Suvorexant and Sleep's Benefits to Therapeutic Exposure for Posttraumatic Stress Disorder

  • End date
    Jul 31, 2021
  • participants needed
  • sponsor
    Howard University
Updated on 29 November 2020
Imani Brown, MPH
Primary Contact
Clinical Research Unit; Howard University Hospital (5.2 mi away) Contact


The purpose of this study is to examine effects of blocking the orexin system with suvorexant after exposure-based intervention for posttraumatic stress disorder (PTSD) on sleep, PTSD symptoms, and intersession habituation.


Cognitive behavioral therapies (CBT) that include exposure to trauma memories are considered first line treatments for PTSD. However, approximately 1/3 of patients who complete CBT for PTSD do not achieve remission, and hyperarousal symptoms including sleep disturbances are less responsive to CBT than other PTSD symptoms. Despite these limitations, CBT outcomes are generally superior to outcomes of pharmacotherapy. It is, therefore, imperative to identify strategies to improve effectiveness of treatments for PTSD, particularly hyperarousal symptoms.

Disturbed sleep is common in PTSD. Studies of PTSD and anxiety and mood disorders have shown that impaired sleep before psychotherapy predicted less favorable responses. Sleep has been implicated in learning processes that are a key to adaptive processing of trauma memories such as extinction learning and generalization of extinction. Our recent PTSD study showed that preserved slow-wave sleep (SWS), less increase in rapid-eye-movement (REM) density, and reduced wake after sleep onset (WASO) during sleep following an evening session of written narrative exposure (WNE: writing about one's traumatic experience) was associated with greater PTSD symptom reduction. These findings suggest that increased nocturnal arousal compromises sleep's benefits to emotional processing of trauma memories. Identifying strategies to reduce nocturnal arousal and promote sleep characteristics associated with emotional adaptation could enhance PTSD treatment outcomes.

Orexins are neuropeptides implicated in regulating both sleep/wakefulness and emotional behaviors, including anxiety. Inhibiting the orexin system promoted slow-wave patterns and reduced wake in animal models. The first orexin receptor antagonist (suvorexant) was recently approved for treatment of insomnia. Suvorexant reduced WASO and latency to persistent sleep and increased SWS and REM sleep in humans with insomnia. In addition, administrations of orexin-A increased anxiety-like behaviors in rodents, and administrations of an orexin receptor-1 antagonist to mice facilitated extinction of conditioned fear, an animal model of recovery from PTSD and anxiety disorders.

Objective: To examine effects of blocking the orexin system with suvorexant after WNE on sleep, PTSD symptoms, and intersession habituation.

The investigators will utilize the WNE paradigm in which participants with PTSD write about their traumatic experiences in the evening and morning sessions with intervening sleep. Suvorexant or placebo will be administered after the evening WNE, and sleep will be recorded.

The investigators hypothesize that 1) Suvorexant will promote the sleep characteristics that have been associated with more favorable treatment outcomes and emotional adaptation (e.g., increased SWS and REM sleep, reduced WASO) compared with placebo; 2) Participants given suvorexant will have greater PTSD symptom reduction and intersession habituation indexed by reduction of maximum pulse rate compared with participants given placebo; and 3) The greater PTSD symptom reduction and intersession habituation in the suvorexant group will be accounted for by effects of the medication on sleep.

Treatment Placebo, Suvorexant
Clinical Study IdentifierNCT02849548
SponsorHoward University
Last Modified on29 November 2020

Adding a note
adding personal notes guide

Select a piece of text and start making personal notes.


Yes No Not Sure

Inclusion Criteria

Is your age greater than or equal to 18 yrs?
Gender: Male or Female
Do you have any of these conditions: Post-Traumatic Stress Disorders or Post-Traumatic Stress Disorder?
Do you have any of these conditions: PTSD or Post-Traumatic Stress Disorder or Post-Traumatic Stress Disorders?
Do you have any of these conditions: PTSD or Post-Traumatic Stress Disorders or Post-Traumatic Stress Disorder?
Adult men and women (age 18 or older) who meet the Diagnostic and Statistical Manual of Mental Disorders - Fifth Edition (DSM-5) criteria for PTSD

Exclusion Criteria

Medical or psychiatric conditions that require consistent use of medication that affects sleep or psychiatric symptoms, except for hormonal contraceptives
Any persistent medical condition that affects sleep
Inability to remember most details of the index event
Diagnosis of a sleep disorder other than insomnia including polysomnography findings of apnea/hypopnea index > 10/hour
Consumption of more caffeine than 5 cups of coffee/day equivalent
Smoking > 20 cigarettes/day
Habitual bedtimes after 3AM, habitual rise times after 10AM, or average napping > 2 hour/day in a given week
Moderate or severe alcohol use disorder within the past 6 months or moderate or severe drug use disorder within the past year
Positive urine toxicology for illicit drugs including cannabis
A history of psychotic disorders or bipolar disorder
Current depression with history of recurrent depression that precedes exposure to a traumatic event
Suicidal ideation with intent to act or with specific plan and intent in the past 6 months [Type 4 - 5 ideation on the Columbia Suicide Severity Rating Scale (C-SSRS)] or history of a suicide attempt
Completion of exposure-based therapy targeting the index trauma
Pregnancy or breast feeding
Known sensitivity or allergy to an orexin receptor antagonist
Limited ability to read or write English
Clear my responses

How to participate?

Step 1 Connect with a site
What happens next?
  • You can expect the study team to contact you via email or phone in the next few days.
  • Sign up as volunteer to help accelerate the development of new treatments and to get notified about similar trials.

You are contacting

Investigator Avatar

Primary Contact


Phone Email

Please verify that you are not a bot.
Step 2 Get screened

Additional screening procedures may be conducted by the study team before you can be confirmed eligible to participate.

Learn more
Step 3 Enroll in the clinical study

If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.

Learn more
Step 4 Get your study results

Complete your scheduled study participation activities and then you are done. You may receive summary of study results if provided by the sponsor.

Learn more

Similar trials to consider


Browse trials for

Not finding what you're looking for?

Every year hundreds of thousands of volunteers step forward to participate in research. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.

Sign up as volunteer


user name

Annotated by • 



Reply by • Private

Lorem ipsum dolor sit amet consectetur, adipisicing elit. Ipsa vel nobis alias. Quae eveniet velit voluptate quo doloribus maxime et dicta in sequi, corporis quod. Ea, dolor eius? Dolore, vel!

  The passcode will expire in None.

No made yet