EEG and Actigraphy Biomarkers of Written Exposure Therapy for Posttraumatic Stress Disorder

NCT07766798 | Not Yet Recruiting

• 1 other identifier: 2026P001981
• Study Type: interventional
• Target: 200
• Locations: 1 country
• Sites: 1

Brief Summary

Posttraumatic stress disorder, or PTSD, can affect emotional health, sleep, daily functioning, and quality of life. Written Exposure Therapy is a brief trauma-focused psychotherapy in which participants complete structured writing exercises about a traumatic experience. However, it is not yet clear which changes in brain activity and sleep occur over the course of treatment or whether these measures can help predict who is most likely to benefit. This study will enroll approximately 200 adults with PTSD. Participants will be randomly assigned to either Written Exposure Therapy or a neutral writing condition and will complete five weekly writing sessions. The study will collect electroencephalography, or EEG, recordings and actigraphy-based sleep and activity measures at scheduled time points before treatment, during the five-week intervention period, and after treatment. Participants will also complete clinical assessments of PTSD symptoms and related outcomes. The primary goals are to identify EEG and sleep-related biomarkers associated with improvement in PTSD symptoms, determine how early these biomarkers change during treatment, and evaluate whether baseline measures can help predict individual treatment response.

Conditions

Posttraumatic Stress Disorder (PTSD)

Keywords

Written Exposure Therapy; Electroencephalography; Actigraphy; Treatment Response; Biomarkers

Outcome Measures

Primary Outcomes (20)

• Change in Clinician-Administered PTSD Scale for DSM-5 Total Severity Score

  Posttraumatic stress disorder symptom severity will be assessed using the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5). The total severity score ranges from 0 to 80, with higher scores indicating greater symptom severity. Change from baseline to post-intervention will be evaluated and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0) and post-intervention at Week 6

• Change in PTSD Checklist for DSM-5 Total Score

  Posttraumatic stress disorder symptom severity will be assessed using the 20-item PTSD Checklist for DSM-5 (PCL-5). Total scores range from 0 to 80, with higher scores indicating greater symptom severity. Change from baseline will be evaluated across study visits and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6

• Change in Resting-State EEG Delta Relative Power

  Resting-state EEG delta relative power will be quantified in the prespecified delta frequency band and reported as a percentage of total spectral power. Change from baseline will be evaluated across study visits and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6

• Change in Resting-State EEG Theta Relative Power

  Resting-state EEG theta relative power will be quantified in the prespecified theta frequency band and reported as a percentage of total spectral power. Change from baseline will be evaluated across study visits and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6

• Change in Resting-State EEG Alpha Relative Power

  Resting-state EEG alpha relative power will be quantified in the prespecified alpha frequency band and reported as a percentage of total spectral power. Change from baseline will be evaluated across study visits and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6

• Change in Resting-State EEG Beta Relative Power

  Resting-state EEG beta relative power will be quantified in the prespecified beta frequency band and reported as a percentage of total spectral power. Change from baseline will be evaluated across study visits and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6

• Change in Resting-State EEG Slow Gamma Relative Power

  Resting-state EEG slow gamma relative power will be quantified in the prespecified slow gamma frequency band and reported as a percentage of total spectral power. Change from baseline will be evaluated across study visits and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6

• Change in Resting-State EEG Fast Gamma Relative Power

  Resting-state EEG fast gamma relative power will be quantified in the prespecified fast gamma frequency band and reported as a percentage of total spectral power. Change from baseline will be evaluated across study visits and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6

• Change in Resting-State EEG Functional Connectivity

  Resting-state EEG functional connectivity will be quantified using Pearson correlation across channels. Functional connectivity values will be reported as dimensionless connectivity coefficients. Change from baseline will be evaluated across study visits and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6

• Change in Resting-State EEG Shannon Entropy

  Resting-state EEG Shannon entropy will be quantified from the EEG time series and reported as a dimensionless value. Change from baseline will be evaluated across study visits and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6

• Change in Resting-State EEG Rényi Entropy

  Resting-state EEG Rényi entropy will be quantified from the EEG time series and reported as a dimensionless value. Change from baseline will be evaluated across study visits and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6

• Change in Resting-State EEG Hjorth Mobility

  Resting-state EEG Hjorth mobility will be quantified from the EEG time series and reported as a dimensionless value. Change from baseline will be evaluated across study visits and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6

• Change in Resting-State EEG Hjorth Activity

  Resting-state EEG Hjorth activity will be quantified from the EEG time series. Hjorth activity reflects the variance of the EEG signal and will be reported in squared signal-amplitude units. Change from baseline will be evaluated across study visits and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6

• Change in Actigraphy-Derived Total Sleep Time

  Total sleep time will be estimated from wrist actigraphy and reported in minutes per night. Change from baseline will be evaluated across study visits and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6

• Change in Actigraphy-Derived Sleep Efficiency

  Sleep efficiency will be estimated from wrist actigraphy and reported as the percentage of time in bed spent asleep. Change from baseline will be evaluated across study visits and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6

• Change in Actigraphy-Derived Wake After Sleep Onset

  Wake after sleep onset will be estimated from wrist actigraphy and reported in minutes per night. Change from baseline will be evaluated across study visits and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6

• Change in Actigraphy-Derived Sleep Onset Latency

  Sleep onset latency will be estimated from wrist actigraphy and reported in minutes. Change from baseline will be evaluated across study visits and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6

• Change in Actigraphy-Derived Sleep Fragmentation

  Sleep fragmentation will be estimated from wrist actigraphy and reported as a sleep fragmentation index (dimensionless). Change from baseline will be evaluated across study visits and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6

• Change in Actigraphy-Derived Approximate Entropy

  Approximate entropy of actigraphy-derived sleep activity will be calculated from wrist actigraphy and reported as a dimensionless value. Change from baseline will be evaluated across study visits and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6

• Change in Actigraphy-Derived Sample Entropy

  Sample entropy of actigraphy-derived sleep activity will be calculated from wrist actigraphy and reported as a dimensionless value. Change from baseline will be evaluated across study visits and compared between the Written Exposure Therapy and neutral writing conditions.

  Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6

Study Arms (2)

Written Exposure Therapy

EXPERIMENTAL

Participants assigned to this arm will complete five weekly Written Exposure Therapy sessions. In each session, participants will complete structured writing exercises focused on a traumatic experience. EEG, actigraphy, and clinical assessments will be collected at scheduled time points before treatment, during the five-week intervention period, and after treatment.

Behavioral: Written Exposure Therapy

Neutral Writing Condition

ACTIVE COMPARATOR

Participants assigned to this arm will complete five weekly neutral writing sessions that do not involve trauma-focused exposure. EEG, actigraphy, and clinical assessments will be collected at scheduled time points before the intervention, during the five-week intervention period, and after the intervention.

Behavioral: Neutral Writing Condition

Interventions

Written Exposure Therapy BEHAVIORAL

Written Exposure Therapy consists of five weekly sessions in which participants complete structured writing exercises focused on a traumatic experience.

Written Exposure Therapy

Neutral Writing Condition BEHAVIORAL

The neutral writing condition consists of five weekly sessions in which participants complete structured writing exercises that do not involve trauma-focused exposure.

Neutral Writing Condition

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age between 18 and 65
• History of trauma, with current elevated PTSD symptoms
• Ability to understand and sign informed consent
• Ability to read and write in English
• Stable psychotropic medications for at least six weeks prior to enrollment

You may not qualify if:

• Metal in the head/neck
• Current unstable medical conditions
• Head injury with prolonged loss of consciousness (over 30 minutes) within the past 10 years
• History of major neurological illness
• History of seizures
• History of central nervous system (CNS) tumors
• History of stroke
• History of cerebral aneurysm
• Currently receiving trauma-focused therapy
• Current benzodiazepine use
• Currently receiving non-pharmacological treatment e.g. transcranial magnetic stimulation (TMS) or electroconvulsive therapy (ECT)
• Current moderate or severe substance use disorder
• Lifetime Bipolar I or primary psychotic illness
• Pregnancy

Sponsors & Collaborators

• Mclean Hospital: lead

Study Sites (1)

Oaks Building

Belmont, Massachusetts, 02478, United States

Location

MeSH Terms

Conditions

Stress Disorders, Post-Traumatic

Condition Hierarchy (Ancestors)

Stress Disorders, Traumatic; Trauma and Stressor Related Disorders; Mental Disorders

Central Study Contacts

Mohammad Sendi, PhD

CONTACT

617-855-4236; msendi@mclean.harvard.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: Clinician-administered outcome assessments will be conducted by assessors who are masked to participants' assigned study condition. Participants and intervention staff will be instructed not to disclose treatment assignment to the outcome assessors.
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Neuroscientist

Model Details: Participants will be randomly assigned in parallel to either Written Exposure Therapy or a neutral writing condition. Both groups will complete five weekly writing sessions and undergo EEG, actigraphy, and clinical assessments at scheduled time points before treatment, during the five-week intervention period, and after treatment.

Study Record Dates

• First Submitted: August 6, 2026
• First Posted: August 17, 2026
• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): July 30, 2031
• Study Completion (Estimated): September 30, 2031
• Last Updated: August 17, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, ANALYTIC CODE
• Time Frame: Data will be made available after study completion, anticipated in 2031, following completion of primary analyses and in accordance with NIH/NDA data-sharing requirements.

Locations

US (1)