JoAnn Difede

Confirmatory factor analysis of the PTSD Checklist and the Clinician-Administered PTSD Scale in disaster workers exposed to the World Trade Center Ground Zero

Although posttraumatic stress disorder (PTSD) factor analytic research has yielded little support for the DSM-IV 3-factor model of reexperiencing, avoidance, and hyperarousal symptoms, no clear consensus regarding alternative models has emerged. One possible explanation is differential instrumentation across studies. In the present study, the authors used confirmatory factor analysis to compare a self-report measure, the PTSD Checklist (PCL), and a structured clinical interview, the Clinician-Administered PTSD Scale (CAPS), in 2,960 utility workers exposed to the World Trade Center Ground Zero site. Although two 4-factor models fit adequately for each measure, the latent structure of the PCL was slightly better represented by correlated reexperiencing, avoidance, dysphoria, and hyperarousal factors, whereas that of the CAPS was slightly better represented by correlated reexperiencing, avoidance, emotional numbing, and hyperarousal factors. After accounting for method variance, the model specifying dysphoria as a distinct factor achieved slightly better fit. Patterns of correlations with external variables provided additional support for the dysphoria model. Implications regarding the underlying structure of PTSD are discussed.

Virtual reality exposure therapy for World Trade Center Post-traumatic Stress Disorder: a case report.

Done properly by experienced therapists, re-exposure to memories of traumatic events via imaginal exposure therapy can lead to a reduction of Post-traumatic Stress Disorder (PTSD) symptoms. Exposure helps the patient process and habituate to memories and strong emotions associated with the traumatic event: memories and emotions they have been carefully avoiding. But many patients are unwilling or unable to self-generate and re-experience painful emotional images. The present case study describes the treatment of a survivor of the World Trade Center (WTC) attack of 9-11-01 who had developed acute PTSD. After she failed to improve with traditional imaginal exposure therapy, we sought to increase emotional engagement and treatment success using virtual reality (VR) exposure therapy. Over the course of six 1-h VR exposure therapy sessions, we gradually and systematically exposed the PTSD patient to virtual planes flying over the World Trade Center, jets crashing into the World Trade Center with animated explosions and sound effects, virtual people jumping to their deaths from the burning buildings, towers collapsing, and dust clouds. VR graded exposure therapy was successful for reducing acute PTSD symptoms. Depression and PTSD symptoms as measured by the Beck Depression Inventory and the Clinician Administered PTSD Scale indicated a large (83%) reduction in depression, and large (90%) reduction in PTSD symptoms after completing VR exposure therapy. Although case reports are scientifically inconclusive by nature, these strong preliminary results suggest that VR exposure therapy is a promising new medium for treating acute PTSD. This study may be examined in more detail at www.vrpain.com.

Emerging treatments for PTSD

Recent innovations in posttraumatic stress disorder (PTSD) research have identified new treatments with significant potential, as well as novel enhancements to empirically-validated treatments. This paper reviews emerging psychotherapeutic and pharmacologic interventions for the treatment of PTSD. It examines the evidence for a range of interventions, from social and family-based treatments to technological-based treatments. It describes recent findings regarding novel pharmacologic approaches including propranolol, ketamine, prazosin, and methylenedioxymethamphetamine. Special emphasis is given to the description of virtual reality and D-cycloserine as enhancements to prolonged exposure therapy.

D-cycloserine augmentation of exposure therapy for post-traumatic stress disorder: a pilot randomized clinical trial.

Viewing post-traumatic stress disorder (PTSD) as a disorder of emotional learning, this study used a cognitive enhancer synergistically with virtual reality exposure (VRE) therapy for the treatment of PTSD. The main objective was to determine if a novel pharmacotherapy, D-cycloserine (DCS), enhanced the efficacy of the psychotherapy. Pre-clinical studies suggest that when fear extinction occurs during DCS administration, neuroplasticity may be enhanced. VRE therapy is a particularly promising format to test the hypothesis that DCS enhances extinction learning, as sensory fear cues are standardized across patients. In a pilot randomized, double-blind, placebo-controlled trial, 100 mg of DCS or placebo was administered 90 min before each weekly VRE session, to ensure peak plasma concentrations during the sessions in 25 patients with chronic PTSD. The primary outcome measure was the Clinician Administered PTSD Scale (CAPS). Secondary outcome measures included the Beck Depression Inventory-II and the State-Trait Anger Expression Inventory-2. Assessments occurred at pre-treatment, following sessions 3, 6, 10, post-treatment, and at 6 months. The difference in CAPS between the VRE-DCS (n=13) and VRE-placebo (n=12) groups increased over time beginning at 6 weeks, with medium to large between-group effect sizes immediately post-treatment and 6 months later (d=0.68 and d=1.13, respectively). A similar pattern was observed for depression, anger expression, and sleep. PTSD remission rates were significantly greater for the VRE-DCS group (46% vs 8% at post-treatment; 69% vs 17% at 6 months). Patients in the VRE-DCS group showed earlier and greater improvement in PTSD symptoms compared with the VRE-placebo group. These results suggest a promising new treatment for PTSD.

Effectiveness of Virtual Reality Exposure Therapy for Active Duty Soldiers in a Military Mental Health Clinic

Exposure therapy is an evidence-based treatment for posttraumatic stress disorder (PTSD), but research evaluating its effectiveness with active duty service members is limited. This report examines the effectiveness of virtual reality exposure therapy (VRE) for active duty soldiers (N = 24) seeking treatment following a deployment to Iraq or Afghanistan. Relative to their pretreatment self-reported symptoms on the PTSD Checklist, Military Version (M = 60.92; SD = 11.03), patients reported a significant reduction at posttreatment (M = 47.08; SD = 12.70; p < .001). Sixty-two percent of patients (n = 15) reported a reliable change of 11 points or more. This study supports the effectiveness of exposure therapy for active duty soldiers and extends previous research on VRE to this population.

The nature and course of subthreshold PTSD

This study investigated rates of subthreshold PTSD and associated impairment in comparison to no PTSD and full PTSD and prospectively followed the course of subthreshold symptoms over 3 years. 3360 workers dispatched to the WTC site following 9/11 completed clinician interviews and self-report measures at three time points each one year apart. At Time 1, 9.7% of individuals met criteria for subthreshold PTSD. The no PTSD, subthreshold PTSD, and full PTSD groups exhibited significantly different levels of impairment, rates of current MDD diagnosis, and self-reported symptoms of depression. At Time 2, 29% of the initial sample with subthreshold PTSD continued to meet criteria for subthreshold or full PTSD; at Time 3, this was true for 24.5% of the initial sample. The study lends credence to the clinical significance of subthreshold PTSD and emphasizes that associated impairment may be significant and longstanding. It also confirms clinical differences between subthreshold and full PTSD.

Variant brain-derived neurotrophic factor Val66Met endophenotypes: implications for posttraumatic stress disorder

Recently, a common single nucleotide polymorphism (SNP) has been identified in the gene encoding brain‐derived neurotrophic factor (BDNF). The variant BDNFMet has been shown to have decreased activity‐dependent BDNF secretion from neurons and to lead to impairments in specific forms of learning and altered susceptibility to stress. A mouse model containing BDNFMet has also been linked to increased anxiety‐like behavior. In a translational study, mice and human carriers of the BDNFMet allele were compared in their ability to extinguish a learned fear memory. Both showed slower suppression of the learned fear response. In humans, the neural correlates of this behavior were validated using fMRI. As anxiety and fear extinction lie at the core of symptoms and therapeutic approaches to posttraumatic stress disorder (PTSD), we propose that BDNF genotype and neuroimaging may be useful as biomarkers to provide guidance for more customized therapeutic directions. The aim of this paper is to review the available knowledge on the BDNF Val66Met SNP, with emphasis on anxiety‐ and fear‐related endophenotypes and its potential implications for PTSD.

Development and early evaluation of the Virtual Iraq/Afghanistan exposure therapy system for combat-related PTSD.

Numerous reports indicate that the growing incidence of posttraumatic stress disorder (PTSD) in returning Operation Enduring Freedom (OEF)/Operation Iraqi Freedom (OIF) military personnel is creating a significant health care and economic challenge. These findings have served to motivate research on how to better develop and disseminate evidence‐based treatments for PTSD. Virtual reality‐delivered exposure therapy for PTSD has been previously used with reports of positive outcomes. The current paper will detail the development and early results from use of the Virtual Iraq/Afghanistan exposure therapy system. The system consists of a series of customizable virtual scenarios designed to represent relevant Middle Eastern contexts for exposure therapy, including a city and desert road convoy environment. The process for gathering user‐centered design feedback from returning OEF/OIF military personnel and from a system deployed in Iraq (as was needed to iteratively evolve the system) will be discussed, along with a brief summary of results from an open clinical trial using Virtual Iraq with 20 treatment completers, which indicated that 16 no longer met PTSD checklist‐military criteria for PTSD after treatment.

Virtual Reality Goes to War: A Brief Review of the Future of Military Behavioral Healthcare

Numerous reports indicate that the incidence of posttraumatic stress disorder (PTSD) in returning OEF/OIF military personnel is creating a significant healthcare challenge. These findings have served to motivate research on how to better develop and disseminate evidence-based treatments for PTSD. Virtual Reality delivered exposure therapy for PTSD has been previously used with reports of positive outcomes. This article details how virtual reality applications are being designed and implemented across various points in the military deployment cycle to prevent, identify and treat combat-related PTSD in OIF/OEF Service Members and Veterans. The summarized projects in these areas have been developed at the University of Southern California Institute for Creative Technologies, a U.S. Army University Affiliated Research Center, and this paper will detail efforts to use virtual reality to deliver exposure therapy, assess PTSD and cognitive function and provide stress resilience training prior to deployment.

Virtual Reality Exposure Therapy for Post-Traumatic Stress Disorder and Other Anxiety Disorders

Anxiety disorders, including phobias and post-traumatic stress disorder, are common and disabling disorders that often involve avoidance behavior. Cognitive-behavioral treatments, specifically imaginal and in vivo forms of exposure therapy, have been accepted and successful forms of treatment for these disorders. Virtual reality exposure therapy, an alternative to more traditional exposure-based therapies, involves immersion in a computer-generated virtual environment that minimizes avoidance and facilitates emotional processing. In this article, we review evidence on the application of virtual reality exposure therapy to the treatment of specific phobias and post-traumatic stress disorder and discuss its advantages and cautions.