A Phase 4 interventional study of Suvorexant and Placebo in PTSD - Post Traumatic Stress Disorder, Insomnia and TBI (Traumatic Brain Injury), sponsored by Northern California Institute of Research and Education. Not yet recruiting at 1 site in United States. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-07-07.
Sponsored by Northern California Institute of Research and Education · Phase 4, Interventional, and Treatment
The goal of this clinical trial is to learn if combining suvorexant (a sleep medication) with a shorter form of prolonged exposure therapy called PE-PC works to treat PTSD symptoms and improve sleep in Veterans and military personnel with PTSD and insomnia, with and without mild-to-moderate traumatic brain injury (TBI). The main questions it aims to answer are:
Does suvorexant, when combined with PE-PC therapy, reduce PTSD symptoms more than PE-PC with a placebo (a look-alike substance that contains no drug)? Does suvorexant, when combined with PE-PC therapy, improve psychosocial and physical functioning more than PE-PC with a placebo?
Researchers will compare PE-PC combined with suvorexant to PE-PC combined with a placebo to see if adding suvorexant improves PTSD symptoms, sleep, and overall functioning in Veterans.
Participants will:
Receive weekly PE-PC therapy sessions for 8 weeks Take suvorexant (10-20 mg) or a placebo each night during the 8-week treatment period.
Complete repeated assessments of PTSD symptoms, sleep, and psychosocial and physical functioning throughout the study.
Insomnia is the most prevalent symptom endorsed by PTSD patients and is highly prevalent in TBI, resulting in impairments in many domains of overall health and functioning. Prolonged exposure for primary care (PE-PC) is a shorter version of traditional PE that has demonstrated efficacy in the treatment of PTSD, related conditions (e.g., insomnia, depression), and improving functioning when compared to treatment as usual (e.g., PE, cognitive behavioral therapy for insomnia) in Veterans. However, challenges for PTSD interventions remain as some symptoms, particularly arousal and sleep-related difficulties, often fail to remit, with only 40-60% of Veterans showing clinically significant improvements following treatment, in addition to high attrition rates from these interventions. An integrated treatment that incorporates a pharmacological intervention that improves sleep during PE-PC may provide the greatest opportunity to facilitate recovery, by both increasing Veterans' engagement in treatment and supporting the extinction learning and consolidation mechanisms that promote recovery.
Hypothesis/Objective(s): The investigators aim to test whether integrating PE-PC with suvorexant, FDA-approved for the treatment of insomnia, will 1) promote the efficacy of PE-PC in improving sleep and PTSD symptoms in Veterans and military personnel with insomnia and posttraumatic stress disorder (PTSD) with and without mild-to-moderate traumatic brain injury (TBI); and 2) improve psychosocial and physical functioning.
Specific Aims: 1) To examine whether suvorexant facilitates PE-PC, seen as a greater reduction of PTSD symptoms over the course of treatment. 2) To examine whether suvorexant facilitates greater improvement in psychosocial and physical functioning compared to placebo over the course of treatment.
Study Design: The investigators propose an 8-week randomized, double-blind, placebo-controlled Phase IV clinical trial to examine the efficacy of augmenting PE-PC with suvorexant (10-20 mg) for the treatment of PTSD symptoms and improvement of functioning in Veterans with PTSD, insomnia, with and without TBI. The study design (N = 142) will involve repeated measures with two intervention arms, both of which include a standard course of weekly PE-PC therapy: 1) PE-PC+suvorexant (n = 71) compared to 2) PE-PC+placebo (n = 71).
Clinical Impact: This work aligns with the FY24 TBIPHRP CTA Research Level 2, Focus Area to Treat by examining repurposed interventions to improve outcomes of psychological health conditions and/or TBI through treatment and rehabilitation. The proposed intervention could promote sustained functional recovery following insomnia, PTSD, and TBI, as well as increased treatment engagement, retention, and success in those Veterans who would have otherwise not responded to treatment.
Relevance to Military Health: PTSD affects one in four treatment-seeking U.S. Veterans returning from Iraq and Afghanistan and one in 10 VA healthcare users. Sleep disturbance was the most frequently reported symptom in Veterans with PTSD, with the prevalence of insomnia or nonrestorative sleep estimated between 60%-90% and up to 97.4% of combat Veterans with TBI. However, effective and readily available treatments for co-occurring PTSD, insomnia, and TBI are not readily available or successful outside of PTSD specialty clinics, leading to unmet healthcare needs and/or treatment dropout/non-response. The ultimate goal of this work is to improve treatment availability and options for Veterans and military personnel affected by PTSD and TBI. Increased effectiveness of PTSD treatment in Veterans has the potential to: 1) optimize performance; 2) preserve health across the full deployment life cycle; and 3) improve long-term physical, social, and occupational functioning.
200 studies on the registry are indexed under Combat Disorders; 90 are open to participants now.
This study's planned enrollment of 142 is above the median of 72 across 167 interventional studies indexed under Combat Disorders.
Browse Combat Disorders studies →Northern California Institute of Research and Education is the lead sponsor of 12 studies on the registry; 4 are open to participants now.
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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.
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Short tests of memory and thinking, each scored out of 30. Lower scores suggest more difficulty; criteria give a range, either to include people with memory problems or to leave them out.
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
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.
DSM diagnostic criteria
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
MMSE and MoCA
Short tests of memory and thinking, each scored out of 30. Lower scores suggest more difficulty; criteria give a range, either to include people with memory problems or to leave them out.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
CYP3A (CYP3A4) inhibitors and inducers
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
PE-PC with suvorexant
Drug: Suvorexant · Behavioral: Prolonged Exposure Therapy for Primary Care (PE-PC)
PE-PC with placebo
Drug: Placebo · Behavioral: Prolonged Exposure Therapy for Primary Care (PE-PC)
Suvorexant (10-20 mg) taken orally once nightly for 8 weeks, combined with weekly Prolonged Exposure for Primary Care (PE-PC) therapy sessions. Suvorexant is an FDA-approved orexin receptor antagonist indicated for the treatment of insomnia.
A placebo pill taken orally once nightly for 8 weeks, combined with weekly Prolonged Exposure for Primary Care (PE-PC) therapy sessions. The placebo is a look-alike substance that contains no active drug and is used as a comparator to evaluate the efficacy of suvorexant.
Prolonged Exposure for Primary Care (PE-PC) is a briefer version of traditional Prolonged Exposure (PE) therapy, delivered in weekly sessions over 8 weeks. PE-PC is designed to treat PTSD symptoms and related conditions such as insomnia and depression. All study participants will receive PE-PC therapy regardless of their assigned intervention arm (suvorexant or placebo).
Also known as: PE-PC
Change from Baseline in PTSD Symptom Severity as Assessed by the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) at Week 4, Week 8, and 6 Months
The Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) is a 30-item clinician-administered interview measuring the frequency and intensity of PTSD symptoms. Total scores range from 0 to 80, with higher scores indicating greater PTSD symptom severity.
Time frame: Baseline (Week 0), Week 4 (Mid-Treatment), Week 8 (End of Treatment), and 6 months post-treatment; up to 32 weeks.
Change from Baseline in Overall Functioning as Assessed by the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) at Week 4, Week 8, and 6 Months
The World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) is a 36-item self-administered measure assessing functional ability across six domains. Summary scores range from 0 to 100, with higher scores indicating greater disability.
Time frame: Baseline (Week 0), Week 4 (Mid-Treatment), Week 8 (End of Treatment), and 6 months post-treatment; up to 32 weeks
Change from Baseline in Insomnia Severity as Assessed by the Insomnia Severity Index (ISI) at Week 4, Week 8, and 6 Months
The Insomnia Severity Index (ISI) is a 7-item self-report measure of insomnia severity. Total scores range from 0 to 28, with higher scores indicating greater insomnia severity.
Time frame: Baseline (Week 0), Week 4 (Mid-Treatment), Week 8 (End of Treatment), and 6 months post-treatment; up to 32 weeks
Change from Baseline in Objective Sleep Efficiency as Assessed by Wrist Actigraphy at Week 2, Week 4, Week 8, and 6 Months
Objective sleep efficiency will be assessed via wrist actigraphy worn continuously throughout the study. Sleep efficiency is calculated as the percentage of time in bed spent asleep, ranging from 0% to 100%, with higher values indicating better sleep efficiency. Sleep efficiency, sleep maintenance, total sleep time, and wake after sleep onset will be examined as secondary measures of sleep.
Time frame: Baseline (Week 0), Week 4 (Mid-Treatment), Week 8 (End of Treatment), and 6 months post-treatment; up to 32 weeks
Change from Baseline in Subjective Sleep Efficiency as Assessed by Daily Sleep Diary at Week 2, Week 4, Week 8, and 6 Months
Subjective sleep efficiency will be assessed via daily self-reported sleep diary. Sleep efficiency is calculated as the percentage of time in bed spent asleep, ranging from 0% to 100%, with higher values indicating better sleep efficiency.
Time frame: Baseline (Week 0), Week 4 (Mid-Treatment), Week 8 (End of Treatment), and 6 months post-treatment; up to 32 weeks
Change from Baseline in Psychosocial Functioning as Assessed by the Brief Inventory of Psychosocial Functioning (B-IPF) at Week 4, Week 8, and 6 Months
The B-IPF (Brief Inventory of Psychosocial Functioning) is a 7-item self-report measure assessing PTSD-related functional impairment in the past 30 days across seven functional domains, including romantic relationships, family relationships, work, friendships and socializing, parenting, education, and self-care.
Time frame: Baseline (Week 0), Week 4 (Mid-Treatment), Week 8 (End of Treatment), and 6 months post-treatment; up to 32 weeks
Change from Baseline in Quality of Life as Assessed by the World Health Organization Quality of Life Assessment Brief Version (WHOQOL-BREF) at Week 4, Week 8, and 6 Months
The World Health Organization Quality of Life Assessment Brief Version (WHOQOL-BREF) is a 26-item instrument assessing quality of life across four domains: physical health, psychological health, social relationships, and environmental health. Items are scored 1-5 and transformed to a standardized scale of 0-100, with higher scores indicating better quality of life.
Time frame: Baseline (Week 0), Week 4 (Mid-Treatment), Week 8 (End of Treatment), and 6 months post-treatment; up to 32 weeks
Change from Baseline in Engagement in Meaningful Activities as Assessed by the Engagement in Meaningful Activities Survey (EMAS) at Week 4, Week 8, and 6 Months
The Engagement in Meaningful Activities Survey (EMAS) is a 12-item scale assessing meaningful activity participation. Total scores range from 12 to 48, with higher scores indicating greater engagement in meaningful activities.
Time frame: Baseline (Week 0), Week 4 (Mid-Treatment), Week 8 (End of Treatment), and 6 months post-treatment; up to 32 weeks
Plan to share: Yes — Individual participant data (IPD) that underlie the results reported in publications will be shared, including data on primary and secondary outcome measures (PTSD symptom severity, psychosocial and physical functioning, sleep outcomes, and quality of life). Data will be de-identified prior to sharing to protect participant confidentiality. Demographic and clinical characteristics used to describe the study sample will also be made available.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Analytic code
Time frame: De-identified IPD and supporting information will be available beginning 12 months after the publication of primary study results and will remain available for a minimum of 5 years following the end of the study.
Access criteria: De-identified IPD will be available to researchers who provide a methodologically sound proposal and agree to the terms of a data use agreement. Requests for data access should be submitted to the principal investigator. Data will be shared in a secure manner consistent with applicable federal regulations and institutional policies governing research data sharing.
Start is estimated for Sep 2026; primary completion for Mar 2029, 30 months later.
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This study is not yet recruiting, as verified in Jun 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Suvorexant
Northern California Institute of Research and Education