Abnormalities in whole-brain functional connectivity observed in treatment-naive post-traumatic stress disorder patients following an earthquake

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.

Intrinsic brain abnormalities in irritable bowel syndrome and effect of anxiety and depression

This resting-state functional magnetic resonance imaging (rs-fMRI) study investigated intrinsic brain abnormalities in irritable bowel syndrome (IBS) and effect of anxiety and depression. Thirty IBS patients and 31 matched healthy controls underwent rs-fMRI scanning. Regional brain activity was evaluated by measuring the amplitude of low-frequency fluctuation (ALFF) and compared between IBS patients and healthy controls with a two-sample t-test. Areas with abnormal ALFF were further used as seeds in subsequent inter-regional functional connectivity (FC) analysis. Statistical analyses were also performed by including anxiety and depression as covariates to evaluate their effect. Compared to healthy controls, IBS patients showed decreased ALFF in several core default mode network regions (medial prefrontal cortex [MPFC], posterior cingulate cortex [PCC], bilateral inferior parietal cortices [IPC]), and in middle frontal cortex, right orbital part of the superior frontal gyrus (ORBsup), dorsal anterior cingulate cortex (dACC), and ventral anterior cingulated cortex (vACC), while they showed increased ALFF in bilateral posterior insula and cuneus. In addition, IBS patients revealed decreased inter-regional positive FC between MPFC and right ORBsup, between vACC and PCC, as well as decreased negative FC between MPFC and left posterior insula, while they showed increased negative FC between MPFC and cuneus. The inclusion of anxiety and depression as covariates abolished ALFF differences in dACC and vACC, but none of the FC differences.

IN CONCLUSION

IBS patients had disturbed intrinsic brain function. High levels of anxiety and depression in IBS patients could account for their decreased intrinsic brain activity in regions (the ACC) involved in affective processing.

Disrupted cortical brain network in post-traumatic stress disorder patients: a resting-state electroencephalographic study

This study aimed to examine the source-level cortical brain networks of post-traumatic stress disorder (PTSD) based on the graph theory using electroencephalography (EEG). Sixty-six cortical source signals were estimated from 78 PTSD and 58 healthy controls (HCs) of resting-state EEG. Four global indices (strength, clustering coefficient (CC), path length (PL) and efficiency) and one nodal index (CC) were evaluated in six frequency bands (delta, theta, alpha, low beta, high beta and gamma). PTSD showed decreased global strength, CC and efficiency, in delta, theta, and low beta band and enhanced PL in theta and low beta band. In low beta band, the strength and CC correlated positively with the anxiety scores, while PL had a negative correlation. In addition, nodal CCs were reduced in PTSD in delta, theta and low beta band. Nodal CCs of theta band correlated negatively with rumination and re-experience symptom scores; while, nodal CCs in low beta band correlated positively with anxiety and pain severity. Inefficiently altered and symptom-dependent changes in cortical networks were seen in PTSD. Our source-level cortical network indices might be promising biomarkers for evaluating PTSD.

Altered default mode network configuration in posttraumatic stress disorder after earthquake: A resting-stage functional magnetic resonance imaging study

The neural substrates of posttraumatic stress disorder (PTSD) are still not fully elucidated. Hence, this study is to explore topological alterations of the default mode network (DMN) in victims with PTSD after a magnitude of 8.0 earthquake using resting-state functional magnetic resonance imaging (rs-fMRI).This study was approved by the local ethical review board, and all participants signed written informed consent. Sixty-two PTSD victims from the 2008 Sichuan earthquake and 62 matched exposed controls underwent rs-fMRI. PTSD was diagnosed by Clinician-Administered PTSD Scale, and underwent PTSD Checklist-Civilian Version for symptom scoring. The DMN was analyzed by using graph theoretical approaches. Further, Pearson correlation analysis was performed to correlate neuroimaging metrics to neuropsychological scores in victims with PTSD.Victims with PTSD showed decreased DMN functional connectivity strength between the right superior frontal gyrus and left inferior parietal lobule (IPL), and showed increased functional connectivity between the right IPL and precuneus or left posterior cingulate cortex. It was also found that victims with PTSD exhibited decreased nodal efficiency in right superior frontal gyrus and precuneus, and increased nodal efficiency in right hippocampus/parahippocampus. Apart from that, PTSD showed higher nodal degree in bilateral hippocampus/parahippocampus. In addition, the functional connectivity strength between the right IPL and precuneus correlated negatively to the avoid scores (r = -0.26, P = .04).This study implicates alteration of topological features on the DMN in PTSD victims after major earthquake, and provides new insights into DMN malfunction in PTSD based on graph theory.

Anomalous gray matter structural networks in recent onset post-traumatic stress disorder

Alterations of the topological organization of abnormal regions or network-level structural aberrations are still poorly understood for post-traumatic stress disorder (PTSD). Herein, we investigated brain structural networks in recent-onset PTSD patients, all affected by the coalmine-flood disaster. Cortical networks were studied in recent onset PTSD patients (n = 15) and matched healthy controls (n = 25). Cortical networks were constructed by thresholding correlation matrices of 150 regions and quantified using graph theoretical approaches. Contributions of high-degree nodes, and regional and global network measures, including degree and betweenness, were studied. Compared with healthy controls, PTSD patients showed altered quantitative values in global network properties, characterized by shorter path length and higher clustering. Moreover, PTSD patients exhibited decreased connectivity in the right lingual gyrus, parahippocampal gyrus, left supramarginal gyrus, parahippocampal gyrus, bilateral superior and inferior frontal gyrus, superior frontal gyrus, and posterior cingulate gyrus. Nodal centrality decreased predominantly in the occipital regions (lingual gyrus) and default-mode regions, while increased correlations and centralities were observed in the medial temporal lobe and posterior cingulate cortex. PTSD-related networks exhibited a less efficient organization and regional connectivity. According to these findings, we conclude that regional connections involving fear-processing and re-experiential-processing cortex may play a role in maintaining or adapting to PTSD pathology.

Network-Level Dysconnectivity in Drug-Naïve First-Episode Psychosis: Dissociating Transdiagnostic and Diagnosis-Specific Alterations

The neuroimaging literature provides compelling evidence for functional dysconnectivity in people with psychosis. However, it is likely that at least some of the observed alterations represent secondary effects of illness chronicity and/or antipsychotic medication. In addition, the extent to which these alterations are specific to psychosis or represent a transdiagnostic feature of psychiatric illness remains unclear. The aim of this study was therefore to examine the diagnostic specificity of functional dysconnectivity in drug-naïve first-episode psychosis (FEP). We used resting-state functional magnetic resonance imaging and functional connectivity analysis to estimate network-level connectivity in 50 patients with FEP, 50 patients with major depressive disorder (MDD), 50 patients with post-traumatic stress disorder (PTSD), and 122 healthy controls (HCs). The FEP, MDD, and PTSD groups showed reductions in intranetwork connectivity of the default mode network relative to the HC group (p<0.05 corrected); therefore, intranetwork alterations were expressed across the three diagnostic groups. In addition, the FEP group showed heightened internetwork connectivity between the default mode network, particularly the anterior cingulate cortex, and the central executive network relative to the MDD, PTSD, and HC groups (p<0.05 corrected); therefore, internetwork alterations were specific to the FEP. These findings suggest that network-level alterations are present in individuals with a first episode of psychosis who have not been exposed to antipsychotic medication. In addition, they suggest a dissociation between aberrant internetwork connectivity as a distinctive feature of psychosis and aberrant intranetwork connectivity as a transdiagnostic feature of psychiatric illness.

Rhythms dysregulation: A new perspective for understanding PTSD?

Post-traumatic stress disorder (PTSD) is a complex syndrome that may occur after exposure to one or more traumatic events. It associates physiological, emotional, and cognitive changes Brain and hormonal modifications contribute to some impairments in learning, memory, and emotion regulation. Some of these biological dysfunctions may be analyzed in terms of rhythms dysregulation that would be expressed through endocrine rhythmicity, sleep organization, and temporal synchrony in brain activity. In the first part of this article, we report studies on endocrine rhythmicity revealing that some rhythms abnormalities are frequently observed, although not constantly, for both cortisol and sympathetic nervous system (SNS) activity. The most typical changes are a flattening of the diurnal secretion of cortisol and the hyperactivation of the SNS. These results may explain why cognitive functioning, in particular consolidation of emotional memories, attention, learning, vigilance and arousal, is altered in patients with PTSD. The second part of this article focuses on sleep disturbances, one of the core features of PTSD. Abnormal REM sleep reported in various studies may have a pathophysiological role in PTSD and may exacerbate some symptoms such as emotional regulation and memory. In addition, sleep disorders, such as paradoxical insomnia, increase the risk of developing PTSD. We also discuss the potential impact of sleep disturbances on cognition. Finally, temporal synchrony of brain activity and functional connectivity, explored using electroencephalography and functional magnetic resonance imaging, are addressed. Several studies reported abnormalities in alpha, beta and gamma frequency bands that may affect both attentional and memory processes. Other studies confirmed abnormalities in connectivity and recent fMRI data suggest that this could limit top-down control and may be associated with flashback intrusive memories. These data illustrate that a better knowledge of the different patterns of biological rhythms contributes to explain the heterogeneity of PTSD and shed new light on the association with some frequent medical disorders.

Earthquake Brain: Altered Recognition and Misclassification of Facial Expressions Are Related to Trauma Exposure but Not Posttraumatic Stress Disorder

OBJECTIVES

The study investigated facial expression recognition (FER) in posttraumatic stress disorder (PTSD) caused by exposure to earthquakes, and in particular whether people with this condition showed a bias toward interpreting facial expressions as threat-related emotions (i.e., as anger, fear, or disgust). The study included a trauma-exposed control group who had been similarly exposed to the earthquakes but had not developed PTSD. We hypothesized that individuals with PTSD would have increased sensitivity to threat-related facial emotions compared with the trauma-exposed control group. This would be shown by increased accuracy in recognition of threat-related emotions and the misinterpretation of neutral expressions to these emotions (i.e., misidentifying them as anger, fear, or disgust). The availability of a group of healthy controls from a previous study who had been tested on a similar task before the earthquakes allowed a further non-exposed comparison.

METHOD

Twenty-eight individuals with PTSD (71% female, mean age 42.8 years) and 89 earthquake-exposed controls (66% female, mean age 50.1 years) completed an FER task, which featured six basic emotions. Further comparisons were made with 50 non-exposed controls (64% female, mean age 38.5 years) who had been tested before the earthquakes.

RESULTS

There was no difference in sensitivity to threat-related facial expressions (as measured by accuracy in recognition of threat-related facial expressions and the misinterpretation of neutral expressions as threatening) in individuals with PTSD compared with similarly earthquake-exposed controls. Supplementary comparison with an historical, non-exposed control group showed that both earthquake-exposed groups had increased accuracy for the identification of all facial emotions and showed a bias in the misclassification of neutral facial expressions to the threat-related emotions of anger and disgust.

CONCLUSION

These findings suggest that it is exposure to earthquakes and repeated aftershocks, rather than the presence of PTSD that affects FER accuracy and misinterpretation. The importance of these biases in both PTSD and trauma-exposed controls needs further exploration and is an area for future research.

Post-Traumatic Stress Disorder: The Relationship Between the Fear Response and Chronic Stress

Post-traumatic stress disorder (PTSD) is a disabling psychiatric condition that can develop following a physical, psychological, or sexual trauma. Despite the growing body of literature examining the psychological and biological factors involved in PTSD psychopathology, specific biomarkers that may improve diagnosis and treatment of PTSD have yet to be identified and validated. This challenge may be attributed to the diverse array of symptoms that individuals with the disorder manifest. Examining the interrelated stress and fear systems allows for a more comprehensive study of these symptoms, and through this approach, which aligns with the research domain criteria (RDoC) framework, neural and psychophysiological measures of PTSD have emerged. In this review, we discuss PTSD neurobiology and treatment within the context of fear and stress network interactions and elucidate the advantages of using an RDoC approach to better understand PTSD with fear conditioning and extinction paradigms.

Systematic Review on Post-Traumatic Stress Disorder Among Survivors of the Wenchuan Earthquake

Post-traumatic stress disorder (PTSD) widely occurs among victims or witness of disasters. With flashbacks, hyperarousal, and avoidance being the typical symptoms, PTSD became a focus of psychological research. The earthquake in Wenchuan, China, on May 12, 2008, was without precedent in magnitude and aftermath and caused huge damage, which drew scientists' attention to mental health of the survivors. We conducted a systematic overview by collecting published articles from the PubMed database and classifying them into five points: epidemiology, neuropathology, biochemistry, genetics and epigenetics, and treatment. The large body of research during the past 6 years showed that adolescents and adults were among the most studied populations with high prevalence rates for PTSD. Genomic and transcriptomic studies focusing on gene × environment studies as well as epigenetics are still rare, although a few available data showed great potential to better understand the pathophysiology of PTSD as multifactorial disease. Phytotherapy with Chinese herbs and acupuncture are rarely reported as of yet, although the first published data indicated promising therapy effects. Future studies should focus on the following points: (1) The affected populations under observation should be better defined concerning individual risk factor, time of observation, spatial movement, and individual disease courses of patients. (2) The role of social support for prevalence rates of PTSD should be observed in more detail. (3) Efficacy and safety of Chinese medicine should be studied to find potential interventions and effective treatments of PTSD.

Neurobiology of comorbid post-traumatic stress disorder and alcohol-use disorder

Post-traumatic stress disorder (PTSD) and alcohol-use disorder (AUD) are highly comorbid in humans. Although we have some understanding of the structural and functional brain changes that define each of these disorders, and how those changes contribute to the behavioral symptoms that define them, little is known about the neurobiology of comorbid PTSD and AUD, which may be due in part to a scarcity of adequate animal models for examining this research question. The goal of this review is to summarize the current state-of-the-science on comorbid PTSD and AUD. We summarize epidemiological data documenting the prevalence of this comorbidity, review what is known about the potential neurobiological basis for the frequent co-occurrence of PTSD and AUD and discuss successes and failures of past and current treatment strategies. We also review animal models that aim to examine comorbid PTSD and AUD, highlighting where the models parallel the human condition, and we discuss the strengths and weaknesses of each model. We conclude by discussing key gaps in our knowledge and strategies for addressing them: in particular, we (1) highlight the need for better animal models of the comorbid condition and better clinical trial design, (2) emphasize the need for examination of subpopulation effects and individual differences and (3) urge cross-talk between basic and clinical researchers that is reflected in collaborative work with forward and reverse translational impact.

Aberrant Functional Connectivity of the Amygdala Complexes in PTSD during Conscious and Subconscious Processing of Trauma-Related Stimuli

Post-traumatic stress disorder (PTSD) is characterized by altered functional connectivity of the amygdala complexes at rest. However, amygdala complex connectivity during conscious and subconscious threat processing remains to be elucidated. Here, we investigate specific connectivity of the centromedial amygdala (CMA) and basolateral amygdala (BLA) during conscious and subconscious processing of trauma-related words among individuals with PTSD (n = 26) as compared to non-trauma-exposed controls (n = 20). Psycho-physiological interaction analyses were performed using the right and left amygdala complexes as regions of interest during conscious and subconscious trauma word processing. These analyses revealed a differential, context-dependent responses by each amygdala seed during trauma processing in PTSD. Specifically, relative to controls, during subconscious processing, individuals with PTSD demonstrated increased connectivity of the CMA with the superior frontal gyrus, accompanied by a pattern of decreased connectivity between the BLA and the superior colliculus. During conscious processing, relative to controls, individuals with PTSD showed increased connectivity between the CMA and the pulvinar. These findings demonstrate alterations in amygdala subregion functional connectivity in PTSD and highlight the disruption of the innate alarm network during both conscious and subconscious trauma processing in this disorder.

ABERRANT RESTING-STATE BRAIN ACTIVITY IN POSTTRAUMATIC STRESS DISORDER: A META-ANALYSIS AND SYSTEMATIC REVIEW

BACKGROUND

About 10% of trauma-exposed individuals develop PTSD. Although a growing number of studies have investigated resting-state abnormalities in PTSD, inconsistent results suggest a need for a meta-analysis and a systematic review.

METHODS

We conducted a systematic literature search in four online databases using keywords for PTSD, functional neuroimaging, and resting-state. In total, 23 studies matched our eligibility criteria. For the meta-analysis, we included 14 whole-brain resting-state studies, reporting data on 663 participants (298 PTSD patients and 365 controls). We used the activation likelihood estimation approach to identify concurrence of whole-brain hypo- and hyperactivations in PTSD patients during rest. Seed-based studies could not be included in the quantitative meta-analysis. Therefore, a separate qualitative systematic review was conducted on nine seed-based functional connectivity studies.

RESULTS

The meta-analysis showed consistent hyperactivity in the ventral anterior cingulate cortex and the parahippocampus/amygdala, but hypoactivity in the (posterior) insula, cerebellar pyramis and middle frontal gyrus in PTSD patients, compared to healthy controls. Partly concordant with these findings, the systematic review on seed-based functional connectivity studies showed enhanced salience network (SN) connectivity, but decreased default mode network (DMN) connectivity in PTSD.

CONCLUSIONS

Combined, these altered resting-state connectivity and activity patterns could represent neurobiological correlates of increased salience processing and hypervigilance (SN), at the cost of awareness of internal thoughts and autobiographical memory (DMN) in PTSD. However, several discrepancies between findings of the meta-analysis and systematic review were observed, stressing the need for future studies on resting-state abnormalities in PTSD patients.

Real-Time fMRI Neurofeedback with War Veterans with Chronic PTSD: A Feasibility Study

Many patients with post-traumatic stress disorder (PTSD), especially war veterans, do not respond to available treatments. Here, we describe a novel neurofeedback (NF) intervention using real-time functional magnetic resonance imaging for treating and studying PTSD. The intervention involves training participants to control amygdala activity after exposure to personalized trauma scripts. Three combat veterans with chronic PTSD participated in this feasibility study. All three participants tolerated well the NF training. Moreover, two participants, despite the chronicity of their symptoms, showed clinically meaningful improvements, while one participant showed a smaller symptom reduction. Examination of changes in resting-state functional connectivity patterns revealed a normalization of brain connectivity consistent with clinical improvement. These preliminary results support feasibility of this novel intervention for PTSD and indicate that larger, well-controlled studies of efficacy are warranted.

The impact of cultural differences in self-representation on the neural substrates of posttraumatic stress disorder

A significant body of literature documents the neural mechanisms involved in the development and maintenance of posttraumatic stress disorder (PTSD). However, there is very little empirical work considering the influence of culture on these underlying mechanisms. Accumulating cultural neuroscience research clearly indicates that cultural differences in self-representation modulate many of the same neural processes proposed to be aberrant in PTSD. The objective of this review paper is to consider how culture may impact on the neural mechanisms underlying PTSD. We first outline five key affective and cognitive functions and their underlying neural correlates that have been identified as being disrupted in PTSD: (1) fear dysregulation; (2) attentional biases to threat; (3) emotion and autobiographical memory; (4) self-referential processing; and (5) attachment and interpersonal processing. Second, we consider prominent cultural theories and review the empirical research that has demonstrated the influence of cultural variations in self-representation on the neural substrates of these same five affective and cognitive functions. Finally, we propose a conceptual model that suggests that these five processes have major relevance to considering how culture may influence the neural processes underpinning PTSD.

Aberrant Spontaneous and Task-Dependent Functional Connections in the Anxious Brain

A number of brain regions have been implicated in the anxiety disorders, yet none of these regions in isolation has been distinguished as the sole or discrete site responsible for anxiety disorder pathology. Therefore, the identification of dysfunctional neural networks as represented by alterations in the temporal correlation of blood-oxygen level dependent (BOLD) signal across several brain regions in anxiety disorders has been increasingly pursued in the past decade. Here, we review task-independent (e.g., resting state) and task-induced functional connectivity magnetic resonance imaging (fcMRI) studies in the adult anxiety disorders (including trauma- and stressor-related and obsessive compulsive disorders). The results of this review suggest that anxiety disorder pathophysiology involves aberrant connectivity between amygdala-frontal and frontal-striatal regions, as well as within and between canonical "intrinsic" brain networks - the default mode and salience networks, and that evidence of these aberrations may help inform findings of regional activation abnormalities observed in the anxiety disorders. Nonetheless, significant challenges remain, including the need to better understand mixed findings observed using different methods (e.g., resting state and task-based approaches); the need for more developmental work; the need to delineate disorder-specific and transdiagnostic fcMRI aberrations in the anxiety disorders; and the need to better understand the clinical significance of fcMRI abnormalities. In meeting these challenges, future work has the potential to elucidate aberrant neural networks as intermediate, brain-based phenotypes to predict disease onset and progression, refine diagnostic nosology, and ascertain treatment mechanisms and predictors of treatment response across anxiety, trauma-related and obsessive compulsive disorders.

The Explorative Analysis to Revise Fear Network Model for Panic Disorder: Functional Connectome Statistics

Functional connectome analysis in panic disorder (PDO) is a relatively new field for research. We tried to investigate the functional connectome alterations in PDO to re-examine the precision and role of fear network model for the pathophysiology of PDO.We enrolled 53 PDO patients and 54 controls with imaging data in this study. After preprocessing, we calculated the connectivity matrix of functional connectivity in whole brain for each subject. Then network-based statistics (The University of Melbourne and Melbourne Health, Australia) of connectome was used to perform group comparisons between patients and controls. The correlation between network measures of significant subnetwork and illness duration or severity of PDO was also performed.Within the 6 network models, only 1 network survived after multiple corrections. We found decreased functional connectivity in the edges between the following nodes: the left parahippocampal gyrus, bilateral precentral gyri, bilateral middle cingulate gyri, bilateral supramarginal gyri, bilateral calcarine fissures, and right lingual gyrus. The central hubs were the left parahippocampal gyrus and left precentral gyrus. The importance of limbic areas and connection with sensory and motor regions might shed light on the revision of fear network model for the pathophysiology of PDO.

White Matter Abnormalities in Post-traumatic Stress Disorder Following a Specific Traumatic Event

Studies of posttraumatic stress disorder (PTSD) are complicated by wide variability in the intensity and duration of prior stressors in patient participants, secondary effects of chronic psychiatric illness, and a variable history of treatment with psychiatric medications. In magnetic resonance imaging (MRI) studies, patient samples have often been small, and they were not often compared to similarly stressed patients without PTSD in order to control for general stress effects. Findings from these studies have been inconsistent. The present study investigated whole-brain microstructural alterations of white matter in a large drug-naive population who survived a specific, severe traumatic event (a major 8.0-magnitude earthquake). Using diffusion tensor imaging (DTI), we explored group differences between 88 PTSD patients and 91 matched traumatized non-PTSD controls in fractional anisotropy (FA), as well as its component elements axial diffusivity (AD) and radial diffusivity (RD), and examined these findings in relation to findings from deterministic DTI tractography. Relations between white matter alterations and psychiatric symptom severity were examined. PTSD patients, relative to similarly stressed controls, showed an FA increase as well as AD and RD changes in the white matter beneath left dorsolateral prefrontal cortex and forceps major. The observation of increased FA in the PTSD group suggests that the pathophysiology of PTSD after a specific acute traumatic event is distinct from what has been reported in patients with several years duration of illness. Alterations in dorsolateral prefrontal cortex may be an important aspect of illness pathophysiology, possibly via the region's established role in fear extinction circuitry. Use-dependent myelination or other secondary compensatory changes in response to heightened demands for threat appraisal and emotion regulation may be involved.

Association of abnormal white matter integrity in the acute phase of motor vehicle accidents with post-traumatic stress disorder

BACKGROUND

A small portion of the Motor vehicle accidents (MVA) survivors would develop post-traumatic stress disorder (PTSD), which would cause substantial social function loss. How to identify those high-risk MVA survivors in the acute phase of the trauma is the first step to prevent the onset of PTSD. In the present study, we studied white matter integrity of subjects post to MVA by diffusional tensor imaging (DTI).

METHODS

To investigate whether the integrity of the white matter was impaired in the acute phase of the MVA among survivors who later develop PTSD and whether it could predict the severity of PTSD while being diagnosed. MVA Survivors were recruited to get trauma-specific clinical assessments and received DTI scan within 2 days from the MVA. These survivors were divided into 2 groups, PTSD group and trauma control (TC) group based on the clinical follow-up interview. Tract-Based Spatial Statistics (TBSS) was carried out to investigate difference in white matter integrity between 2 groups within DTI parameter maps. White matter integrity was measured by using fractional anisotropy (FA), axial diffusivity (AD), mean diffusivity (MD), and radical diffusivity (RD).

RESULTS

Compared with TC group, PTSD group showed lower FA value in multiple regions of both hemispheres, mainly involving anterior thalamic radiation, cortico-spinal tract, forceps minor, uncinate, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, cingulum and superior longitudinal fasciculus. Increased RD was also detected in PTSD group in the posterior part of right hemisphere, involving forceps major, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, cingulum, hippocampus and superior longitudinal fasciculus. The baseline FA and RD values correlated with Clinician-Administered PTSD Scale scores at clinical follow up.

CONCLUSION

MVA survivors who later developed PTSD had more abnormalities in white matter integrity in the acute phase than those non-PTSD MVA survivors. Imaging markers of white matter integrity might be helpful in early identification of MVA survivors at high risk of PTSD.

LIMITATIONS

Larger sample size in our extensive study is needed to confer a robust inference and image data at follow up are needed to observe the longitudinal changes of white matter integrity.

Abnormal functional architecture of amygdala-centered networks in adolescent posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is a prevalent, debilitating, and difficult to treat psychiatric disorder. Very little is known of how PTSD affects neuroplasticity in the developing adolescent brain. Whereas multiple lines of research implicate amygdala-centered network dysfunction in the pathophysiology of adult PTSD, no study has yet examined the functional architecture of amygdala subregional networks in adolescent PTSD. Using intrinsic functional connectivity analysis, we investigated functional connectivity of the basolateral (BLA) and centromedial (CMA) amygdala in 19 sexually abused adolescents with PTSD relative to 23 matched controls. Additionally, we examined whether altered amygdala subregional connectivity coincides with abnormal grey matter volume of the amygdaloid complex. Our analysis revealed abnormal amygdalar connectivity and morphology in adolescent PTSD patients. More specifically, PTSD patients showed diminished right BLA connectivity with a cluster including dorsal and ventral portions of the anterior cingulate and medial prefrontal cortices (p < 0.05, corrected). In contrast, PTSD patients showed increased left CMA connectivity with a cluster including the orbitofrontal and subcallosal cortices (p < 0.05, corrected). Critically, these connectivity changes coincided with diminished grey matter volume within BLA and CMA subnuclei (p < 0.05, corrected), with CMA connectivity shifts additionally relating to more severe symptoms of PTSD. These findings provide unique insights into how perturbations in major amygdalar circuits could hamper fear regulation and drive excessive acquisition and expression of fear in PTSD. As such, they represent an important step toward characterizing the neurocircuitry of adolescent PTSD, thereby informing the development of reliable biomarkers and potential therapeutic targets.

Functional network topology associated with posttraumatic stress disorder in veterans

Posttraumatic stress disorder (PTSD) is a disabling disorder associated with resting state functional connectivity alterations. However, whether specific brain regions are altered in PTSD or whether the whole brain network organization differs remains unclear. PTSD can be treated with trauma-focused therapy, although only half of the patients recover after treatment. In order to better understand PTSD psychopathology our aim was to study resting state networks in PTSD before and after treatment. Resting state functional magnetic resonance images were obtained from veterans with PTSD (n = 50) and controls (combat and civilian controls; n = 54) to explore which network topology properties (degree and clustering coefficient) of which brain regions are associated with PTSD. Then, PTSD-associated brain regions were investigated before and after treatment. PTSD patients were subdivided in persistent (n = 22) and remitted PTSD patients (n = 17), and compared with combat controls (n = 22), who were also reassessed. Prior to treatment associations with PTSD were found for the degree of orbitofrontal, and temporoparietal brain regions, and for the clustering coefficient of the anterior cingulate cortex. No significant effects were found over the course of treatment. Our results are in line with previous resting state studies, showing resting state connectivity alterations in the salience network and default mode network in PTSD, and also highlight the importance of other brain regions. However, network metrics do not seem to change over the course of treatment. This study contributes to a better understanding of the psychopathology of PTSD.

Topological Reorganization of the Default Mode Network in Irritable Bowel Syndrome

The aim of this study was to investigate the topological reorganization of the brain default mode network (DMN) in patients with irritable bowel syndrome (IBS) using resting-state functional magnetic resonance imaging (rs-fMRI). With approval by our ethics committee, rs-fMRI was prospectively performed in 31 IBS patients (25 male, 27 ± 8 years) and 32 healthy controls (25 male, 29 ± 9 years). The DMN was determined by unbiased seed-based functional connectivity (FC) analysis and then parcellated into several subregions. FC across all pairs of DMN subregions was computed to construct the DMN architecture, for which topological properties were characterized by graph theoretical approaches. Pearson correlation was performed between abnormal DMN inter-regional FC and network measures and clinical indices in IBS patients. Compared to healthy controls, IBS patients showed decreased DMN inter-regional FC between the anterior cingulate cortex and precuneus, the medial orbital of the superior frontal gyrus (ORBsupmed) and precuneus, and the middle temporal gyrus and precuneus. IBS patients also showed decreased DMN global efficiency (E _glob). Inclusion of anxiety and depression as covariates abolished FC between ORBsupmed and precuneus and some E _glob differences. The average DMN FC was positively correlated with average E _glob (r = 0.47, P = 0.008) and negatively correlated with symptom severity score (r = -0.37, P = 0.04) in IBS patients. In conclusion, IBS patients showed topological reorganization of the DMN to a non-optimized regularity configuration, which may partly be ascribed to high levels of anxiety and depression.

Inter-hemispheric functional and anatomical connectivity abnormalities in traffic accident-induced PTSD: a study combining fMRI and DTI

BACKGROUND

Aberrant brain functional and structural changes are considered to be one of the important mechanisms underlying post-traumatic stress disorder (PTSD). However, it remains unclear whether inter-hemispheric connection is changed. The current study aimed to identify the inter-hemispheric functional and anatomical connectivity changes in patients who consequently develop PTSD using the voxel-mirrored homotopic connectivity (VMHC) analysis and diffusion tractography techniques.

METHODS

Resting-state fMRI and DTI data were acquired on victims who had experienced traffic accidents within 2 days after the traumatic event. The diagnosis was made using the Clinician-Administered PTSD Scale at 1 or 6 months later. Fifteen trauma-exposed victims met the criteria for diagnosis of PTSD and 14 trauma-exposed victims who did not develop PTSD at 6 months after trauma were selected as the control group.

RESULTS

Compared with the victims without PTSD, the victims with PTSD exhibited an abnormal homotopic pattern with decreased VMHC in the superior/middle frontal gyrus before diagnosis. The regions showing abnormal functional connectivity were then chosen as regions of interest for an analysis of DTI tractography. Decreased fractional anisotropy values in the genu of the corpus callosum were found in the victims with PTSD. Greater WM disruptions within 2 days predicted greater symptom severity at diagnosis.

LIMITATIONS

The study was lack of comparison with controls who did not experience a traumatic event.

CONCLUSION

Our results suggest that the inter-hemispheric functional and structural connectivity is impaired in PTSD within 2 days, which may be the potential marker showing predisposition towards developing PTSD.

Intranetwork and internetwork functional connectivity alterations in post-traumatic stress disorder

BACKGROUND

A large number of previous neuroimaging studies have explored the functional alterations of post-traumatic stress disorder (PTSD). However, abnormalities in the functional architecture of resting-state networks in PTSD were rarely elucidated.

METHODS

This study used independent component analysis to explore the resting-state intranetwork and internetwork functional connectivity differences between 20 PTSD patients and 20 matched healthy controls (HCs).

RESULTS

Selective alterations of intranetwork and internetwork intrinsic functional connectivities were found in the PTSD patients. Compared with HCs, the PTSD patients exhibited significantly decreased network connectivity within the anterior default mode network, posterior default mode network (pDMN), salience network (SN), sensory-motor network, and auditory network. Furthermore, the PTSD patients exhibited increased internetwork connectivity between SN and pDMN.

LIMITATIONS

This study lacked recruitment of trauma-exposed HCs, which limits our ability to determine whether the alterations are caused by PTSD or trauma exposure.

CONCLUSION

The findings suggested that the PTSD patients exhibited abnormal functional connectivity at the brain network level. Notably, the enhanced internetwork connectivity between SN and pDMN in the PTSD patients may be associated with hyperarousal and heightened anxiety in PTSD.

Maternal sensitivity, infant limbic structure volume and functional connectivity: a preliminary study

Mechanisms underlying the profound parental effects on cognitive, emotional and social development in humans remain poorly understood. Studies with nonhuman models suggest variations in parental care affect the limbic system, influential to learning, autobiography and emotional regulation. In some research, nonoptimal care relates to decreases in neurogenesis, although other work suggests early-postnatal social adversity accelerates the maturation of limbic structures associated with emotional learning. We explored whether maternal sensitivity predicts human limbic system development and functional connectivity patterns in a small sample of human infants. When infants were 6 months of age, 20 mother-infant dyads attended a laboratory-based observational session and the infants underwent neuroimaging at the same age. After considering age at imaging, household income and postnatal maternal anxiety, regression analyses demonstrated significant indirect associations between maternal sensitivity and bilateral hippocampal volume at six months, with the majority of associations between sensitivity and the amygdala demonstrating similar indirect, but not significant results. Moreover, functional analyses revealed direct associations between maternal sensitivity and connectivity between the hippocampus and areas important for emotional regulation and socio-emotional functioning. Sensitivity additionally predicted indirect associations between limbic structures and regions related to autobiographical memory. Our volumetric results are consistent with research indicating accelerated limbic development in response to early social adversity, and in combination with our functional results, if replicated in a larger sample, may suggest that subtle, but important, variations in maternal care influence neuroanatomical trajectories important to future cognitive and emotional functioning.

Resting-State Functional Connectivity in Patients with Long-Term Remission of Cushing's Disease

Glucocorticoid disturbance can be a cause of psychiatric symptoms. Cushing's disease represents a unique model for examining the effects of prolonged exposure to high levels of endogenous cortisol on the human brain as well as for examining the relation between these effects and psychiatric symptomatology. This study aimed to investigate resting-state functional connectivity (RSFC) of the limbic network, the default mode network (DMN), and the executive control network in patients with long-term remission of Cushing's disease. RSFC of these three networks of interest was compared between patients in remission of Cushing's disease (n=24; 4 male, mean age=44.96 years) and matched healthy controls (n=24; 4 male, mean age=46.5 years), using probabilistic independent component analysis to extract the networks and a dual regression method to compare both groups. Psychological and cognitive functioning was assessed with validated questionnaires and interviews. In comparison with controls, patients with remission of Cushing's disease showed an increased RSFC between the limbic network and the subgenual subregion of the anterior cingulate cortex (ACC) as well as an increased RSFC of the DMN in the left lateral occipital cortex. However, these findings were not associated with psychiatric symptoms in the patient group. Our data indicate that previous exposure to hypercortisolism is related to persisting changes in brain function.

Distinct intrinsic network connectivity patterns of post-traumatic stress disorder symptom clusters

OBJECTIVE

Post-traumatic stress disorder (PTSD) is considered a multidimensional disorder, with distinct symptom clusters including re-experiencing, avoidance/numbing, hyperarousal, and most recently depersonalization/derealization. However, the extent of differing intrinsic network connectivity underlying these symptoms has not been fully investigated. We therefore investigated the degree of association between resting connectivity of the salience (SN), default mode (DMN), and central executive (CEN) networks and PTSD symptom severity.

METHOD

Using resting-state functional MRI data from PTSD participants (n = 21), we conducted multivariate analyses to test whether connectivity of extracted independent components varied as a function of re-experiencing, avoidance/numbing, hyperarousal, and depersonalization/derealization.

RESULTS

Hyperarousal symptoms were associated with reduced connectivity of posterior insula/superior temporal gyrus within SN [peak Montréal Neurological Institute (MNI): -44, -8, 0, t = -4.2512, k = 40]. Depersonalization/derealization severity was associated with decreased connectivity of perigenual anterior cingulate/ventromedial prefrontal cortex within ventral anterior DMN (peak MNI: 8, 40, -4; t = -3.8501; k = 15) and altered synchrony between two DMN components and between DMN and CEN.

CONCLUSION

Our results are consistent with prior research showing intrinsic network disruptions in PTSD and imply heterogeneous connectivity patterns underlying PTSD symptom dimensions. These findings suggest possible biomarkers for PTSD and its dissociative subtype.

Disrupted brain network topology in pediatric posttraumatic stress disorder: A resting-state fMRI study

Children exposed to natural disasters are vulnerable to the development of posttraumatic stress disorder (PTSD). Recent studies of other neuropsychiatric disorders have used graph-based theoretical analysis to investigate the topological properties of the functional brain connectome. However, little is known about this connectome in pediatric PTSD. Twenty-eight pediatric PTSD patients and 26 trauma-exposed non-PTSD patients were recruited from 4,200 screened subjects after the 2008 Sichuan earthquake to undergo a resting-state functional magnetic resonance imaging scan. Functional connectivity between 90 brain regions from the automated anatomical labeling atlas was established using partial correlation coefficients, and the whole-brain functional connectome was constructed by applying a threshold to the resultant 90 * 90 partial correlation matrix. Graph theory analysis was then used to examine the group-specific topological properties of the two functional connectomes. Both the PTSD and non-PTSD control groups exhibited "small-world" brain network topology. However, the functional connectome of the PTSD group showed a significant increase in the clustering coefficient and a normalized characteristic path length and local efficiency, suggesting a shift toward regular networks. Furthermore, the PTSD connectomes showed both enhanced nodal centralities, mainly in the default mode- and salience-related regions, and reduced nodal centralities, mainly in the central-executive network regions. The clustering coefficient and nodal efficiency of the left superior frontal gyrus were positively correlated with the Clinician-Administered PTSD Scale. These disrupted topological properties of the functional connectome help to clarify the pathogenesis of pediatric PTSD and could be potential biomarkers of brain abnormalities.

Diagnosis of posttraumatic stress disorder (PTSD) based on correlations of prewhitened fMRI data: outcomes and areas involved

Successful diagnosis of PTSD has been achieved using neural correlations from prewhitened magnetoencephalographic (MEG) time series (Georgopoulos et al. in J Neural Eng 7:16011, 2010. doi:10.1088/1741-2560/7/1/016011; James et al. 2015). Here, we show that highly successful classification of PTSD and control subjects can be obtained using neural correlations from prewhitened resting-state fMRI data. All but one PTSD (14/15; sensitivity = 93.3 %) and all but one control (20/21; specificity = 95.2 %) subjects were correctly classified using 15 out of 2701 possible correlations between 74 brain areas. In contrast, correlations of the same but non-prewhitened data yielded chance-level classifications. We conclude that, if properly processed, fMRI has the prospect of aiding significantly in PTSD diagnosis. Twenty-five brain areas were most prominently involved in correct subject classification, including areas from all cortical lobes and the left pallidum.

Disrupted Functional Brain Connectome in Patients with Posttraumatic Stress Disorder

PURPOSE

To use resting-state functional magnetic resonance (MR) imaging and graph theory approaches to systematically investigate the topological organization of the functional connectome of patients with posttraumatic stress disorder (PTSD).

MATERIALS AND METHODS

This study was approved by the research ethics committee, and all subjects provided informed consent for participation. Seventy-six patients with PTSD caused by an earthquake and 76 control subjects who experienced the same disaster were matched for age, sex, and years of education. The study subjects underwent resting-state functional MR imaging. The whole-brain functional network was then constructed by thresholding partial correlation matrices of 90 brain regions. The topological organization of the constructed network was analyzed by using graph theory approaches. Nonparametric permutation tests were also used for group comparisons of topological metrics.

RESULTS

Compared with the control subjects, patients with PTSD exhibited abnormalities in global properties, including a significant decrease in path length (P = .0002) and increases in the clustering coefficient (P = .0014), global efficiency (P = .0002), and local efficiency (P = .0004). Locally, the patients with PTSD exhibited increased centrality in nodes that are predominately involved in the default-mode network (DMN) and the salience network (SN), including the posterior cingulate gyrus, the precuneus, the insula, the putamen, the pallidum, and the temporal regions.

CONCLUSION

These results suggest that individuals with PTSD exhibit a shift toward "small-worldization" (in which the network transforms from a random or regular network to a small-world network) rather than toward randomization; furthermore, the disequilibrium between the DMN and the SN might be associated with the pathophysiology of PTSD.

Restoring large-scale brain networks in PTSD and related disorders: a proposal for neuroscientifically-informed treatment interventions

BACKGROUND

Three intrinsic connectivity networks in the brain, namely the central executive, salience, and default mode networks, have been identified as crucial to the understanding of higher cognitive functioning, and the functioning of these networks has been suggested to be impaired in psychopathology, including posttraumatic stress disorder (PTSD).

OBJECTIVE

1) To describe three main large-scale networks of the human brain; 2) to discuss the functioning of these neural networks in PTSD and related symptoms; and 3) to offer hypotheses for neuroscientifically-informed interventions based on treating the abnormalities observed in these neural networks in PTSD and related disorders.

METHODS

Literature relevant to this commentary was reviewed.

RESULTS

Increasing evidence for altered functioning of the central executive, salience, and default mode networks in PTSD has been demonstrated. We suggest that each network is associated with specific clinical symptoms observed in PTSD, including cognitive dysfunction (central executive network), increased and decreased arousal/interoception (salience network), and an altered sense of self (default mode network). Specific testable neuroscientifically-informed treatments aimed to restore each of these neural networks and related clinical dysfunction are proposed.

CONCLUSIONS

Neuroscientifically-informed treatment interventions will be essential to future research agendas aimed at targeting specific PTSD and related symptoms.

Amygdala and Dorsal Anterior Cingulate Connectivity during an Emotional Working Memory Task in Borderline Personality Disorder Patients with Interpersonal Trauma History

Working memory is critically involved in ignoring emotional distraction while maintaining goal-directed behavior. Antagonistic interactions between brain regions implicated in emotion processing, e.g., amygdala, and brain regions involved in cognitive control, e.g., dorsolateral and dorsomedial prefrontal cortex (dlPFC, dmPFC), may play an important role in coping with emotional distraction. We previously reported prolonged reaction times associated with amygdala hyperreactivity during emotional distraction in interpersonally traumatized borderline personality disorder (BPD) patients compared to healthy controls (HC): Participants performed a working memory task, while neutral versus negative distractors (interpersonal scenes from the International Affective Picture System) were presented. Here, we re-analyzed data from this study using psychophysiological interaction analysis. The bilateral amygdala and bilateral dorsal anterior cingulate cortex (dACC) were defined as seed regions of interest. Whole-brain regression analyses with reaction times and self-reported increase of dissociation were performed. During emotional distraction, reduced amygdala connectivity with clusters in the left dorsolateral and ventrolateral PFC was observed in the whole group. Compared to HC, BPD patients showed a stronger coupling of both seeds with a cluster in the right dmPFC and stronger positive amygdala connectivity with bilateral (para)hippocampus. Patients further demonstrated stronger positive dACC connectivity with left posterior cingulate, insula, and frontoparietal regions during emotional distraction. Reaction times positively predicted amygdala connectivity with right dmPFC and (para)hippocampus, while dissociation positively predicted amygdala connectivity with right ACC during emotional distraction in patients. Our findings suggest increased attention to task-irrelevant (emotional) social information during a working memory task in interpersonally traumatized patients with BPD.

Voxel-wise resting-state MEG source magnitude imaging study reveals neurocircuitry abnormality in active-duty service members and veterans with PTSD

Post-traumatic stress disorder (PTSD) is a leading cause of sustained impairment, distress, and poor quality of life in military personnel, veterans, and civilians. Indirect functional neuroimaging studies using PET or fMRI with fear-related stimuli support a PTSD neurocircuitry model that includes amygdala, hippocampus, and ventromedial prefrontal cortex (vmPFC). However, it is not clear if this model can fully account for PTSD abnormalities detected directly by electromagnetic-based source imaging techniques in resting-state. The present study examined resting-state magnetoencephalography (MEG) signals in 25 active-duty service members and veterans with PTSD and 30 healthy volunteers. In contrast to the healthy volunteers, individuals with PTSD showed: 1) hyperactivity from amygdala, hippocampus, posterolateral orbitofrontal cortex (OFC), dorsomedial prefrontal cortex (dmPFC), and insular cortex in high-frequency (i.e., beta, gamma, and high-gamma) bands; 2) hypoactivity from vmPFC, Frontal Pole (FP), and dorsolateral prefrontal cortex (dlPFC) in high-frequency bands; 3) extensive hypoactivity from dlPFC, FP, anterior temporal lobes, precuneous cortex, and sensorimotor cortex in alpha and low-frequency bands; and 4) in individuals with PTSD, MEG activity in the left amygdala and posterolateral OFC correlated positively with PTSD symptom scores, whereas MEG activity in vmPFC and precuneous correlated negatively with symptom score. The present study showed that MEG source imaging technique revealed new abnormalities in the resting-state electromagnetic signals from the PTSD neurocircuitry. Particularly, posterolateral OFC and precuneous may play important roles in the PTSD neurocircuitry model.

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Resting-state MEG detects abnormal electromagnetic activity in PTSD neurocircuitry

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PTSD showed hyperactivity in amygdala, hippocampus, and orbitofrontal cortex

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PTSD showed hypoactivity in vmPFC, frontal pole, and dlPFC

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PTSD symptom score correlated with MEG activity

Resting-state hippocampal connectivity correlates with symptom severity in post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is a serious mental health injury which can manifest after experiencing a traumatic life event. The disorder is characterized by symptoms of re-experiencing, avoidance, emotional numbing and hyper-arousal. Whilst its aetiology and resultant symptomology are better understood, relatively little is known about the underlying cortical pathophysiology, and in particular whether changes in functional connectivity may be linked to the disorder. Here, we used non-invasive neuroimaging with magnetoencephalography to examine functional connectivity in a resting-state protocol in the combat-related PTSD group (n = 23), and a military control group (n = 21). We identify atypical long-range hyperconnectivity in the high-gamma-band resting-state networks in a combat-related PTSD population compared to soldiers who underwent comparable environmental exposure but did not develop PTSD. Using graph analysis, we demonstrate that apparent network connectivity of relevant brain regions is associated with cognitive-behavioural outcomes. We also show that left hippocampal connectivity in the PTSD group correlates with scores on the well-established PTSD Checklist (PCL). These findings indicate that atypical synchronous neural interactions may underlie the psychological symptoms of PTSD, whilst also having utility as a potential biomarker to aid in the diagnosis and monitoring of the disorder.

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Soldiers with PTSD display increased connectivity in high gamma resting state.

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Left frontal, temporal and hippocampus regions show hyperconnectivity in PTSD.

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Emotionally-salient stimuli induced increased connectivity in soldiers without PTSD.

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Connectivity strength in left hippocampus correlates with PTSD symptom severity.

Characterization of post-traumatic stress disorder using resting-state fMRI with a multi-level parametric classification approach

Functional neuroimaging studies have found intra-regional activity and inter-regional connectivity alterations in patients with post-traumatic stress disorder (PTSD). However, the results of these studies are based on group-level statistics and therefore it is unclear whether PTSD can be discriminated at single-subject level, for instance using the machine learning approach. Here, we proposed a novel framework to identify PTSD using multi-level measures derived from resting-state functional MRI (fMRI). Specifically, three levels of measures were extracted as classification features: (1) regional amplitude of low-frequency fluctuations (univariate feature), which represents local spontaneous synchronous neural activity; (2) temporal functional connectivity (bivariate feature), which represents the extent of similarity of local activity between two regions, and (3) spatial functional connectivity (multivariate feature), which represents the extent of similarity of temporal correlation maps between two regions. Our method was evaluated on 20 PTSD patients and 20 demographically matched healthy controls. The experimental results showed that the features of each level could successfully discriminate PTSD patients from healthy controls. Furthermore, the combination of multi-level features using multi-kernel learning can further improve the classification performance. Specifically, the classification accuracy obtained by the proposed framework was 92.5 %, which was an increase of at least 5 and 17.5 % from the two-level and single-level feature based methods, respectively. Particularly, the limbic structure and prefrontal cortex provided the most discriminant features for classification, consistent with results reported in previous studies. Together, this study demonstrated for the first time that patients with PTSD can be identified at the individual level using resting-state fMRI data. The promising classification results indicated that this method may provide a complementary approach for improving the clinical diagnosis of PTSD.

Complex PTSD, affect dysregulation, and borderline personality disorder

Complex PTSD (cPTSD) was formulated to include, in addition to the core PTSD symptoms, dysregulation in three psychobiological areas: (1) emotion processing, (2) self-organization (including bodily integrity), and (3) relational security. The overlap of diagnostic criteria for cPTSD and borderline personality disorder (BPD) raises questions about the scientific integrity and clinical utility of the cPTSD construct/diagnosis, as well as opportunities to achieve an increasingly nuanced understanding of the role of psychological trauma in BPD. We review clinical and scientific findings regarding comorbidity, clinical phenomenology and neurobiology of BPD, PTSD, and cPTSD, and the role of traumatic victimization (in general and specific to primary caregivers), dissociation, and affect dysregulation. Findings suggest that BPD may involve heterogeneity related to psychological trauma that includes, but extends beyond, comorbidity with PTSD and potentially involves childhood victimization-related dissociation and affect dysregulation consistent with cPTSD. Although BPD and cPTSD overlap substantially, it is unwarranted to conceptualize cPTSD either as a replacement for BPD, or simply as a sub-type of BPD. We conclude with implications for clinical practice and scientific research based on a better differentiated view of cPTSD, BPD and PTSD.