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NCT Number: NCT05788302

Mechanisms Underlying Efficacy of Prolonged Exposure

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 pretreatment 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.

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Key information

Conditions

Post Traumatic Stress Disorder Mental Disorders Stress Disorders, Post-Traumatic Stress Disorders, Traumatic Trauma and Stressor Related Disorders

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

MGH

Boston, Massachusetts, 02114, United States

Location status: Recruiting

Location contact

Amanda Baker, PhD

CONTACT

[email protected]

6176436703

About this study

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, midtreatment (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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age 18 or older
  • Meeting diagnostic criteria for PTSD as defined by DSM-5 assessed by the Diagnostic Interview for Anxiety, Mood, and Obsessive-compulsive and related Psychiatric Disorders (DIAMOND), and
  • Interest in starting PE

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 of moderate or greater severity assessed by the DIAMOND,
  • Active risk to self or others,
  • Current participation in therapy other than present-centered supportive 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

Treatment and study plan

Prolonged Exposure

Behavioral
  • 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, participants will begin imaginal exposures to their worst trauma memory. This involves the participant recounting and visualizing the trauma memory aloud with the clinician in the room for 30-40 minutes. The session will end with 15-20 minutes of processing the imaginal exposure. Participants will continue in-session imaginal exposures until the end of treatment. Throughout the treatment, participants will listen to a recording of their imaginal exposure and engage in in vivo exposures daily.

Primary outcomes

  1. 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.

    The primary clinical outcome, CAPS-5, is the gold standard clinical interview for assessing PTSD severity. In CAPS-5, each of the 20 symptoms of PTSD is rated on a 5-point severity scale ranging from 0 (absent) to 4 (extreme). Total scores range from 0 to 80.

Secondary outcomes

  1. 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.

    Self-ratings of how much one is bothered by each of the 20 symptoms of PTSD on a 5-point severity scale ranging from 0 (Not at all) to 4 (extremely)

  2. Quick Inventory of Depressive Symptomatology - Self report (QIDS-SR)

    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.]

    Used to measure severity of depressive symptoms. provides equivalent weightings (0-3) for each symptom item, gives clearly stated anchors that estimate the frequency and severity of symptoms, and includes all items required to diagnose a major depressive episode (approximately 5 minutes)

  3. 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.

    Prefrontal cortical (PFC) activity will be monitored during SDI procedures using NINscan portable brain and physiologic monitoring system via near infrared spectroscopy (NIRS) of the medial and lateral PFC. NIRS yields concentrations of oxygenated (oxyHb) and deoxygenated (deoxyHb) hemoglobin that can be used to assess cortical activation. Various portions of PFC (e.g. Brodmann areas 10, 46, 44, 45 and 47) have been shown to activate and/or deactivate during script-driven imagery (SDI) of an index trauma in persons with PTSD and to be associated with better PE outcome. NIRS data will be converted to quantitative oxy-Hb, deoxy-Hb, and total-Hb using the modified Beer-Lambert law. Changes in quantitative hemodynamic measure (oxy-Hb, deoxy-Hb, total-Hb) will be compared between 30 s of trauma-related SDI and their baseline epochs (30 s of silence preceding the respective script).

  4. 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.]

    ECG will be monitored during SDI procedures using NINscan portable brain and physiologic monitoring system. ECG will be collected continuously and the relative change calculated by subtracting the average ECG level for the 5 seconds immediately preceding SDI onset from the maximum level within 1 to 5 seconds after SDI onset. Heart rate variability (HRV) will be calculated form 5-minute epochs during baseline, calculating the standard deviation of all NN intervals, and comparing them to 5-minute intervals after onset of SDI. The ECG and HRV signals will be assessed individually and also in combination using posterior probability scores. Changes in ECG and HRV have been shown to indicate differential sympathetic reactivity in persons with PTSD versus controls.

  5. 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.

    SC will be monitored during SDI procedures using NINscan portable brain and physiologic monitoring system. SC level for the 5 seconds immediately preceding SDI onset from the maximum level within 1 to 5 seconds after SDI onset. This response window is selected to reduce the likelihood that response scores would be contaminated by spontaneous SC fluctuations. The signals will be assessed individually and also in combination using posterior probability scores. Changes in SC signals have been shown to indicate differential sympathetic reactivity in persons with PTSD versus controls.

  6. 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.

    Electromyography of the corrugator muscle will be monitored during SDI procedures using NINscan portable brain and physiologic monitoring system. An EMG response (EMGR) score will be calculated by subtracting the average EMG level for the 5 seconds immediately preceding SDI onset from the maximum level during SDI. The signals will be assessed individually and also in combination using posterior probability scores. Changes in corrugator EMG have been shown to indicate differential sympathetic reactivity in persons with PTSD versus controls.

  7. 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.

    Changes in respirometry will be monitored during SDI procedures using NINscan portable brain and physiologic monitoring system. Average frequency and signal amplitude during baseline and SDI exposure epochs will be compared to calculate the relative change in respirometry. Changes in respirometry have been shown to indicate differential sympathetic reactivity in persons with PTSD versus controls.

  8. Premature treatment dropout

    Time frame: Given at pre-treatment and mid-treatment (post session 5 in week 5 of treatment).

    Maintenance of active participation or dropout from the treatment will be assessed.

Study contacts

Contact information is provided by the study sponsor or research team.

Amanda W Baker, Ph.D.

CONTACT

[email protected]

617-643-6703

Vladimir Ivkovic, Ph.D.

CONTACT

[email protected]

617-724-5550

Sponsors and collaborators

Lead sponsor

Massachusetts General Hospital

Other

Registry information

Important dates

Study start
2023
Primary completion
2027
Study completion
2027
First posted
Mar 28, 2023
Registry last updated
Nov 13, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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