Testing whether posttraumatic stress disorder and major depressive disorder are similar or unique constructs

PTSD, depression, and treatment outcomes: A latent profile analysis among active duty personnel in a residential PTSD program

Depression frequently co-occurs with posttraumatic stress disorder (PTSD), including among active duty service members. However, symptom heterogeneity of this comorbidity is complex and its association with treatment outcomes is poorly understood, particularly among active duty service members in residential treatment. This study used latent profile analysis (LPA) to identify symptom-based subgroups of PTSD and depression among 282 male service members in a 10-week, residential PTSD treatment program with evidence-based PTSD psychotherapies and adjunctive interventions. The PTSD Checklist-Military Version and Patient Health Questionnaire-8 were completed by service members at pre- and posttreatment and weekly during treatment. Multilevel models compared subgroups on PTSD and depression symptom change across treatment. LPA indicated four subgroups provided optimal fit: Depressive (high depression severity, low PTSD avoidance; n = 33, 11.7%), Avoidant (high PTSD avoidance, moderate depression severity; n = 89, 31.6%), Moderate (moderate PTSD and depression severity; n = 27, 9.6%), and Distressed (high PTSD and depression severity; n = 133, 47.2%). Treatment response differed across classes for both PTSD and depression outcomes (time × LPA class interaction ps < 0.001). In PTSD models, post-hoc comparisons indicated the Moderate class was associated with less PTSD symptom improvement relative to the other classes (ps < 0.006). In depression models, symptom reduction was greatest for the Distressed and Depressive subgroups relative to the other two classes (ps < 0.009). Study results provide an initial model for two prevalent, impairing disorders among service members and show how these symptom-based subgroups may differentially respond to residential PTSD treatment.

Comparing diagnostic criteria for posttraumatic stress disorder in a diverse sample of trauma-exposed youth

Divergent conceptualization of posttraumatic stress disorder (PTSD) within the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5) and International Statistical Classification of Diseases and Related Health Problems (11th ed..; ICD-11) significantly confounds both research and practice. Using a diverse sample of trauma-exposed youth (N = 1,542, age range: 8-20 years), we compared these two diagnostic approaches along with an expanded version of the ICD-11 PTSD criteria that included three additional reexperiencing symptoms (ICD-11+). Within the sample, PTSD was more prevalent using the DSM-5 criteria (25.7%) compared to the ICD-11 criteria (16.0%), with moderate agreement between these diagnostic systems, κ = .57. The inclusion of additional reexperiencing symptoms (i.e., ICD-11+) reduced this discrepancy in prevalence (24.7%) and increased concordance with DSM-5 criteria, κ = .73. All three PTSD classification systems exhibited similar comorbidity rates with major depressive episode (MDE) or generalized anxiety disorder (GAD; 78.0%-83.6%). Most youths who met the DSM-5 PTSD criteria also met the criteria for ICD-11 PTSD, MDE, or GAD (88.4%), and this proportion increased when applying the ICD-11+ criteria (95.5%). Symptom-level analyses identified reexperiencing/intrusions and negative alterations in cognition and mood symptoms as primary sources of discrepancy between the DSM-5 and ICD-11 PTSD diagnostic systems. Overall, these results challenge assertions that nonspecific distress and diagnostically overlapping symptoms within DSM-5 PTSD inflate comorbidity with depressive and anxiety disorders. Further, they support the argument that the DSM-5 PTSD criteria can be refined and simplified without reducing the overall prevalence of psychiatric diagnoses in youth.

Comprehensive bioinformatics analysis of co-expressed genes of post-traumatic stress disorder and major depressive disorder

BACKGROUND

Post-traumatic stress disorder (PTSD) is one of the most serious sequelae of trauma with serious impact worldwide. Studies have suggested an association between PTSD and major depressive disorder (MDD), but the underlying common mechanisms remain unclear. This study aimed to further explore the molecular mechanism between PTSD and MDD via comprehensive bioinformatics analysis.

METHODS

The microarray data of PTSD and MDD were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) analysis and weighted gene co-expression network analysis (WGCNA) were performed to identify the co-expressed genes associated with PTSD and MDD. Gene Set Enrichment Analysis (GSEA), enrichment analyses based on Disease Ontology (DO), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were performed using R software. Then, R software was used for single-sample gene set enrichment analysis (ssGSEA) and immune infiltration analysis on the co-expressed genes in the two datasets., Therefore, a logistic regression model was constructed to predict PTSD and MDD using the R language. Ultimately, this study employed PTSD and MDD models to assess alterations in the expression of target genes within the mouse hippocampus.

RESULTS

Four core genes (GNAQ, DPEP3, ICAM2, PACSIN2) were obtained through different analyses, and these genes had predictive validity for PTSD and MDD, playing an important role in the common mechanism of PTSD and MDD. The study findings reveal decreased expression levels of DPEP3, GNAQ, and PACDIN2 in PTSD samples, accompanied by an increased expression of ICAM2. In MDD samples, the expression of DPEP3 and ICAM2 is reduced, whereas GNAQ and PACDIN2 show an increase in expression.

CONCLUSIONS

This study provides a new perspective on the common molecular mechanisms of PTSD and MDD. These common pathways and core genes may provide promising clues for further experimental studies.

Examining the association between posttraumatic stress disorder and disruptions in cortical networks identified using data-driven methods

Posttraumatic stress disorder (PTSD) is associated with lower cortical thickness (CT) in prefrontal, cingulate, and insular cortices in diverse trauma-affected samples. However, some studies have failed to detect differences between PTSD patients and healthy controls or reported that PTSD is associated with greater CT. Using data-driven dimensionality reduction, we sought to conduct a well-powered study to identify vulnerable networks without regard to neuroanatomic boundaries. Moreover, this approach enabled us to avoid the excessive burden of multiple comparison correction that plagues vertex-wise methods. We derived structural covariance networks (SCNs) by applying non-negative matrix factorization (NMF) to CT data from 961 PTSD patients and 1124 trauma-exposed controls without PTSD. We used regression analyses to investigate associations between CT within SCNs and PTSD diagnosis (with and without accounting for the potential confounding effect of trauma type) and symptom severity in the full sample. We performed additional regression analyses in subsets of the data to examine associations between SCNs and comorbid depression, childhood trauma severity, and alcohol abuse. NMF identified 20 unbiased SCNs, which aligned closely with functionally defined brain networks. PTSD diagnosis was most strongly associated with diminished CT in SCNs that encompassed the bilateral superior frontal cortex, motor cortex, insular cortex, orbitofrontal cortex, medial occipital cortex, anterior cingulate cortex, and posterior cingulate cortex. CT in these networks was significantly negatively correlated with PTSD symptom severity. Collectively, these findings suggest that PTSD diagnosis is associated with widespread reductions in CT, particularly within prefrontal regulatory regions and broader emotion and sensory processing cortical regions.

Association between dimensions of trauma-related psychopathology and asthma in trauma-exposed women

Introduction

Exposure to traumatic events and stressful life experiences are associated with a wide range of adverse mental and physical health outcomes. Studies have found post-traumatic stress disorder (PTSD), depression, and anxiety sensitivity occurrence to be common in addition to inflammatory diseases like asthma, especially in women. Moreover, overlapping neurobiological mechanisms have been linked to both PTSD and asthma.

Methods

In the current study, n = 508 women reported on presence of lifetime asthma diagnosis and symptoms of trauma-related psychopathology including PTSD and depression. A separate group of female participants (n = 64) reported on asthma, PTSD, depression and anxiety sensitivity, and underwent functional MRI scans during a fearful faces task, and their anterior insula responses were analyzed.

Results

Overall, PTSD and depression severity were significantly higher in those with asthma versus those without asthma. There was a positive association between anterior insula response to social threat cues and depression symptoms only among individuals without a lifetime presence of asthma.

Discussion

These findings provide continued evidence on the interactions between stress, neural mechanisms involved in interoception and salience detection, and trauma-related psychopathology.

A Distinction Without a Difference? A Multi-Method Approach to Understanding PTSD and Depression Symptom Overlap Among Disaster-Exposed Adolescents

Among adolescents exposed to trauma, posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) commonly co-occur. Despite the prevalence of comorbidity, the question of how PTSD and MDD are related and appropriate conceptual models for understanding their linkage in adolescence remains unclear. This study applies a multi-methodological approach to advance conceptual and theoretical understanding of the overlap between PTSD and MDD diagnoses/symptoms. We tested three methodological approaches with three distinct theoretical underpinnings on the structure of each disorder proposed in the literature: confirmatory factor analysis (CFA) with dimensional constructs, latent class analysis (LCA) with person-based categorical constructs, and network analysis with symptom-to-symptom associations. Across the three different analytical approaches, there was a significant overlap between PTSD and MDD. Overall, there was no compelling evidence for distinct boundaries between disorders among trauma-exposed adolescents. Instead, we found considerable evidence that the typical latent-construct-based conceptualizations, whether categorical or dimensional, may need revision.

Comorbidity of posttraumatic stress disorder and depression among adolescents following an earthquake: A longitudinal study based on network analysis

BACKGROUND

High comorbidity between posttraumatic stress disorder (PTSD) and depression among adolescents often follows severe traumatic events. Models on the pathway to comorbidity dispute greatly and how PTSD and depression get comorbidity, remain unclear.

METHODS

A follow-up investigation was conducted of 424 adolescent survivors of the Jiuzhaigou earthquake at 12 months (T1) and 27 months (T2).

RESULTS

Contemporaneous network analysis and cross-lagged panel network analysis showed that PTSD and depression are two separate disorders with strong associations via links between dysphoric symptoms of PTSD and somatic or non-somatic symptoms of depression. However, the association weakened from T1 to T2, and internal connections between symptoms within each disorder became stronger.

LIMITATION

We only measured the comorbidity of PTSD and depression at two time points following the earthquake, which may limit the long-term applicability of our findings following trauma.

CONCLUSIONS

The findings also showed that the centrality in contemporaneous networks may indicate node connectivity rather than the influence or potential causality among nodes. These results help to elucidate the relationship between PTSD and depression and could contribute to the development of appropriate therapies.

Symptoms of major depressive disorder and post-traumatic stress disorder in veterans with mild traumatic brain injury: A network analysis

Mild Traumatic Brain Injury (mTBI, or concussion) is a debilitating condition that often leads to persistent cognitive and mental health problems post-injury. Post-traumatic Stress Disorder (PTSD) and Major Depressive Disorder (MDD) are two most commonly occurring mental health problems following mTBI and are suggested to be strong contributors to the persistent post-concussion symptoms. Thus, it is important to understand the symptomatology of PTSD and MDD post-mTBI, to better inform targets for behavioral health interventions. Therefore, the current study examined the symptom structure of post-mTBI co-morbid PTSD and MDD through network approaches; we compared the network structure of participants with a positive mTBI screen (N = 753) to the network structure of participants with a negative mTBI screen (N = 2044); lastly, we examined a network of PTSD and MDD symptoms with clinical covariates in a positive mTBI sample. We found that feeling distant/cutoff (P10) and difficulty concentrating (P15) were the most central symptoms in the positive mTBI network and sleep problems were the most prominent bridge nodes across the disorders. No significant difference between the positive and negative mTBI network were found through network comparison tests. Moreover, anxiety and insomnia were strongly associated with sleep symptoms and irritability symptoms, and emotional support and resilience were potential buffers against most of the PTSD and MDD symptoms. The results of this study might be particularly useful for identifying targets (i.e., feeling distant, concentration and sleep problems) for screening, monitoring and treatment after concussion to better inform post-mTBI mental health care and to improve treatment outcomes.

Objective Cognitive Outcomes and Subjective Emotional Sequelae in Litigating Adults with a Traumatic Brain Injury: The Impact of Performance and Symptom Validity Measures

OBJECTIVE

This study examined the relative contribution of performance and symptom validity in litigating adults with traumatic brain injury (TBI), as a function of TBI severity, and examined the relationship between self-reported emotional symptoms and cognitive tests scores while controlling for validity test performance.

METHOD

Participants underwent neuropsychological assessment between January 2012 and June 2021 in the context of compensation-seeking claims related to a TBI. All participants completed a cognitive test battery, the Personality Assessment Inventory (including symptom validity tests; SVTs), and multiple performance validity tests (PVTs). Data analyses included independent t-tests, one-way ANOVAs, correlation analyses, and hierarchical multiple regression.

RESULTS

A total of 370 participants were included. Atypical PVT and SVT performance were associated with poorer cognitive test performance and higher emotional symptom report, irrespective of TBI severity. PVTs and SVTs had an additive effect on cognitive test performance for uncomplicated mTBI, but less so for more severe TBI. The relationship between emotional symptoms and cognitive test performance diminished substantially when validity test performance was controlled, and validity test performance had a substantially larger impact than emotional symptoms on cognitive test performance.

CONCLUSION

Validity test performance has a significant impact on the neuropsychological profiles of people with TBI, irrespective of TBI severity, and plays a significant role in the relationship between emotional symptoms and cognitive test performance. Adequate validity testing should be incorporated into every neuropsychological assessment, and associations between emotional symptoms and cognitive outcomes that do not consider validity testing should be interpreted with extreme caution.

Enhanced Performance by Interpretable Low-Frequency Electroencephalogram Oscillations in the Machine Learning-Based Diagnosis of Post-traumatic Stress Disorder

Electroencephalography (EEG)-based diagnosis of psychiatric diseases using machine-learning approaches has made possible the objective diagnosis of various psychiatric diseases. The objective of this study was to improve the performance of a resting-state EEG-based computer-aided diagnosis (CAD) system to diagnose post-traumatic stress disorder (PTSD), by optimizing the frequency bands used to extract EEG features. We used eyes-closed resting-state EEG data recorded from 77 PTSD patients and 58 healthy controls (HC). Source-level power spectrum densities (PSDs) of the resting-state EEG data were extracted from 6 frequency bands (delta, theta, alpha, low-beta, high-beta, and gamma), and the PSD features of each frequency band and their combinations were independently used to discriminate PTSD and HC. The classification performance was evaluated using support vector machine with leave-one-out cross validation. The PSD features extracted from slower-frequency bands (delta and theta) showed significantly higher classification performance than those of relatively higher-frequency bands. The best classification performance was achieved when using delta PSD features (86.61%), which was significantly higher than that reported in a recent study by about 13%. The PSD features selected to obtain better classification performances could be explained from a neurophysiological point of view, demonstrating the promising potential to develop a clinically reliable EEG-based CAD system for PTSD diagnosis.

Examining the psychometric properties of the PCL-5 in a black community sample using item response theory

Black Americans are more likely to be exposed to certain types of traumatic events and experience posttraumatic stress disorder (PTSD) compared to other racial groups. Consequently, sound assessment of PTSD in this underserved and understudied population is necessary to develop and accurately answer research questions about etiology and intervention efficacy. However, the item-level psychometric properties of one of the most commonly used assessment tools, the PTSD Checklist for DSM-5 (PCL-5), has yet to be examined among Black Americans. To address this gap, we used item response theory (IRT) to assess item difficulty and discrimination in a sample of Black American adults (n = 307). We employed a graded response model with all 20 items of the PCL-5 loading on to a latent PTSD factor. At clinically significant levels of PTSD, the most discriminating items were flashbacks, inability to experience positive emotions, and nightmares and the least discriminating items were cued emotional distress, diminished interest, and hypervigilance. These results emphasize the importance of flashbacks, inability to experience positive emotions, and nightmares and deemphasize the importance of hypervigilance and sleep difficulties when assessing for clinically significant symptoms of PTSD in Black Americans. Treatment implications include a nuanced approach towards hypervigilance.

Network analysis of comorbid posttraumatic stress disorder and depression in adolescents across COVID-19 epidemic and Typhoon Lekima

BACKGROUND

Network analytic studies indicate that posttraumatic stress disorder (PTSD) may be comorbid with depression at the symptom level, but it remains unclear whether these findings are replicable and generalizable across trauma types.

OBJECTIVE

This study aim was to examine and compare PTSD-depression comorbidity networks of two types of trauma related to Typhoon Lekima and COVID-19 epidemic.

METHODS

Participants were 1605 and 601 adolescents recruited following Typhoon Lekima and the COVID-19 outbreak, respectively.

RESULTS

COVID-19 and Lekima PTSD-depression networks had considerable similarities, including adequate stability and accuracy, connected symptoms of PTSD and depression, symptoms with high centralities, and bridge symptoms. PTSD-depression comorbid symptoms were more complicated in the COVID-19 network but may show more persistence in the Lekima network. Distinct bridge symptoms contributed to the heterogeneity of PTSD-depression comorbidity characteristics between the two networks. Specifically, restricted affect and felt down and unhappy were two important bridge symptoms with high centrality unique to the COVID-19 network.

CONCLUSIONS

PTSD-depression comorbidity network has considerable replicability across trauma types, but specific symptom-level associations and some bridge symptoms may vary across trauma types. These findings also highlight the importance of negative emotions to comorbid PTSD and depression in adolescents following the COVID-19 outbreak compared with Typhoon Lekima.

The symptom structure of posttraumatic stress disorder and co-morbid depression among college students with childhood abuse experience: A network analysis

BACKGROUND

Posttraumatic stress disorder (PTSD) and depression are highly co-morbid among individuals with childhood abuse history, while the mechanism of the co-morbidity is highly debated. This study sought to extent the work among college students with network analysis, which is a novel method that sees the co-morbidity from a symptom interacting perspective.

METHODS

Data was collected from 476 college students who were assessed to have childhood abuse history, PTSD and depression at the same time, using Childhood Trauma Questionnaire- Short Form, PTSD Checklist for DSM-5 and The Center for Epidemiological Studies Depression. We created a Graphical Gaussian Model (GGM) network to show associations between symptom pairs and a Directed Acyclic Graph (DAG) to estimate potential casual relationships among symptoms.

RESULTS

The GGM network was reliably stable, feeling sad (Depression) and trouble experiencing positive feelings (PTSD) were the most central nodes. Trouble experiencing positive feelings and several negative affect symptoms, sleep problems and difficulty in concentrating were acting as important bridging nodes. The DAG network suggested the key triggering roles of exaggerated startle (PTSD) and several re-experiencing symptoms.

LIMITATIONS

The study used cross-sectional data and self-reported measures. Results from network analysis could be affected by scale factors and contain spurious correlations.

CONCLUSIONS

In the childhood-abuse-related co-morbid structure, several negative affect symptoms both in PTSD and depression have pivotal roles, hyper-arousal symptoms and re-experiencing symptoms could trigger the co-morbid structure. Illustrating the strength and limitations of network analysis, this study help target the potentially influential symptoms for better clinical intervention.

Psychological trauma and the genetic overlap between posttraumatic stress disorder and major depressive disorder

BACKGROUND

Posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) are commonly reported co-occurring mental health consequences of psychological trauma exposure. The disorders have high genetic overlap. Trauma is a complex phenotype but research suggests that trauma sensitivity has a heritable basis. We investigated whether sensitivity to trauma in those with MDD reflects a similar genetic component in those with PTSD.

METHODS

Genetic correlations between PTSD and MDD in individuals reporting trauma and MDD in individuals not reporting trauma were estimated, as well as with recurrent MDD and single-episode MDD, using genome-wide association study (GWAS) summary statistics. Genetic correlations were replicated using PTSD data from the Psychiatric Genomics Consortium and the Million Veteran Program. Polygenic risk scores were generated in UK Biobank participants who met the criteria for lifetime MDD (N = 29 471). We investigated whether genetic loading for PTSD was associated with reporting trauma in these individuals.

RESULTS

Genetic loading for PTSD was significantly associated with reporting trauma in individuals with MDD [OR 1.04 (95% CI 1.01-1.07), Empirical-p = 0.02]. PTSD was significantly more genetically correlated with recurrent MDD than with MDD in individuals not reporting trauma (rg differences = ~0.2, p < 0.008). Participants who had experienced recurrent MDD reported significantly higher rates of trauma than participants who had experienced single-episode MDD (χ2 > 166, p < 0.001).

CONCLUSIONS

Our findings point towards the existence of genetic variants associated with trauma sensitivity that might be shared between PTSD and MDD, although replication with better powered GWAS is needed. Our findings corroborate previous research highlighting trauma exposure as a key risk factor for recurrent MDD.

Posttraumatic stress disorder (PTSD) and depression severity in sexually assaulted women: hypothalamic-pituitary-adrenal (HPA) axis alterations

BACKGROUND

Sexual assault is implicated in several adverse psychological and physical health outcomes, including posttraumatic stress disorder (PTSD) and depression. Neurobiological research has shown variations related to the hypothalamic-pituitary-adrenal (HPA) axis, immune alterations, metabolic function, and brain circuitry. Although these mechanisms have been extensively studied, the results have demonstrated different outcomes in PTSD.

METHODS

We compared the plasma adrenocorticotropin (ACTH) and salivary cortisol levels of fifty-eight women with PTSD developed after sexual assault to those of forty-four female controls with no history of trauma. We also evaluated the psychiatric diagnosis and symptom severity of PTSD and depression. The participants' clinical conditions were associated with their hormonal levels to assess whether symptom severity was related to hormonal imbalance.

RESULTS

A large percentage of sexually assaulted women had PTSD and comorbid depression. The ACTH levels were higher in the PTSD group than the control group and increased as PTSD severity increased, considering depressive symptoms, measured by the Beck Depression Inventory (BDI) (p < 0.0001), as well as PTSD symptoms, measured by subscale D of the Clinician-Administered PTSD Scale (CAPS-5) (p = 0.045) and the CAPS-5 total scale (p = 0.026). Cortisol levels measured at 10 pm were higher for the PTSD group than the control group (p = 0.045, p = 0.037, respectively), and the cortisol awakening response showed elevated cortisol levels for the PTSD group.

CONCLUSIONS

These results show a correlation between symptom severity and HPA axis imbalance in patients with PTSD. Elevated ACTH and an elevated cortisol response in patients with comorbid depressive symptoms were the opposite of the expected response for patients with PTSD only. This association leads to the hypothesis that the neurobiological alterations of PTSD are related to the type of symptoms presented and their severity. These manifestations likely influence the disease course, prognosis and response to treatment. These outcomes highlight the need to discuss particular neurobiological alterations in patients with PTSD developed after sexual assault, mainly those with severe depressive symptoms.

Post-Traumatic Stress Disorder Symptoms Contribute to Worse Pain and Health Outcomes in Veterans With PTSD Compared to Those Without: A Systematic Review With Meta-Analysis

INTRODUCTION

Post-traumatic stress disorder (PTSD) and chronic pain are frequently co-morbid conditions in the U.S. veteran population. Although several theories about the cause of increased pain prevalence in individuals with PTSD have been presented, no synthesis of primary data informing the impact of co-morbid PTSD and pain has been completed. The purpose of this study was to systematically review the literature and quantify disability, function, and pain-related beliefs and outcomes in veterans with PTSD compared to veterans without PTSD.

MATERIALS AND METHODS

A systematic search of three electronic databases was conducted. Inclusion criteria required pain-related comparison of veterans with PTSD to those without PTSD. Primary outcome measures and standardized mean differences (SMDs) were assessed for pain, function, disability, pain beliefs, and healthcare utilization using a random effects model.

RESULTS

20 original research studies met inclusion criteria and were assessed for quality and outcomes of interest. The majority of studies were cross-sectional. Veterans with PTSD and pain demonstrated higher pain (SMD = 0.58, 95% CI 0.28-0.89), disability (SMD = 0.52, 95%CI 0.33-0.71), depression (SMD = 1.40, 95%CI 1.2-1.6), catastrophizing beliefs (SMD = 0.95, 95% CI 0.69-1.2), sleep disturbance (SMD = 0.80, 95% CI 0.57-1.02), and healthcare utilization; they had lower function (SMD = 0.41, 95% CI 0.25-0.56) and pain self-efficacy (SMD = 0.77, 95% CI 0.55-0.99) compared to veterans without PTSD.

CONCLUSION

In veterans with chronic pain, PTSD symptomology has a large effect for many negative health-related outcomes. This review supports the need for clinicians to screen and understand the effects of PTSD symptoms on patients with pain. Clinicians should recognize that veterans with PTSD and pain likely have elevated pain catastrophizing beliefs and decreased self-efficacy that should be targeted for intervention.

Symptom structure of PTSD and co-morbid depressive symptoms - a network analysis of combat veteran patients

BACKGROUND

Despite extensive research, symptom structure of posttraumatic stress disorder (PTSD) is highly debated. The network approach to psychopathology offers a novel method for understanding and conceptualizing PTSD. However, extant studies have mainly used small samples and self-report measures among sub-clinical populations, while also overlooking co-morbid depressive symptoms.

METHODS

PTSD symptom network topology was estimated in a sample of 1489 treatment-seeking veteran patients based on a clinician-rated PTSD measure. Next, clinician-rated depressive symptoms were incorporated into the network to assess their influence on PTSD network structure. The PTSD-symptom network was then contrasted with the network of 306 trauma-exposed (TE) treatment-seeking patients not meeting full criteria for PTSD to assess corresponding network differences. Finally, a directed acyclic graph (DAG) was computed to estimate potential directionality among symptoms, including depressive symptoms and daily functioning.

RESULTS

The PTSD symptom network evidenced robust reliability. Flashbacks and getting emotionally upset by trauma reminders emerged as the most central nodes in the PTSD network, regardless of the inclusion of depressive symptoms. Distinct clustering emerged for PTSD and depressive symptoms within the comorbidity network. DAG analysis suggested a key triggering role for re-experiencing symptoms. Network topology in the PTSD sample was significantly distinct from that of the TE sample.

CONCLUSIONS

Flashbacks and psychological reactions to trauma reminders, along with their strong connections to other re-experiencing symptoms, have a pivotal role in the clinical presentation of combat-related PTSD among veterans. Depressive and posttraumatic symptoms constitute two separate diagnostic entities, but with meaningful between-disorder connections, suggesting two mutually-influential systems.

Beyond postpartum depression: posttraumatic stress-depressive response following childbirth

Although depression following childbirth is well recognized, much less is known about comorbid postpartum psychiatric conditions. Some women can endorse posttraumatic stress related to the childbirth experience accompanied by symptoms of depression. The objective of our study was to examine the nature of the comorbidity of symptoms of childbirth-related posttraumatic stress disorder (PTSD) and postpartum depression. We studied a sample of 685 women who were on average 3 months following childbirth and collected data about their mental health pertaining to PTSD, depression, general distress, and childbirth experience. The vast majority of women with elevated childbirth-related PTSD symptoms also endorsed elevated postpartum depression symptoms. Factor analysis revealed that symptoms of childbirth-related PTSD and postpartum depression loaded onto one single factor rather than two factors. Stepwise multi-nominal regression analysis revealed that childbirth stressors, including obstetric complications and peritraumatic distress in birth, predicted the likelihood of developing comorbid childbirth-related PTSD and postpartum depression, but not depression alone. The findings suggest that beyond postpartum depression, postpartum women suffer from a posttraumatic stress-depressive response in the wake of a traumatic childbirth experience. Increasing awareness in routine postpartum care about traumatic childbirth and its associated emotional sequela is warranted.

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.

Combining Text Mining of Long Constructed Responses and Item-Based Measures: A Hybrid Test Design to Screen for Posttraumatic Stress Disorder (PTSD)

This article introduces a new hybrid intake procedure developed for posttraumatic stress disorder (PTSD) screening, which combines an automated textual assessment of respondents’ self-narratives and item-based measures that are administered consequently. Text mining technique and item response modeling were used to analyze long constructed response (i.e., self-narratives) and responses to standardized questionnaires (i.e., multiple choices), respectively. The whole procedure is combined in a Bayesian framework where the textual assessment functions as prior information for the estimation of the PTSD latent trait. The purpose of this study is twofold: first, to investigate whether the combination model of textual analysis and item-based scaling could enhance the classification accuracy of PTSD, and second, to examine whether the standard error of estimates could be reduced through the use of the narrative as a sort of routing test. With the sample at hand, the combination model resulted in a reduction in the misclassification rate, as well as a decrease of standard error of latent trait estimation. These findings highlight the benefits of combining textual assessment and item-based measures in a psychiatric screening process. We conclude that the hybrid test design is a promising approach to increase test efficiency and is expected to be applicable in a broader scope of educational and psychological measurement in the future.

Machine-learning-based classification between post-traumatic stress disorder and major depressive disorder using P300 features

BACKGROUND

The development of optimal classification criteria for specific mental disorders which share similar symptoms is an important issue for precise diagnosis. We investigated whether P300 features in both sensor-level and source-level could be effectively used to classify post-traumatic stress disorder (PTSD) and major depressive disorder (MDD).

METHOD

EEG signals were recorded from fifty-one PTSD patients, 67 MDD patients, and 39 healthy controls (HCs) while performing an auditory oddball task. Amplitude and latency of P300 were evaluated, and the current source analysis of P300 components was conducted using sLORETA. Finally, we classified two groups using machine-learning methods with both sensor- and source-level features. Moreover, we checked the comorbidity effects using the same approaches (PTSD-mono diagnosis (PTSDm, n = 28) and PTSD-comorbid diagnosis (PTSDc, n = 23)).

RESULTS

PTSD showed significantly reduced P300 amplitudes and prolonged latency compared to HCs and MDD. Moreover, PTSD showed significantly reduced source activities, and the source activities were significantly correlated with symptoms of depression and anxiety. Also, the best classification accuracy at each pair was as follows: 80.00% (PTSD-HCs), 67.92% (MDD-HCs), 70.34% (PTSD-MDD), 82.09% (PTSDm-HCs), 71.58% (PTSDm-MDD), 82.56% (PTSDc-HCs), and 76.67% (PTSDc- MDD).

CONCLUSION

Since abnormal P300 reflects pathophysiological characteristics of PTSD, PTSD patients were well-discriminated from MDD and HCs when using P300 features. Thus, altered P300 characteristics in both sensor- and source-level may be useful biomarkers to diagnosis PTSD.

Post-traumatic stress and major depressive disorders in parent caregivers of children with a chronic disorder

Post-traumatic Stress Disorder (PTSD) and Major Depressive Disorder (MDD) are the most common psychiatric consequences among caregivers of pediatric patients affected by severe chronic illnesses. The aims of this study were to describe rates of PTSD and MDD in a sample of parents of epileptic children, and to examine the correlations between symptoms of post-traumatic stress and depression. Parents of children with epilepsy were enrolled and screened by means of the PTSD module of the Semi-Structured Clinical Interview for DSM-5 (SCID-5) and of the Hamilton Rating Scale for depression (HAM-D). They also completed the Trauma and Loss Spectrum Self-Report (TALS-SR), an international instrument to evaluate post-traumatic stress spectrum symptoms. Results revealed PTSD rates of 15.7% (19.5% mothers, 8,1% fathers; p = .043) and MDD rates of 7.5% (10.2% mothers,1.8% fathers; p = .064). A model of multiple linear regression indicated a significant B linear regression coefficient between being mothers (p = .012), witnessing tonic-clonic seizures (p = .015) and having higher TALS-SR total score (p < .001) as predictors of HAM-D total score. Our findings highlight the relationship between PTSD and MDD, evidencing the need for further studies on pediatric caregivers aimed to develop specific intervention programs of healthcare prevention and assistance.

Psychological Inflexibility Predicts of Suicidal Ideation Over Time in Veterans of the Conflicts in Iraq and Afghanistan

Psychological inflexibility, or how individuals respond to distressing internal experiences, may be a modifiable risk factor for suicide in veterans. It was hypothesized that psychological inflexibility would predict suicidal ideation after accounting for established risk factors at baseline and 1 year later. Post-9/11 veterans (N = 309) completed clinical interview and self-report measures at baseline and 1-year follow-up. Results indicated that psychological inflexibility predicted severity of suicidal ideation at both baseline and 1 year later, after accounting for established risk factors. Psychological inflexibility is an important marker of risk for suicidal ideation, and could be a target for interventions aimed at reducing suicide.

Factors mediating the impacts of child abuse and intimate partner violence on chronic pain: a cross-sectional study

BACKGROUND

Most research on the health impacts of intimate partner violence (IPV) and child abuse has been conducted in Western countries and may not be generalizable to women living in different contexts, such as Saudi Arabia. Chronic pain, a disabling health issue associated with experiences of both child abuse and IPV among women, negatively impacts women's well-being, quality of life, and level of functioning. Yet, the psychosocial mechanisms that explain how abuse relates to chronic pain are poorly understood. We developed and tested a theoretical model that explains how both IPV and child abuse are related to chronic pain.

METHODS

We recruited a convenience sample of 299 Saudi women, who had experienced IPV in the past 12 months, from nine primary health care centers in Saudi Arabia between June and August 2015. Women completed a structured interview comprised of self-report measures of IPV, child abuse, PTSD, depressive symptoms, chronic pain, and social support. Using Structural equation modeling (SEM), we analyzed the proposed model twice with different mental health indicators as mediators: PTSD symptoms (Model 1) and depressive symptoms (Model 2).

RESULTS

Both models were found to fit the data, accounting for 31.6% (Model 1) and 32.4% (Model 2) of the variance in chronic pain severity. In both models, mental health problems (PTSD and depressive symptoms) fully mediated the relationship between severity of IPV and child abuse and chronic pain severity. Perceived family support partially mediated the relationship between abuse severity and depressive symptoms.

CONCLUSIONS

These results underscore the significance of considering lifetime abuse, women's mental health (depressive and PTSD symptoms) and their social resources in chronic pain management and treatment.

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.

Comorbid mood and anxiety disorders and severity of posttraumatic stress disorder symptoms in treatment-seeking veterans

OBJECTIVE

Comorbidity is the rule and not the exception among veterans with posttraumatic stress disorder (PTSD). Examining comorbidities in a veteran population allows us to better understand veterans' symptoms and recognize when mental health treatment may need to be tailored to other co-occurring issues. This article evaluates comorbid mood and anxiety disorders and PTSD symptom severity in a large sample of veterans from multiple eras of service, including the recent wars in Iraq and Afghanistan.

METHOD

The current study used data from veterans who sought treatment for PTSD at a VA PTSD Clinical Team from 2005 to 2013. Veterans were assessed for PTSD, mood, and anxiety disorders using a structured clinical interview and completed self-report symptom measures as part of the PTSD clinic intake procedure. A total of 2,460 veterans were evaluated, and 867 met diagnostic criteria for PTSD.

RESULTS

Veterans with PTSD were significantly more likely than those without PTSD to be diagnosed with social anxiety disorder and obsessive-compulsive disorder, but significantly less likely to be diagnosed with depression. In addition, veterans who had at least one comorbid diagnosis in addition to PTSD reported significantly higher PTSD symptom severity than veterans with PTSD alone. PTSD symptom severity also varied by era of service.

CONCLUSION

These results suggest that among veterans seeking treatment for PTSD, comorbid mood and anxiety disorders may be associated with greater severity of PTSD symptoms. Future work is needed to determine the impact of specific comorbidities on trauma-focused treatment outcomes. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Heterogeneity in the Strength of the Relation Between Social Support and Post-Trauma Psychopathology

Potentially traumatic events (PTEs) increase risk for psychopathology, including posttraumatic stress disorder (PTSD), major depressive disorder (MDD), and generalized anxiety disorder (GAD). Social support (SS) is associated with reduced symptoms for each disorder. Each disorder, however, is highly heterogeneous such that they are comprised of clusters of different symptoms. It is unclear if SS is associated with all clusters equally. The current study examined the relation between SS and the symptom clusters of each disorder. Participants completed a battery of self-report assessments for PTSD, MDD, GAD, and SS. All participants experienced a Criterion A traumatic event. Although SS was significantly associated with all symptom clusters, the strength of relations varied. The relation between SS and MDD-affective was significantly stronger than its association with all other factors. The relations between SS and GAD, MDD-somatic, PTSD-AAR, and PTSD-NACM did not significantly differ. These relations were stronger than the relations between SS and the remaining PTSD factors. There was no significant difference in the relations between SS and PTSD-intrusions or PTSD-avoidance. These results suggest that SS is more closely aligned to specific aspects of post-trauma psychopathology.

Interpersonal trauma and hoarding: The mediating role of aggression

BACKGROUND

A growing body of literature indicates that exposure to interpersonal trauma contributes to the onset or exacerbation of hoarding symptoms. However, little research has explored psychosocial factors that may help to explain the relationship between interpersonal trauma and hoarding symptoms. One outcome of trauma exposure that may be associated with hoarding symptoms is aggression, defined as the tendency to experience and express hostility and anger, and to engage in aggressive behavior. Therefore, the current study examined the relationship between hoarding and aggression, as well as the mediating role of aggression in the relationship between exposure to interpersonal trauma and hoarding symptoms.

METHODS

Community participants (n = 258) completed a battery of questionnaires assessing trauma exposure, hoarding symptoms, aggression, and negative affect.

RESULTS

Results revealed that when accounting for negative affect, hoarding symptoms were associated with greater aggression, and the relationship between exposure to interpersonal trauma and hoarding symptoms was mediated by aggression. Specificity analyses indicated that depression symptoms and emotion dysregulation did not mediate the relationship between interpersonal trauma exposure and hoarding, providing further support for the importance of aggression.

LIMITATIONS

Findings should be interpreted in light of limitations, including the use of cross-sectional and self-report data, and a general community sample.

CONCLUSIONS

Taken together, our findings suggest that interpersonal processes, such as aggression toward others, may be associated with increased hoarding symptoms.

The structure of co-occurring PTSD and depression symptoms in a cohort of Marines pre- and post-deployment

Symptoms of posttraumatic stress disorder (PTSD) and major depressive disorder are the most frequently co-occurring problems following potentially traumatic events. It is unclear whether these comorbidities represent two correlated but distinct disorders or a common post-event response. We sought to inform this question by examining the distinctiveness of PTSD and depression symptoms at four cross-sectional time points, using data from a parent prospective longitudinal study of 858 Marines evaluated before deployment and approximately 1, 5, and 8 months after returning from the Afghanistan war. We conducted a series of cross-sectional confirmatory factor analyses of PTSD and depression symptoms at each time point, using the Posttraumatic Stress Disorder Checklist IV and the Beck Depression Inventory II. Analyses indicated that across all four assessments, self-reported symptoms on the measures were best explained by distinct but correlated subclusters of symptoms within each measure. This structure was supported by the data both before and after deployment, even with increases in average PTSD symptoms after deployment. These findings suggest that despite shared method variance and some symptom overlap, self-reports of PTSD and depression symptoms across a stressful combat deployment show distinct symptom subclusters rather than a general common trauma reaction in this sample of Marines.

Applying network analysis to psychological comorbidity and health behavior: Depression, PTSD, and sexual risk in sexual minority men with trauma histories

OBJECTIVE

High rates of depression and posttraumatic stress disorder (PTSD) contribute to sexual risk, particularly in men who have sex with men (MSM) who have experienced childhood sexual abuse. The comorbidity between depression and PTSD and mechanisms by which they contribute to sexual risk in MSM remain unclear. This study sought to demonstrate the feasibility and utility of a network approach to (a) characterize symptom interconnections between depression and PTSD in MSM, (b) identify specific symptoms related to sexual risk behavior, and (c) compare symptom networks across groups at different levels of risk.

METHOD

Cross-sectional baseline data were collected from 296 HIV-negative urban MSM as part of a multisite randomized intervention trial. Symptoms of depression and PTSD were self-reported along with sexual risk behavior. Analyses were performed in R using regularized partial correlation network modeling.

RESULTS

Network analyses revealed complex associations between depression and PTSD symptoms and in relation to sexual risk behavior. While symptoms clustered within their respective disorders, depression and PTSD were connected at key symptom nodes (e.g., sleep, concentration). Specific symptoms (e.g., avoiding thoughts and feelings) were linked to sexual risk behavior. Network comparisons across risk groups suggested avoidant processes could be more readily activated in higher-risk individuals, whereas hyperarousal symptoms may be more salient and protective for lower-risk individuals.

CONCLUSIONS

This study is one of the earliest network analyses of depression and PTSD, and first to extend this inquiry to health behavior. Symptom-level investigations may clarify mechanisms underlying psychological comorbidity and behavioral risk in MSM and refine targets for intervention/prevention. (PsycINFO Database Record

Genome-wide association study of subcortical brain volume in PTSD cases and trauma-exposed controls

Depending on the traumatic event, a significant fraction of trauma survivors subsequently develop PTSD. The additional variability in PTSD risk is expected to arise from genetic susceptibility. Unfortunately, several genome-wide association studies (GWAS) have failed to identify a consistent genetic marker for PTSD. The heritability of intermediate phenotypes such as regional brain volumes is often 80% or higher. We conducted a GWAS of subcortical brain volumes in a sample of recent military veteran trauma survivors (n = 157), grouped into PTSD (n = 66) and non-PTSD controls (n = 91). Covariates included PTSD diagnosis, sex, intracranial volume, ancestry, childhood trauma, SNP×PTSD diagnosis, and SNP×childhood trauma. We identified several genetic markers in high linkage disequilibrium (LD) with rs9373240 (p = 2.0 × 10^-7, FDR q = 0.0375) that were associated with caudate volume. We also observed a significant interaction between rs9373240 and childhood trauma (p-values = 0.0007-0.002), whereby increased trauma exposure produced a stronger association between SNPs and increased caudate volume. We identified several SNPs in high LD with rs34043524, which is downstream of the TRAM1L1 gene that were associated with right lateral ventricular volume (p = 1.73 × 10^-7; FDR q = 0.032) and were also associated with lifetime alcohol abuse or dependence (p = 2.49 × 10^-7; FDR q = 0.0375). Finally, we identified several SNPs in high LD with rs13140180 (p = 2.58 × 10^-7; FDR q = .0016), an intergenic region on chromosome 4, and several SNPs in the TMPRSS15 associated with right nucleus accumbens volume (p = 2.58 × 10^-7; FDR q = 0.017). Both TRAM1L1 and TMPRSS15 have been previously implicated in neuronal function. Key results survived genome-wide multiple-testing correction in our sample. Leveraging neuroimaging phenotypes may offer a shortcut, relative to clinical phenotypes, in mapping the genetic architecture and neurobiological pathways of PTSD.

Trauma characteristics, post-traumatic symptoms, psychiatric disorders and suicidal behaviours: Results from the 2007 Australian National Survey of Mental Health and Wellbeing

OBJECTIVE

The current study examined whether trauma characteristics such as the type and number of traumatic events were associated with three suicidal behaviours (i.e. ideation, plan and attempt) after adjusting for sociodemographic factors, post-traumatic symptoms and history of psychiatric disorders.

METHOD

Data came from the 2007 Australian National Survey of Mental Health and Wellbeing ( N = 8841). Respondents were asked about exposure to 28 traumatic events that occurred during their lifetime. Suicidal behaviours were measured using three statements about whether the person ever seriously thought about or planned or attempted suicide.

RESULTS

Sexual violence and exposure to multiple traumatic events were particularly associated with suicidal behaviours. The presence of the emotional numbing symptom cluster and co-occurrence of three psychiatric disorders (major depressive disorder, alcohol use disorder and substance use disorder) also increased the odds of suicidal behaviours. Analysis of age of onset revealed that the mean age of traumatic exposure was earlier than the age at which suicidal behaviours emerged.

CONCLUSIONS

The current study is the first to demonstrate that sexual violence and exposure to multiple traumatic events are associated with suicidal behaviours in a representative sample of Australian adults. The results underline the potential benefits of thorough assessment of trauma history, post-traumatic symptoms and history of psychiatric disorders and their additive contribution in suicide risk among trauma victims. These findings can be used by clinicians and researchers for early intervention programmes.

Neurodegenerative and psychiatric diseases among families with amyotrophic lateral sclerosis

OBJECTIVE

To estimate risks of neurodegenerative and psychiatric diseases among patients with amyotrophic lateral sclerosis (ALS) and their families.

METHODS

We conducted a register-based nested case-control study during 1990-2013 in Sweden to assess whether patients with ALS had higher risks of other neurodegenerative and psychiatric diseases before diagnosis. We included 3,648 patients with ALS and 36,480 age-, sex-, and county of birth-matched population controls. We further conducted a follow-up study of the cases and controls to assess the risks of other neurodegenerative and psychiatric diseases after ALS diagnosis. To assess the potential contribution of familial factors, we conducted similar studies for the relatives of patients with ALS and their controls.

RESULTS

Individuals with previous neurodegenerative or psychiatric diseases had a 49% increased risk of ALS (odds ratio 1.49, 95% confidence interval 1.35-1.66) compared to individuals without these diseases. After diagnosis, patients with ALS had increased risks of other neurodegenerative or psychiatric diseases (hazard ratio 2.90, 95% confidence interval 2.46-3.43) compared to individuals without ALS. The strongest associations were noted for frontotemporal dementia, Parkinson disease, other dementia, Alzheimer disease, neurotic disorders, depression, stress-related disorders, and drug abuse/dependence. First-degree relatives of patients with ALS had higher risk of neurodegenerative diseases, whereas only children of patients with ALS had higher risk of psychiatric disorders, compared to relatives of the controls.

CONCLUSIONS

Familial aggregation of ALS and other neurodegenerative diseases implies a shared etiopathogenesis among all neurodegenerative diseases. The increased risk of psychiatric disorders among patients with ALS and their children might be attributable to nonmotor symptoms of ALS and severe stress response toward the diagnosis.

Exploring a post-traumatic stress disorder paradigm in Flinders sensitive line rats to model treatment-resistant depression II: response to antidepressant augmentation strategies

OBJECTIVE

Post-traumatic stress disorder (PTSD) displays high co-morbidity with major depression and treatment-resistant depression (TRD). Earlier work demonstrated exaggerated depressive-like symptoms in a gene×environment model of TRD and an abrogated response to imipramine. We extended the investigation by studying the behavioural and monoaminergic response to multiple antidepressants, viz. venlafaxine and ketamine with/without imipramine.

METHODS

Male Flinders sensitive line (FSL) rats, a genetic model of depression, were exposed to a time-dependent sensitisation (TDS) model of PTSD and compared with stress naive controls. 7 days after the TDS procedures, immobility and coping (swimming and climbing), behaviours in the forced swim test (FST) as well as hippocampal and cortical 5-hydroxyindoleacetic acid (5HIAA) and noradrenaline (NA) levels were analysed. Response to imipramine, venlafaxine and ketamine treatment (all 10 mg/kg×7 days) alone and in combination were subsequently studied.

RESULTS

TDS exacerbated depressive-like behaviour of FSL rats in the FST. Imipramine, venlafaxine and ketamine were ineffective as monotherapy in TDS-exposed FSL rats. However, combining imipramine with either venlafaxine or ketamine resulted in significant anti-immobility effects and enhanced coping behaviours. Only ketamine+imipramine (frontal-cortical 5HIAA and NA), ketamine alone (frontal-cortical and hippocampal NA) and venlafaxine+imipramine (frontal-cortical NA) altered monoamine responses versus untreated TDS-exposed FSL rats.

CONCLUSION

Exposure of FSL rats to TDS inhibits antidepressant response at behavioural and neurochemical levels. Congruent with TRD, imipramine plus venlafaxine or ketamine overcame treatment resistance in these animals. These data further support the hypothesis that exposure of FSL rats to a PTSD-like paradigm produces a valid animal model of TRD and warrants further investigation.

Exploring a post-traumatic stress disorder paradigm in Flinders sensitive line rats to model treatment-resistant depression I: bio-behavioural validation and response to imipramine

OBJECTIVE

Co-morbid depression with post-traumatic stress disorder (PTSD) is often treatment resistant. In developing a preclinical model of treatment-resistant depression (TRD), we combined animal models of depression and PTSD to produce an animal with more severe as well as treatment-resistant depressive-like behaviours.

METHODS

Male Flinders sensitive line (FSL) rats, a genetic animal model of depression, were exposed to a stress re-stress model of PTSD [time-dependent sensitisation (TDS)] and compared with stress-naive controls. Seven days after TDS stress, depressive-like and coping behaviours as well as hippocampal and cortical noradrenaline (NA) and 5-hydroxyindoleacetic acid (5HIAA) levels were analysed. Response to sub-chronic imipramine treatment (IMI; 10 mg/kg s.c.×7 days) was subsequently studied.

RESULTS

FSL rats demonstrated bio-behavioural characteristics of depression. Exposure to TDS stress in FSL rats correlated negatively with weight gain, while demonstrating reduced swimming behaviour and increased immobility versus unstressed FSL rats. IMI significantly reversed depressive-like (immobility) behaviour and enhanced active coping behaviour (swimming and climbing) in FSL rats. The latter was significantly attenuated in FSL rats exposed to TDS versus unstressed FSL rats. IMI reversed reduced 5HIAA levels in unstressed FSL rats, whereas exposure to TDS negated this effect. Lowered NA levels in FSL rats were sustained after TDS with IMI significantly reversing this in the hippocampus.

CONCLUSION

Combining a gene-X-environment model of depression with a PTSD paradigm produces exaggerated depressive-like symptoms that display an attenuated response to antidepressant treatment. This work confirms combining FSL rats with TDS exposure as a putative animal model of TRD.

Network approach to the symptom-level association between alcohol use disorder and posttraumatic stress disorder

PURPOSE

The high prevalence of alcohol use disorder among individuals with a history of trauma and posttraumatic stress disorder is well documented. The current study applied network analysis to map the structure of symptom associations between these disorders.

METHODS

Data come from a community sample of 449 Australian adults with a history of trauma and alcohol consumption during the last 12 months. Data analysis consisted of the construction of the comorbidity network of PTSD/AUD symptoms, identification of the bridging symptoms, computation of the centrality measures, and evaluation of the robustness of the results.

RESULTS

Results highlighted two main symptom clusters, corresponding to two disorders, and that only nine edges connected the two clusters. Bridging symptoms connecting the two clusters were: alcohol use in dangerous situations, physical or mental health problems as a result of alcohol use, loss of interest or reduced social activities, and reckless/self-destructive behaviour.

CONCLUSIONS

Identification of both central symptoms, because of their key role in the constellation and strong associations with majority of symptoms, and bridge symptoms, because of their mediating role between two disorders, has some implications in terms of self-medication and risk-taking/self-regulation theories of comorbidity and provides a number of clinical implications, which warrants further exploration within clinical samples.

A network approach to the comorbidity between posttraumatic stress disorder and major depressive disorder: The role of overlapping symptoms

BACKGROUND

The role of symptom overlap between major depressive disorder and posttraumatic stress disorder in comorbidity between two disorders is unclear. The current study applied network analysis to map the structure of symptom associations between these disorders.

METHODS

Data comes from a sample of 909 Australian adults with a lifetime history of trauma and depressive symptoms. Data analysis consisted of the construction of two comorbidity networks of PTSD/MDD with and without overlapping symptoms, identification of the bridging symptoms, and computation of the centrality measures.

RESULTS

The prominent bridging role of four overlapping symptoms (i.e., sleep problems, irritability, concentration problems, and loss of interest) and five non-overlapping symptoms (i.e., feeling sad, feelings of guilt, psychomotor retardation, foreshortened future, and experiencing flashbacks) is highlighted.

LIMITATIONS

The current study uses DSM-IV criteria for PTSD and does not take into consideration significant changes made to PTSD criteria in DSM-5. Moreover, due to cross-sectional nature of the data, network estimates do not provide information on whether a symptom actively triggers other symptoms or whether a symptom mostly is triggered by other symptoms.

CONCLUSION

The results support the role of dysphoria-related symptoms in PTSD/MDD comorbidity. Moreover, Identification of central symptoms and bridge symptoms will provide useful targets for interventions that seek to intervene early in the development of comorbidity.

Assessment of depression in veterans across missions: a validity study using Rasch measurement models

Background: Depression is a common psychopathological outcome following military deployment. Previous studies have reported differing rates of post-deployment depression, indicating that the toll of war differs across missions. However, it is unclear to what degree the varying prevalence is due methodological differences. Studies comparing rates of depression across cohorts using the same methodology and ensuring measurement invariance are rare, leaving us with limited knowledge on the actual depression prevalence variance across missions. Objective: Applying Rasch models (RM), we aim to validate a measure of depression distributed to all personnel deployed with the Danish Defense since 1998. The main focus was establishing a sufficient sum score and measurement invariance relative to deployment cohort. Method: Two cohorts of the International Security Assistance Force (ISAF) deployed to Afghanistan in 2009 (ISAF7, N = 265) and 2013 (ISAF15, N = 271) were included. Participants filled out a questionnaire concerning their Psychological Reactions to International Missions (PRIM) approximately seven months after home-coming. The questionnaire included a 10-item scale of depression symptoms (PRIM-Depression). The validity of the PRIM-Depression was tested using RM with specific focus on differential item functioning (DIF) across the two cohorts. Results: The PRIM-Depression scale displayed excellent overall consistency and showed no problems with monotonicity or homogeneity. However, the full PRIM-Depression scale did not fit a pure RM. We therefore tested the fit of items to a graphical log-linear RM and found evidence of DIF for two items relative to cohort. We proceeded without these two items and tested the resulting 8-item version which fitted a pure RM without DIF on any of the exogenous variables. Conclusions: Our results suggest that the 10-item PRIM-Depression scale should be used to compare cohorts only with appropriate score equation. The 8-item version provides a sufficient statistic and can as such be applied using the raw score.

Therapeutic Effects of Extinction Learning as a Model of Exposure Therapy in Rats

Current treatments for stress-related psychiatric disorders, such as depression and posttraumatic stress disorder (PTSD), are inadequate. Cognitive behavioral psychotherapies, including exposure therapy, are an alternative to pharmacotherapy, but the neurobiological mechanisms are unknown. Preclinical models demonstrating therapeutic effects of behavioral interventions are required to investigate such mechanisms. Exposure therapy bears similarity to extinction learning. Thus, we investigated the therapeutic effects of extinction learning as a behavioral intervention to model exposure therapy in rats, testing its effectiveness in reversing chronic stress-induced deficits in cognitive flexibility and coping behavior that resemble dimensions of depression and PTSD. Rats were fear-conditioned by pairing a tone with footshock, and then exposed to chronic unpredictable stress (CUS) that induces deficits in cognitive set-shifting and active coping behavior. They then received an extinction learning session as a therapeutic intervention by repeated exposure to the tone with no shock. Effects on cognitive flexibility and coping behavior were assessed 24 h later on the attentional set-shifting test or shock-probe defensive burying test, respectively. Extinction reversed the CUS-induced deficits in cognitive flexibility and coping behavior, and increased phosphorylation of ribosomal protein S6 in the medial prefrontal cortex (mPFC) of stress-compromised rats, suggesting a role for activity-dependent protein synthesis in the therapeutic effect. Inhibiting protein synthesis by microinjecting anisomycin into mPFC blocked the therapeutic effect of extinction on cognitive flexibility. These results demonstrate the utility of extinction as a model by which to study mechanisms underlying exposure therapy, and suggest these mechanisms involve protein synthesis in the mPFC, the further study of which may identify novel therapeutic targets.

Post-traumatic stress disorder and depression co-occurrence: Structural relations among disorder constructs and trait and symptom dimensions

OBJECTIVES

Post-traumatic stress disorder (PTSD) and major depressive disorder (MDD) in response to trauma co-occur at high rates. A better understanding of the nature of this co-occurrence is critical to developing an accurate conceptualization of the disorders. This study examined structural relations among the PTSD and MDD constructs and trait and symptom dimensions within the framework of the integrative hierarchical model of anxiety and depression.

DESIGN

Study participants completed clinician-rated and self-report measures during a pre-treatment assessment.

METHODS

The sample consisted of 200 treatment-seeking individuals with a primary DSM-IV PTSD diagnosis. Structural equation modelling was used to examine the relationship between the constructs.

RESULTS

The trait negative affect/neuroticism construct had a direct effect on both PTSD and MDD. The trait positive affect/extraversion construct had a unique, negative direct effect on MDD, and PTSD had a unique, direct effect on the physical concerns symptoms construct. An alternative model with the PTSD and MDD constructs combined into an overall general traumatic stress construct produced a decrement in model fit.

CONCLUSIONS

These findings provide a clearer understanding of the relationship between co-occurring PTSD and MDD as disorders with shared trait negative affect/neuroticism contributing to the overlap between them and unique trait positive affect/extraversion and physical concerns differentiating them. Therefore, PTSD and MDD in response to trauma may be best represented as two distinct, yet strongly related constructs.

PRACTITIONER POINTS

In assessing individuals who have been exposed to trauma, practitioners should recognize that co-occurring PTSD and MDD appears to be best represented as two distinct, yet strongly related constructs. Negative affect may be the shared vulnerability directly influencing both PTSD and MDD; however, in the presence of both PTSD and MDD, low positive affect appears to be more specifically related to MDD and fear of physical sensations to PTSD, which is information that could be used by practitioners in the determination of treatment approach. Overall, these findings are clinically relevant in that they may inform assessment, treatment planning, and ultimately diagnostic classification.

Comorbidity between post-traumatic stress disorder and major depressive disorder: alternative explanations and treatment considerations

Approximately half of people with post-traumatic stress disorder (PTSD) also suffer from Major Depressive Disorder (MDD). The current paper examines evidence for two explanations of this comorbidity. First, that the comorbidity reflects overlapping symptoms in the two disorders. Second, that the co-occurrence of PTSD and MDD is not an artifact, but represents a trauma-related phenotype, possibly a subtype of PTSD. Support for the latter explanation is inferred from literature that examines risk and biological correlates of PTSD and MDD, including molecular processes. Treatment implications of the comorbidity are considered.

Patients with Posttraumatic Stress Disorder with Comorbid Major Depressive Disorder Require a Higher Dose of Psychotropic Drugs

Major depressive disorder (MDD) has been associated with stressful life events and with posttraumatic stress disorder (PTSD). PTSD and MDD comorbidity was also reported to be associated with greater symptom severity and lower levels of functioning. However, the characteristics of pharmacotherapy for PTSD with MDD are not fully understood. To understand this relationship, we conducted a retrospective review using medical charts at the Department of Neuropsychiatry, Kurume University Hospital. Information from 55 patients with PTSD was analyzed. Five cases were excluded after re-evaluation of the PTSD diagnosis. A higher rate of type II trauma was observed in the PTSD with MDD group (50.0%) than in the PTSD-only group [13.6%; χ(2) (1, n =50) = 7.26, p<0.01]. Patients with comorbid MDD were significantly older, had more severe PTSD symptomatology, and a longer duration of treatment. They also received higher doses of psychotropic drugs, regardless of the type (antidepressants, antipsychotics, benzodiazepines), than the PTSD-only group. Our results showed that comorbid MDD is associated with higher doses of psychotropic drugs, suggesting difficulties in treatment.

Preliminary Evidence of Increased Hippocampal Myelin Content in Veterans with Posttraumatic Stress Disorder

Recent findings suggest the formation of myelin in the central nervous system by oligodendrocytes is a continuous process that can be modified with experience. For example, a recent study showed that immobilization stress increased oligodendrogensis in the dentate gyrus of adult rat hippocampus. Because changes in myelination represents an adaptive form of brain plasticity that has a greater reach in the adult brain than other forms of plasticity (e.g., neurogenesis), the objective of this “proof of concept” study was to examine whether there are differences in myelination in the hippocampi of humans with and without post-traumatic stress disorder (PTSD). We used the ratio of T1-weighted/T2-weighted magnetic resonance image (MRI) intensity to estimate the degree of hippocampal myelination in 19 male veterans with PTSD and 19 matched trauma-exposed male veterans without PTSD (mean age: 43 ± 12 years). We found that veterans with PTSD had significantly more hippocampal myelin than trauma-exposed controls. There was also found a positive correlation between estimates of hippocampal myelination and PTSD and depressive symptom severity. To our knowledge, this is the first study to examine hippocampal myelination in humans with PTSD. These results provide preliminary evidence for stress-induced hippocampal myelin formation as a potential mechanism underlying the brain abnormalities associated with vulnerability to stress.

Fear learning circuitry is biased toward generalization of fear associations in posttraumatic stress disorder

Fear conditioning is an established model for investigating posttraumatic stress disorder (PTSD). However, symptom triggers may vaguely resemble the initial traumatic event, differing on a variety of sensory and affective dimensions. We extended the fear-conditioning model to assess generalization of conditioned fear on fear processing neurocircuitry in PTSD. Military veterans (n=67) consisting of PTSD (n=32) and trauma-exposed comparison (n=35) groups underwent functional magnetic resonance imaging during fear conditioning to a low fear-expressing face while a neutral face was explicitly unreinforced. Stimuli that varied along a neutral-to-fearful continuum were presented before conditioning to assess baseline responses, and after conditioning to assess experience-dependent changes in neural activity. Compared with trauma-exposed controls, PTSD patients exhibited greater post-study memory distortion of the fear-conditioned stimulus toward the stimulus expressing the highest fear intensity. PTSD patients exhibited biased neural activation toward high-intensity stimuli in fusiform gyrus (P<0.02), insula (P<0.001), primary visual cortex (P<0.05), locus coeruleus (P<0.04), thalamus (P<0.01), and at the trend level in inferior frontal gyrus (P=0.07). All regions except fusiform were moderated by childhood trauma. Amygdala-calcarine (P=0.01) and amygdala-thalamus (P=0.06) functional connectivity selectively increased in PTSD patients for high-intensity stimuli after conditioning. In contrast, amygdala-ventromedial prefrontal cortex (P=0.04) connectivity selectively increased in trauma-exposed controls compared with PTSD patients for low-intensity stimuli after conditioning, representing safety learning. In summary, fear generalization in PTSD is biased toward stimuli with higher emotional intensity than the original conditioned-fear stimulus. Functional brain differences provide a putative neurobiological model for fear generalization whereby PTSD symptoms are triggered by threat cues that merely resemble the index trauma.

Examination of the interrelations between the factors of PTSD, major depression, and generalized anxiety disorder in a heterogeneous trauma-exposed sample using DSM 5 criteria

Exposure to traumatic events places individuals at high risk for multiple psychiatric disorders, including posttraumatic stress disorder (PTSD), major depressive disorder (MDD), and generalized anxiety disorder (GAD). The high rates of comorbidity among these conditions merit evaluation in order to improve diagnosis and treatment approaches. The current study evaluated the association between PTSD, MDD, and GAD factors as presented in the DSM 5. 602 trauma-exposed individuals who experienced an event that met Criterion A for the DSM 5 PTSD diagnosis were recruited through Amazon.com, Inc.'s Mechanical Turk (MTurk) to complete an assessment of the impact of stressful events on their lives. High interrelations were detected among the 4 PTSD factors, 2 MDD factors that corresponded to somatic and affective symptoms, and the single GAD factor. The affective factor of MDD was most strongly related to the emotional numbing factor of PTSD, whereas the somatic factor of MDD was most strongly related to the hyperarousal factor of PTSD. The GAD factor was most strongly related to the hyperarousal factor of PTSD, relative to the other PTSD factors. The strength of the interrelations between factors of the three disorders is largely a function of the overlap in symptoms and calls into question the uniqueness of negative affective symptoms of PTSD, MDD and GAD. Results suggest that improved understanding of the trauma reaction requires a focus on the unique presentation of each individual and assessment of multiple disorders.

The Relationship Between Posttraumatic Stress Symptoms and Physical Health in a Survey of U.S. Veterans of the Iraq and Afghanistan Era

BACKGROUND

Although a large body of literature has linked posttraumatic stress disorder (PTSD) with poor physical health among older veterans, less is known regarding the association between PTSD and health among relatively younger cohorts of veterans.

OBJECTIVE

The current study examined the association between PTSD and self-reported health among a sample of veterans who served in the recent conflicts in Iraq and Afghanistan.

METHOD

Veterans (N = 1030) who served in the wars in Iraq and Afghanistan completed measures of PTSD symptom severity and self-rated health between September 2009 and February 2010. Analyses examined the association between PTSD symptoms and health outcomes.

RESULTS

In analyses adjusted for age, sex, race, and combat exposure, PTSD symptom severity was positively related to the number of health conditions and health symptoms reported (ps<0.001). Additionally, in analyses adjusted for age, sex, race, combat exposure, number of health conditions, and number of health symptoms, PTSD symptom severity was associated with an increased likelihood of rating one's health as poor or fair and an increased likelihood of reporting that one's physical health limits participation in activities (ps<0.001).

CONCLUSION

These findings suggest that, consistent with previous research, PTSD symptom severity has a broad negative effect on physical health among veterans of the Iraq and Afghanistan era. Health promotion among veterans with PTSD may help attenuate risk of physical health consequences.