NCT03642028 · VA Office of Research and Development
Suvorexant: A Dual Orexin Receptor Antagonist for Treating Sleep Disturbance in Posttraumatic Stress
What this study is about
Post-traumatic stress disorder (PTSD) is a common consequence of combat that can result in trauma-related hyperarousal and sleep disturbances. Poor sleep, one of the most common complaints in Veterans with PTSD, can be distressing, impair concentration and memory, and contribute to physical health conditions, such as metabolic syndrome, inflammation, and cardiovascular disease.
View original scientific description
Post-traumatic stress disorder (PTSD) is a common consequence of combat that can result in trauma-related hyperarousal and sleep disturbances. Poor sleep, one of the most common complaints in Veterans with PTSD, can be distressing, impair concentration and memory, and contribute to physical health conditions, such as metabolic syndrome, inflammation, and cardiovascular disease. The orexin neuropeptide system underlies both sleep and stress reactivity.
Interventions
DRUG
Suvorexant
Suvorexant, a dual orexin receptor antagonist, is the first in a new class of drugs with great promise of addressing insomnia in Veterans with PTSD. Suvorexant targets the orexin neuropeptide system and has been shown to be highly successful in treating insomnia.
OTHER
Placebo
Visibly matched, equally weighted placebo tablets. In addition to matching in appearance and weight, they will have identical packaging and labeling as randomized, blinded study medication.
Primary outcome measures
Insomnia Severity Index (ISI)
Time frame: Change from baseline to week 12
The ISI is a specific index of perceived insomnia severity. Areas assessed include problems with sleep onset, sleep maintenance, and early morning awakening; dissatisfaction with sleep; interference with daily functioning; impact on quality of life; and worry about sleep problems.
Clinician Administered PTSD Scale for DSM-5 (CAPS-5)
Time frame: Change from baseline to week 12
The CAPS-5 is a 30-item interview that is the gold standard assessment for PTSD. The CAPS-5 provides a dimensional and categorical measure of PTSD, and incorporates frequency and intensity of symptoms into a single severity score. The CAPS-5 will determine a threshold for PTSD severity (past week) at baseline (excluding change in item #20 falling and staying asleep). Possible scores range from 0 to 80. All trained and certified CAPS-raters will function independently and will not be involved in recruitment, study coordination, or evaluation of side effects.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Men and Women, age range of 18 to 75, with a history of US military service, capable of reading and understanding English, and able to provide written informed consent
- Criterion A event meets DSM-5 criteria
- PTSD symptoms \>3 months duration as indexed by a CAPS-5 12 and a partial PTSD diagnosis at screening
- Insomnia indicated by an ISI score \> 14
- Subjects on non-
Exclusion criteria
- ary medications must be on a stable dose for at least 4 weeks prior to randomization, which includes the Selective Serotonin Reuptake Inhibitors (SSRIs) e.g.:
- Fluvoxamine
- Escitalopram
- Serotonin-norepinephrine reuptake inhibitors (SNRIs), e.g.:
- Desvenlafaxine
- Levomilnacipran
- Venlafaxine
- For subjects who are in psychotherapy, treatment must be stable for 6 weeks
- Women of child-bearing potential must not be pregnant or have plans for pregnancy or breastfeeding during the study and must use
Where
- Long Beach, California
- San Francisco, California
- Salisbury, North Carolina
- Charleston, South Carolina
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 18, 2025 · Source of record for eligibility and locations