Mechanisms Underlying the Efficacy of Prolonged Exposure

Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18-90
SponsorVA Boston Healthcare System

About this trial

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.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

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

Disqualifiers

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,

Trial design

Design model

Single group

Treatments tested in this trial

  • Prolonged Exposure Therapy for Posttraumatic Stress Disorder

    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.

Treatment groups

50 Participants
are divided into 1 treatment group
Group A: Prolonged Exposure Therapy for Posttraumatic Stress DisorderExperimental treatment 1 intervention

Trial outcomes

Primary outcomes

1

Change from baseline in Clinician Administered PTSD Scale for DSM-5 (CAPS-5)

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.

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 outcomes

1

PTSD Checklist for DSM-5 (PCL-5)

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)

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.
2

QIDS-SR (93)

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)

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.
3

Prefrontal cortical activity during script-driven imagery (SDI)

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).

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.
4

Change in electrocardiography (ECG) and heart rate variability (HRV) during script driven imagery (SDI)

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.

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.

Other outcomes

Sponsors and contacts

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VA Boston Healthcare System

Lead sponsor

National Center for PTSD

Collaborator