Mechanisms Underlying the Efficacy of Prolonged Exposure

Overview

The primary objective of this research is to collect pilot data that demonstrates that proposed neural, psychophysiological and subjective markers measured before, during, and after treatment change over the course of Prolonged Exposure therapy (PE) for posttraumatic stress disorder (PTSD). The aims of the study are to: (1) examine theoretically informed mechanisms as pre-treatment predictors of PE treatment efficacy, (2) characterize how neural, psychophysiological, and subjective markers measured before, during, and after treatment change over the course of PE, and (3) examine proposed mechanisms of change as measures of PE treatment efficacy. This is a longitudinal study of predictors of exposure therapy efficacy that will be conducted within the context of a standard 10 session PE treatment trial, with independent multimodal assessment batteries administered at pre-treatment, mid-treatment, post-treatment, and at 1-month follow-up. This data will be used to support a future NIMH and/or VA grant submission.

Detailed description

Proposed research sets to collect pilot data to examine how the proposed neural, psychophysiological and subjective markers measured before, during, and after treatment change over the course of Prolonged Exposure (PE) therapy for posttraumatic stress disorder (PTSD). Fifty participants will be screened with the goal of obtaining 15 participants to complete the study. Participants will complete ten 60-minute sessions of PE. During each PE session, participants will be outfitted with a NINscan device to record psychophysiological measures including skin conductance, heart rate, and facial EMG, as well as neural measures of LPFC activity. Multimodal assessment batteries will be scheduled to take place at pre-treatment, mid-treatment (i.e., post session 5), post-treatment (i.e., post-session 10), and at 1-month follow-up. These sessions will include a battery of self-report measures, clinician-administered diagnostic interviews, and script-driven imagery (SDI) procedures with physiologic and neural recordings. The primary outcome measure will be PTSD symptom change on the CAPS-5 and the secondary outcome measures will be a) change in self-reported symptom severity, b) premature treatment dropout, and c) change in psychophysiological reactivity and LPFC activity during the SDI procedures. This proposed research will inform theoretical models of exposure therapy efficacy, with the goal of enhancing prolonged exposure therapy.

Interventions

• Behavioral Prolonged Exposure Therapy for Posttraumatic Stress Disorder
  Participation will occur throughout 17 weeks over 15 separate visits during which 10, 60-minute sessions of PE will take place. Session 1 of PE will focus on psychoeducation. Session 2 of PE will involve a continuation of psychoeducation and rationale for exposure as well as the collaborative construction of the in vivo exposure hierarchy. After session 2, participants will begin homework where they are instructed to confront situations on their hierarchy. Starting in session 3 of PE, participan

Primary outcome measures

• Change from baseline in Clinician Administered PTSD Scale for DSM-5 (CAPS-5) [Time frame: Given during screening session, pre-treatment, mid-treatment (post session 5 in week 5 of treatment), post-treatment (post session 10 in week 10 of treatment), and at 1-month follow up.]

Secondary outcome measures (8)

• PTSD Checklist for DSM-5 (PCL-5) [Time frame: Given during screening session, pre-treatment, mid-treatment (post session 5 in week 5 of treatment), post-treatment (post session 10 in week 10 of treatment), and at 1-month follow up.]
• QIDS-SR (93) [Time frame: Given during screening session, pre-treatment, mid-treatment (post session 5 in week 5 of treatment), post-treatment (post session 10 in week 10 of treatment), and at 1-month follow up.]
• Prefrontal cortical activity during script-driven imagery (SDI) [Time frame: Given during screening session, pre-treatment, mid-treatment (post session 5 in week 5 of treatment), post-treatment (post session 10 in week 10 of treatment), and at 1-month follow up.]
• Change in electrocardiography (ECG) and heart rate variability (HRV) during script driven imagery (SDI) [Time frame: Given during screening session, pre-treatment, mid-treatment (post session 5 in week 5 of treatment), post-treatment (post session 10 in week 10 of treatment), and at 1-month follow up.]
• Change in skin conductance (SC) during script-driven imagery (SDI) [Time frame: Given during screening session, pre-treatment, mid-treatment (post session 5 in week 5 of treatment), post-treatment (post session 10 in week 10 of treatment), and at 1-month follow up.]
• Change in electromyography (EMG) during script-driven imagery (SDI) [Time frame: Given during screening session, pre-treatment, mid-treatment (post session 5 in week 5 of treatment), post-treatment (post session 10 in week 10 of treatment), and at 1-month follow up.]
• Change in respirometry during script-driven imagery (SDI) [Time frame: Given during screening session, pre-treatment, mid-treatment (post session 5 in week 5 of treatment), post-treatment (post session 10 in week 10 of treatment), and at 1-month follow up.]
• Premature treatment dropout [Time frame: Given at pre-treatment and mid-treatment (post session 5 in week 5 of treatment).]

Eligibility criteria

Inclusion criteria

• a diagnosis of PTSD as defined by DSM-5 (as indicated by meeting diagnostic criteria on the CAPS-5)
• interest in starting PE (as indicated during the informed consent process)
• Veteran

Exclusion criteria

• Current or past history of schizophrenic or other psychotic disorders,
• Untreated Bipolar Disorder or a history of a manic/mixed episode within the last 6 months,
• Severe traumatic brain injury,
• Major neurological problems,
• Current substance use disorder,
• Active risk to self or others,
• Current participation in cognitive-behavioral therapy,
• Previously received > 2 sessions of Prolonged Exposure, and
• Having no memory of their traumatic event.
• For participants who are currently prescribed psychotropic medication, they will be eligible for the study provided medication use has been stable for 2 months prior to enrollment and remains stable throughout participation

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

N/A

Model

Single group

Masking

Open label

Primary purpose

Treatment

Study locations

United States · 1 center

• VA Boston Healthcare System — Boston

Publications

• Powers MB, Halpern JM, Ferenschak MP, Gillihan SJ, Foa EB. A meta-analytic review of prolonged exposure for posttraumatic stress disorder. Clin Psychol Rev. 2010 Aug;30(6):635-41. doi: 10.1016/j.cpr.2010.04.007. Epub 2010 May 2. PMID 20546985
• Hembree EA, Foa EB, Dorfan NM, Street GP, Kowalski J, Tu X. Do patients drop out prematurely from exposure therapy for PTSD? J Trauma Stress. 2003 Dec;16(6):555-62. doi: 10.1023/B:JOTS.0000004078.93012.7d. PMID 14690352
• Schnurr PP, Friedman MJ, Engel CC, Foa EB, Shea MT, Chow BK, Resick PA, Thurston V, Orsillo SM, Haug R, Turner C, Bernardy N. Cognitive behavioral therapy for posttraumatic stress disorder in women: a randomized controlled trial. JAMA. 2007 Feb 28;297(8):820-30. doi: 10.1001/jama.297.8.820. PMID 17327524
• Kehle-Forbes SM, Meis LA, Spoont MR, Polusny MA. Treatment initiation and dropout from prolonged exposure and cognitive processing therapy in a VA outpatient clinic. Psychol Trauma. 2016 Jan;8(1):107-114. doi: 10.1037/tra0000065. Epub 2015 Jun 29. PMID 26121175
• Schottenbauer MA, Glass CR, Arnkoff DB, Tendick V, Gray SH. Nonresponse and dropout rates in outcome studies on PTSD: review and methodological considerations. Psychiatry. 2008 Summer;71(2):134-68. doi: 10.1521/psyc.2008.71.2.134. PMID 18573035
• Bouton ME, Mineka S, Barlow DH. A modern learning theory perspective on the etiology of panic disorder. Psychol Rev. 2001 Jan;108(1):4-32. doi: 10.1037/0033-295x.108.1.4. PMID 11212632
• McGuire JF, Lewin AB, Storch EA. Enhancing exposure therapy for anxiety disorders, obsessive-compulsive disorder and post-traumatic stress disorder. Expert Rev Neurother. 2014 Aug;14(8):893-910. doi: 10.1586/14737175.2014.934677. Epub 2014 Jun 27. PMID 24972729
• Rachman S. Emotional processing. Behav Res Ther. 1980;18(1):51-60. doi: 10.1016/0005-7967(80)90069-8. No abstract available. PMID 7369988

Identifiers

NCT: NCT05663151 · 1577670

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗