Exposure Therapy for Chronic PTSD: Efficacy and Mechanisms

February 8, 2019 updated by: VA Office of Research and Development
The goals of the proposed research are to produce preliminary evidence of PE with OEF/OIF veterans with PTSD and to examine cognitive, psychophysiological, and neuroendocrine mechanisms of change in PTSD treatment. In brief, 36 OEF/OIF veterans with chronic PTSD or PTSS of at least 3 months duration will be randomly assigned to 15 sessions of either PE or TAU (see below for descriptions of the interventions). All veterans will receive psychobiological assessments at pre treatment, mid treatment, post treatment, 3 months, and 6 months follow-up. Each of these assessments will cover in 2 sessions on separate days and will include interview and self-report of symptoms (i.e., PTSD, depression, and general anxiety severity), self-report of PTSD-related cognitions, psychophysiological (i.e., heart rate, skin conductance, respiration, and end-tidal CO2) assessment during neutral and trauma scripts, and assessment of salivary cortisol during neutral and trauma scripts. Also, on the morning prior to each laboratory assessment, patients will collect salivary cortisol at the moment of waking and 30 and 45 minutes post-walking. In addition to these assessments, patients assigned to PE will collect salivary cortisol during three imaginal exposure sessions (sessions 3, 9, and 15).

Study Overview

Detailed Description

Effective treatments for PTSD are available, with exposure therapy (ET) programs, including Prolonged Exposure (PE), having the most empirical evidence for effectiveness (Rothbaum et al., 2000). However, among people receiving treatment for PTSD, many are not receiving psychotherapies with empirically proven efficacy. In one VA VISN, only 10% of PTSD specialist therapists reported using ET routinely (Rosen et al., 2004). They suggested that a lack of training and human resources to provide ET, as well as misconceptions about exposure therapy may drive the deficit. Training efforts would be substantially more cost-effective of the proven treatments could be delivered in group formats. Development and proof of efficacy of a group-based PE would provide far more veterans with access to a treatment that can truly foster recovery from the devastating impact of PTSD. This is a central goal of this proposal.

Little is known about the mechanisms through which PE leads to recovery. Delineation of its mechanisms is a critical step towards the development of treatment refinements to improve effectiveness and efficiency of the treatment. We plan to examine the potential roles of cognitive, psychophysiologic and neuroendocrine factors in symptom improvement. The mechanistic component will provide preliminary data on interactions between cognitive change (increased sense of self-competence and control over negative outcomes), psychophysiological habituation (reduced reactivity to trauma related stimuli), and reduced neuroendocrine sensitivity (reduced hypothalamic-pituitary-adrenal (HPA) axis reactivity). We predict that cognitive change, psychophysiological habituation and reduced HPA reactivity will all be related to symptom improvement with effective treatment.

Thirty-six OEF/OIF veterans with chronic PTSD of at least 3 months duration will be randomly assigned to 15 weeks of twice weekly PE-G or TAU. All veterans will receive psychobiological assessments at pre treatment, mid treatment, post treatment, 3 months and 6 months follow-up. Each of these assessments will include interview and self-report of symptoms (i.e., PTSD, depression, and general anxiety severity), self-report of PTSD-related cognitions, psychophysiological (i.e., heart rate, skin conductance, respiration, and end-tidal CO2) assessment during neutral and trauma scripts, and assessment of salivary cortisol during neutral and trauma scripts. Also, on the morning prior to each laboratory assessment, patients will collect salivary cortisol at the moment of waking and 30 and 45 minutes post-walking. The results from this study will be used as pilot data for VA Merit Award and NIMH R01 applications for larger follow-up studies.

Study Type

Interventional

Enrollment (Actual)

36

Phase

  • Phase 2
  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Michigan
      • Ann Arbor, Michigan, United States, 48113
        • VA Ann Arbor Healthcare System

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • OEF/OIF Veterans with combat related posttraumatic stress disorder (PTSD) or posttraumatic stress symptoms (PTSS) of at least 3 months duration with significant impairment (PSSI greater than or equal to 15).

Exclusion Criteria:

  • Any current level of personality disorder or suicidal risk that in the judgment of the investigator makes it unlikely or contraindicated that the patient can adhere to the study regimen.
  • Psychosis
  • Alcohol or substance dependence in the past 3 months
  • Working night-shifts
  • Changes to psychoactive medication in the past 8 weeks
  • Taking medication that makes HPA axis measures difficult to interpret

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Prolonged Exposure Therapy
Prolonged exposure therapy for PTSD
exposure-based treatment for PTSD
Active Comparator: Present Centered Therapy
Present centered therapy for PTSD
present focused coping and problem solving for PTSD

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Clinician Administered PTSD Scale (Pre & Posttreatment)
Time Frame: PostTreatment (Week 12)
Clinician Administered PTSD Scale (CAPS) assesses PTSD symptom severity. Scores range from 0 to 136 and higher scores represent more severe symptoms.
PostTreatment (Week 12)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Trauma Potentiated Startle
Time Frame: PostTreatment (Week 12)

Psychophysiological reactivity will be assessed using electromyography collected using a Biopac MP-100 physiology. The potentiation is recorded using a difference score (trauma probe response minus non-trauma probe response).

The unit of measure is µV. Higher is more response to trauma cue compared to non-trauma cue.

PostTreatment (Week 12)
Cortisol Response to Awakening
Time Frame: PostTreatment (Week 12)

Area under the curve for awakening, 30 min, and 45 minute salivary cortisol assays.

Higher means more cortisol response to awakening detected.

PostTreatment (Week 12)
Posttraumatic Cognitions Inventory
Time Frame: PostTreatment (Week 12)
Self-report measure of trauma-related cognitions. Range is 21-147. Higher is more problematic trauma-related cognitions.
PostTreatment (Week 12)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 2008

Primary Completion (Actual)

July 1, 2010

Study Completion (Actual)

July 1, 2010

Study Registration Dates

First Submitted

May 17, 2007

First Submitted That Met QC Criteria

May 17, 2007

First Posted (Estimate)

May 21, 2007

Study Record Updates

Last Update Posted (Actual)

February 15, 2019

Last Update Submitted That Met QC Criteria

February 8, 2019

Last Verified

February 1, 2019

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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