An interventional study of Written Exposure Therapy and Neutral Writing Condition in Posttraumatic Stress Disorder (PTSD), sponsored by Mclean Hospital. Not yet recruiting at 1 site in United States. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-10-14.
Sponsored by Mclean Hospital · Not applicable, Interventional, and Basic science
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.
This randomized interventional study will examine neurophysiological and behavioral biomarkers of response to Written Exposure Therapy in adults with PTSD. Approximately 200 participants will be randomly assigned to Written Exposure Therapy or a neutral writing condition. Both conditions will involve five weekly writing sessions.
Participants will undergo repeated EEG assessments to measure brain activity and actigraphy monitoring to characterize sleep and daily activity. These assessments will occur at scheduled time points before treatment, during the five-week intervention period, and after treatment. Clinical assessments will include repeated measures of PTSD symptoms throughout the study and clinician-administered assessments before and after the intervention.
The study has three main objectives. First, it will evaluate changes in EEG and sleep measures from before to after the intervention and determine whether those changes are associated with improvement in PTSD symptoms. Second, it will examine weekly changes to identify the earliest point at which neurophysiological or sleep-related changes can be detected. Third, it will test whether baseline EEG, sleep, and clinical characteristics can predict treatment response and identify subgroups of participants with distinct response patterns.
The study is intended to improve understanding of the biological and behavioral mechanisms associated with Written Exposure Therapy and support the future development of personalized approaches to PTSD treatment.
2,682 studies on the registry are indexed under Stress Disorders, Post-Traumatic; 601 are open to participants now.
This study's planned enrollment of 200 is above the median of 69 across 2,196 interventional studies indexed under Stress Disorders, Post-Traumatic.
Browse Stress Disorders, Post-Traumatic studies →Mclean Hospital is the lead sponsor of 185 studies on the registry; 32 are open to participants now.
Of its 15 completed or terminated interventional studies of FDA-regulated products, 12 (80%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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
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
Written Exposure Therapy consists of five weekly sessions in which participants complete structured writing exercises focused on a traumatic experience.
The neutral writing condition consists of five weekly sessions in which participants complete structured writing exercises that do not involve trauma-focused exposure.
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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: Baseline (Week 0), treatment Weeks 1, 2, 3, 4, and 5, and post-intervention at Week 6
Plan to share: Yes — De-identified individual participant data will be shared through the National Institute of Mental Health (NIMH) Data Archive (NDA) in accordance with participant consent, institutional requirements, and applicable National Institutes of Health (NIH) data-sharing policies.
Supporting information: 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.
Data sharing details ↗ · nda.nih.gov
No publications or documents are linked to this record.
Start is estimated for Jan 2027; primary completion for Jul 2031, 54 months later.
Of 1,064 non-industry interventional studies with no phase under Stress Disorders, Post-Traumatic, half reached primary completion within 35 months of starting (the median), counting those still running; a quarter within 17 and three quarters within 53. This study's planned 54 months is above that.
Counting every sponsor, half of 1,092 studies reached it within 34 months; a quarter within 17 and three quarters within 53.
Start moved once since we started tracking on Sep 25, 2026: Sep 2026 → Jan 2027, on Oct 14, 2026.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Stress Disorders, Post-Traumatic →