Using bootstrapping techniques, we found that overall emotion dyregulation partially mediated the effect of PTSD symptoms on dissociative symptoms. Our results suggest that emotion dysregulation may be important in understanding the relation between PTSD and dissociative symptoms. Treatment approaches may consider a focus on training in emotional understanding and the development of adaptive regulation strategies as a way to address dissociative symptoms in PTSD patients.     

Relation between PTSD symptom clusters and positive memory characteristics: A network perspective

Positive memory characteristics relate to posttraumatic stress disorder (PTSD) severity. We utilized a network approach to examine relations between PTSD clusters (intrusions, avoidance, negative alterations in cognitions and mood [NACM], alterations in arousal and reactivity [AAR]) and positive memory characteristics (count, accessibility, valence, vividness, coherence, time perspective, sensory details). We identified differential relations between PTSD clusters and positive memory characteristics, and central/bridging symptoms. Participants were an Amazon Mechanical Turk-recruited sample of 206 individuals (M_age = 35.36; 61.20% females). We estimated a regularized Gaussian Graphic Model comprising four nodes representing the PTSD clusters and six nodes representing positive memory characteristics. Regarding cross-community relations, AAR (highest node strength) was negatively associated with positive memory count, valence, coherence, and accessibility; avoidance was positively and negatively associated with positive memory vividness and count respectively. The NACM-AAR and intrusion-avoidance edges were significantly stronger than most edges. From the PTSD community, AAR and avoidance had the highest bridge strength and bridge expected influence respectively; from the positive memory community, coherence and vividness had the highest bridge strength and bridge expected influence respectively. Results indicate the potential pivotal role of AAR, avoidance, coherence, and vividness in the PTSD-positive memory relation, which renders them assessment/treatment targets pending further investigation.     

Prevalence and associations of co-morbid insomnia and sleep apnoea in an Australian population-based sample

IntroductionInsomnia and obstructive sleep apnoea (OSA) are the two most prevalent sleep disorders, and frequently co-occur (COMISA) in sleep clinic samples. However, few studies have investigated the prevalence or associations of COMISA in the general population.MethodsWe used population-based online survey data from 2044 Australian adults. The prevalence and associations of insomnia, OSA and COMISA were investigated according to symptom-level, and disorder-level definitions. Insomnia was defined according to chronic difficulties initiating and/or maintaining sleep (DIMS; symptom-level), and ICSD-3 chronic insomnia disorder (disorder-level). OSA was defined according to self-reported frequent obstructive events, snoring or doctor-diagnosed OSA (symptom-level), and doctor-diagnosed OSA (disorder-level). COMISA was defined if both conditions were met (for symptom-level, and disorder-level threshold). Associations with other conditions, and general health were investigated with Poisson regression analyses.ResultsChronic insomnia occurred more frequently among participants with doctor-diagnosed OSA (22.3%), compared to those without (14.3%, p = 0.010). Doctor-diagnosed OSA was more common among participants with chronic insomnia (10.2%) compared to those without (6.2%; p = 0.010). DIMS also occurred more frequently among participants with OSA symptoms (66.6%), compared to those without (47.2%; p < 0.001). Participants with symptom-level COMISA reported increased co-morbid conditions, and worse general health compared to participants with symptoms of insomnia-alone, OSA-alone, or neither insomnia/OSA.ConclusionsCOMISA at symptom and disorder level were common and associated with increased medical and psychiatric co-morbidity, as well as poor general health. More investigation is required to understand bi-directional associations underpinning the high co-morbidity, and improve diagnostic and treatment approaches for COMISA to reduce associated morbidity.     

Delayed reward discounting and increased risk for suicide attempts among U.S. adults with probable PTSD

BackgroundPTSD is an established risk factor for suicide attempts and suicide death, but the mechanisms underlying this association remain unknown. The present study examined associations among delayed reward discounting—the balance between smaller immediate available rewards versus larger delayed rewards—self-reported PTSD symptoms, and recent suicide attempts among individuals reporting suicide ideation within the past year.MethodsA cross-sectional survey of U.S. adults completed the Primary Care PTSD Screen for DSM-5, the 21-item Monetary Choice Questionnaire, and the Self-Injurious Thoughts and Behaviors Interview-Revised. Analyses of variance and multinomial regression models were used to test associations among variables.ResultsAmong participants reporting suicide ideation within the past year, discount rates were significantly higher among those reporting more PTSD symptoms and a past-year suicide attempt, suggesting these participants expressed a preference for immediately available rewards.ConclusionsChoice behavior among individuals reporting many PTSD symptoms and a recent suicide attempt is influenced to a greater degree by immediately available rewards. Sensitivity to immediate rewards at the expense of larger delayed rewards may reflect a vulnerability for suicidal behavior among individuals screening positive for PTSD.     

Investigating the specific domains of the cognitive attentional syndrome that predict posttraumatic stress symptoms: The moderating effect of attentional control

The metacognitive model of posttraumatic stress disorder (PTSD) suggests that persistent use of the maladaptive self-regulation strategies that comprise the cognitive attentional syndrome (CAS) increases the likelihood of developing PTSD symptoms following trauma exposure. The metacognitive model also suggests that flexible regulation of attention might be protective against developing maladaptive outcomes that are associated with the CAS. The aims of this study were to (1) examine associations between all seven domains of the CAS and PTSD symptoms using a recently developed, multidimensional measure of the CAS, and (2) examine the moderating effect of self-reported attentional control on associations between the CAS and PTSD symptoms. Participants were trauma-exposed community adults (N = 237) who completed a battery of self-report measures. Results from linear regression analyses showed that worry, substance use, and internal threat monitoring accounted for unique variance in PTSD symptoms when all seven CAS domains were entered into the same model. Moderation analyses showed that attentional control dampened the effect of the CAS, specifically external threat monitoring, on PTSD symptoms. Study results support attentional control as a protective factor against the maladaptive effects of the CAS on PTSD symptoms.     

Test of the dynamic interplay between DSM-5 PTSD symptom clusters in children and adolescents

BackgroundRevealing the dynamic interplay between posttraumatic stress disorder (PTSD) symptom clusters has always been an important topic in traumatic stress studies. Based on longitudinal studies, different hypotheses have been proposed to explain PTSD symptom dynamics. But currently, no study have been conducted to test these hypotheses in children and adolescents.MethodsData were derived from a longitudinal study of child and adolescent traumatic event survivors of an explosion accident (N = 659). DSM-5 PTSD symptoms was measured by the PTSD Checklist-5 (PCL-5) at 4, 8, and 13 months after the disaster. Latent difference score (LDS) modeling was used to evaluate the dynamic interplay between clusters.ResultsThe results of LDS model indicated that intrusion level positively predicted subsequent rate of increase for hyperarousal (p = .008) and negative changes in cognitions and mood symptoms (p = .036). Also, intrusion level trended to positively predict subsequent increase rate of avoidance symptoms (p = .059).ConclusionsThis study expands previous knowledge of dynamic relations between symptom clusters during the maintenance and fluctuation of child and adolescent PTSD symptoms. By using new methodology, this study provided novel evidence for the hypothesis that intrusion symptom plays an important role in maintaining other PTSD symptoms.     

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.