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Background In a recent eye-tracking study we found a differential dwell time pattern for negatively-valenced and neutral faces among patients with posttraumatic stress disorder (PTSD), trauma-exposed healthy control (TEHCs), and healthy control (HC) participants. Here, we explored whether these group differences relate to resting-state functional connectivity (rsFC) patterns of brain areas previously linked to both attention processes and PTSD. These encompass the amygdala, dorsal anterior cingulate cortex (dACC), dorsolateral prefrontal cortex (dlPFC), ventrolateral prefrontal cortex (vlPFC), and nucleus accumbens (NAcc). Methods Ten minutes magnetic resonance imaging rsFC scans were recorded in 17 PTSD patients, 21 TEHCs, and 16 HCs. Participants then completed a free-viewing eye-tracking task assessing attention allocation outside the scanner. Dwell time on negatively-valenced stimuli (DT%) were assessed relative to functional connectivity in the aforementioned seed regions of interest (amygdala, dACC, dlPFC, vlPFC, and NAcc) to whole-brain voxel-wise rsFC. Results As previously reported, group differences occurred in attention allocation to negative-valence stimuli, with longer dwell time on negatively valence stimuli in the PTSD and TEHC groups than the HC group. Higher DT% correlated with weaker NAcc-orbitofrontal cortex (OFC) connectivity in patients with PTSD. Conversely, a positive association emerged in the HC group between DT% and NAcc-OFC connectivity. Conclusions While exploratory in nature, present findings may suggest that reward-related brain areas are involved in disengaging attention from negative-valenced stimuli, and possibly in regulating ensuing negative emotions.

BackgroundDespite 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.MethodsPTSD 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.ResultsThe 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.ConclusionsFlashbacks 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.

BackgroundThe hippocampus plays an important role in psychopathology and treatment outcome. While posterior hippocampus (PH) may be crucial for the learning process that exposure-based treatments require, affect-focused treatments might preferentially engage anterior hippocampus (AH). Previous studies have distinguished the different functions of these hippocampal sub-regions in memory, learning, and emotional processes, but not in treatment outcome. Examining two independent clinical trials, we hypothesized that anterior hippocampal volume would predict outcome of affect-focused treatment outcome [Interpersonal Psychotherapy (IPT); Panic-Focused Psychodynamic Psychotherapy (PFPP)], whereas posterior hippocampal volume would predict exposure-based treatment outcome [Prolonged Exposure (PE); Cognitive Behavioral Therapy (CBT); Applied Relaxation Training (ART)].MethodsThirty-five patients with posttraumatic stress disorder (PTSD) and 24 with panic disorder (PD) underwent structural magnetic resonance imaging (MRI) before randomization to affect-focused (IPT for PTSD; PFPP for PD) or exposure-based treatments (PE for PTSD; CBT or ART for PD). AH and PH volume were regressed with clinical outcome changes.ResultsBaseline whole hippocampal volume did not predict post-treatment clinical severity scores in any treatment. For affect-focused treatments, but not exposure-based treatments, anterior hippocampal volume predicted clinical improvement. Smaller AH correlated with greater affect-focused treatment improvement. Posterior hippocampal volume did not predict treatment outcome.ConclusionsThis is the first study to explore associations between hippocampal volume sub-regions and treatment outcome in PTSD and PD. Convergent results suggest that affect-focused treatment may influence the clinical outcome through the ‘limbic’ AH, whereas exposure-based treatments do not. These preliminary, theory-congruent, therapeutic findings require replication in a larger clinical trial.

BackgroundThe 11 September 2001 (9/11) attacks were unprecedented in magnitude and mental health impact. While a large body of research has emerged since the attacks, published reviews are few, and are limited by an emphasis on cross-sectional research, short time frame, and exclusion of treatment studies. Additionally, to date, there has been no systematic review of available longitudinal information as a unique data set. Consequently, knowledge regarding long-term trajectories of 9/11-related post-traumatic stress disorder (PTSD) among highly exposed populations, and whether available treatment approaches effectively address PTSD within the context of mass, man-made disaster, remains limited.MethodsThe present review aimed to address these gaps using a systematic review of peer-reviewed reports from October 2001 to May 2016. Eligible reports were of longitudinal studies of PTSD among highly exposed populations. We identified 20 reports of 9/11-related PTSD, including 13 longitudinal prevalence studies and seven treatment studies.ResultsFindings suggest a substantial burden of 9/11-related PTSD among those highly exposed to the attack, associated with a range of sociodemographic and back-ground factors, and characteristics of peri-event exposure. While most longitudinal studies show declining rates of prevalence of PTSD, studies of rescue/recovery workers have documented an increase over time. Treatment studies were few, and generally limited by methodological shortcomings, but support exposure-based therapies.ConclusionFuture directions for research, treatment, and healthcare policy are discussed.

BackgroundCognitive models of posttraumatic stress disorder (PTSD) implicate threat-related attentional biases in the etiology and phenomenology of the disorder. However, extant attentional research using reaction time (RT)-based paradigms and measures has yielded mixed results. Eye-tracking methodology has emerged in recent years to overcome several inherent drawbacks of RT-based tasks, striving to better delineate attentional processes.MethodsA systematic review of experimental studies examining threat-related attention biases in PTSD, using eye-tracking methodology and group-comparison designs, was conducted conforming to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Studies were selected following a systematic search for publications between 1980 and December 2017 in PsycINFO, MEDLINE and the National Center for PTSD Research's Published International Literature on Traumatic Stress (PILOTS) database. Additional records were identified by employing the Similar Articles feature in PubMed, and the Cited Reference Search in ISI Web of Science. Reference sections of review articles, book chapters and studies selected for inclusion were searched for further studies. Ongoing studies were also sought through Clinicaltrials.gov.ResultsA total of 11 studies (n= 456 participants in total) were included in the final review. Results indicated little support for enhanced threat detection, hypervigilance and attentional avoidance. However, consistent evidence emerged for sustained attention on threat (i.e. attention maintenance) in PTSD.ConclusionsThis review is the first to systematically evaluate extant findings in PTSD emanating from eye-tracking studies employing group-comparison designs. Results suggest that sustained attention on threat might serve as a potential target for therapeutic intervention.

BackgroundDisasters are traumatic events that may result in a wide range of mental and physical health consequences. Post-traumatic stress disorder (PTSD) is probably the most commonly studied post-disaster psychiatric disorder. This review aimed to systematically assess the evidence about PTSD following exposure to disasters.MethodA systematic search was performed. Eligible studies for this review included reports based on the DSM criteria of PTSD symptoms. The time-frame for inclusion of reports in this review is from 1980 (when PTSD was first introduced in DSM-III) and February 2007 when the literature search for this examination was terminated.ResultsWe identified 284 reports of PTSD following disasters published in peer-reviewed journals since 1980. We categorized them according to the following classification: (1) human-made disasters (n=90), (2) technological disasters (n=65), and (3) natural disasters (n=116). Since some studies reported on findings from mixed samples (e.g. survivors of flooding and chemical contamination) we grouped these studies together (n=13).ConclusionsThe body of research conducted after disasters in the past three decades suggests that the burden of PTSD among persons exposed to disasters is substantial. Post-disaster PTSD is associated with a range of correlates including sociodemographic and background factors, event exposure characteristics, social support factors and personality traits. Relatively few studies have employed longitudinal assessments enabling documentation of the course of PTSD. Methodological limitations and future directions for research in this field are discussed.