Posttraumatic Stress DisorderPhase 3PREDICTNCT03539614
Predicting Responses to PTSD Treatment With Iris and Cardiovascular Tests
A Phase 3 study testing Prazosin in people with Posttraumatic Stress Disorder, run by VA Office of Research and Development at 1 site in United States.
Trial summary
Post-traumatic stress disorder (PTSD) affects many individuals who experience a traumatic event. There are a variety of treatment options for PTSD, including psychotherapy (talk therapy) options, as well as medications, such as the drug prazosin. Read more about this study
- Who is it for?
- Ages 21 to 75 years
- Conditions the study is for
- Posttraumatic Stress Disorder
- What is being tested?
- Prazosin
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 87 participants
- Where
- 1 siteUnited States
- Study dates
- 4 Jun 2018to 31 Dec 2026
- Phase
- Phase 3
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 21 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Veteran of the U.S. Armed Forces
- Current diagnosis of PTSD (as documented in clinical chart and/or per participant report; a rule out diagnosis from a VA provider accompanied by a referral to the VA PTSD Outpatient Clinic (POC) will also be considered sufficient for inclusion)
- Woman of childbearing potential must agree to abstain from sexual relations that could result in pregnancy or use an effective method of birth control acceptable to both participant and study clinician during the study. Men are not required to use contraception during the study.
Who cannot join
- Psychiatric:
- Any known diagnosis of a primary psychotic or major neurocognitive disorder, including schizophrenia, brief psychotic disorder, or Alzheimer's or other dementia, as well as bipolar type I
- Severe psychiatric instability or severe situational life crises, including evidence of being actively suicidal or homicidal, or any behavior which poses an immediate danger to participant or others.
- Note: Nonsuicidal depression comorbid with PTSD will not be exclusionary. Participants may continue in any concurrent psychotherapy or pharmacotherapy in which they are participating, other than pharmacotherapeutic agents specifically listed above. Participants with active suicidal ideation or with depression severe enough to require psychiatric hospitalization will be excluded.
- Medical:
- Significant bilateral visual loss (would preclude performing the PLR measurements)
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- Current pregnancy or lactation
- Allergy or previous adverse reaction to prazosin or other alpha-1 antagonist
- Acute or unstable chronic medical illness, including unstable angina, recent myocardial infarction (within 6 months), congestive heart failure, preexisting hypotension (systolic <110) or orthostatic hypotension (systolic drop > 20mmHg after two minutes standing or any drop accompanied by dizziness); autoimmune disorders; insulin-dependent diabetes
- Chronic renal or hepatic failure, acute pancreatitis, Meniere's disease, benign positional vertigo, or narcolepsy
- Medication / treatment:
- Any use within the 7 days prior to baseline of prazosin, doxazosin, clonidine, guanfacine, trazodone, or nonbenzodiazepine hypnotics, and/or unwillingness to avoid these medications for the duration of the study
- Use of avanafil (Stendra), sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra) will be not be permitted during the study dose titration period because of increased risk of hypotension in combination with alpha-1 blockers, but will be allowed at 1/2 the usual starting dose following dose titration
- Current use of nitrates, or of alternative medications or supplements with significant vasodilatory properties (e.g., nitrate containing supplements)
- Participants may also be excluded at the discretion of PI or study clinicians if they appear to be unsuitable for this research study for a reason not detailed here.
Trial locations and contacts
1 site in 1 country.
United States1 site
VA Puget Sound Health Care System Seattle Division, Seattle, WA
Seattle, Washington, 98108-1532
About this study
Official title: Noradrenergic Biomarkers in PTSD: Precision Medicine & Mechanisms
Post-traumatic stress disorder (PTSD) affects many individuals who experience a traumatic event. There are a variety of treatment options for PTSD, including psychotherapy (talk therapy) options, as well as medications, such as the drug prazosin. Each of the treatment options available is effective at significantly reducing the symptoms of PTSD in some, but not all, individuals with PTSD. However, investigators are not yet able to predict in advance who is likely to respond to which of the available treatments. Neither are the investigators able to explain what changes in the brain after exposure to a traumatic stressors, and why it results in persistent symptoms of PTSD for some people, but not for others.
In this study, the investigators are testing two things: First, is testing whether two simple, easy tests of how an individual's blood pressure changes with standing and how an individual's eye reacts to a pulse of light may be able to predict whether that person is likely to respond to the medication prazosin for PTSD. Second, is testing whether those who have been exposed to a traumatic stress show differences in how their body regulates the response to the stress-signal noradrenaline.
Read the detailed description
In this study, individuals will undergo an assessment that includes taking a history of their previous exposure to traumatic events, an assessment of current mental health symptoms including those associated with PTSD, and an assessment of physiologic measures, such as blood pressure and pupillary responses to light. For individuals who have current symptoms of PTSD and for whom use of the medication prazosin is a reasonable and safe option, a second phase of the study will be offered. In this second phase, how the individual's PTSD symptoms change when taking prazosin will be assessed. In addition, to test whether any changes are related to the prazosin itself or are part of a placebo effect, the individual will be randomly assigned to periods where he or she is taking a pill that looks like prazosin but is actual placebo (a pill with no active ingredient), and periods where he or she is taking a pill that looks the same but this time is actual prazosin.
Of note, there is also an additional observational portion of the protocol that is not a direct part of the interventional trial described here, but data from which will be used to help to interpret the data from the interventional trial; because reporting of study results depends on both portiosn, the study completion date estimates/reports will reflect when both the interventional and observational trial components are complete.
- Conditions
- Posttraumatic Stress Disorder
- Being tested
- Prazosin, Placebo
- Keywords
- Prazosin, Nightmares, N-of-1
- Medical subject headings
- Stress Disorders, Post-Traumatic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PrazosinDrug
Also called Minipress
This is an antagonist of the alpha1 receptor for noradrenaline. It is FDA approved for the treatment of hypertension, and has also been used for benign prostatic hypertrophy (BPH). Most recently, it has been found to be helpful for symptoms of PTSD in some but not all participants.
PlaceboDrug
This is a capsule containing an inert substance, in order to provide blinding to participants and study staff of when participants are on active medication and when they are not during the later portions of the trial.
| Study group | Role | What they receive |
|---|---|---|
| Open label, blinded discontinuation, prazosin, placebo | Experimental | All participants in this study will begin with 8 weeks of active treatment (prazosin), followed by a 4 week "blinded discontinuation" block where they will take a capsule that will start out as active treatment (prazosin), but will at some point change to placebo. Following these phases of the study, participants will be randomized to two arms. In this first arm, participants will spend 4 weeks on active treatment (prazosin), followed by 4 weeks on placebo. Receives: Drug: Prazosin; Drug: Placebo |
| Open label, blinded discontinuation, placebo, prazosin | Experimental | All participants in this study will begin with 8 weeks of active treatment (prazosin), followed by a 4 week "blinded discontinuation" block where they will take a capsule that will start out as active treatment (prazosin), but will at some point change to placebo. Following these phases of the study, participants will be randomized to two arms. In this second arm, participants will spend 4 weeks on placebo, followed by 4 weeks on active treatment (prazosin). Receives: Drug: Prazosin; Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in total PTSD Checklist for DSM 5 (PCL5) score
The PTSD Checklist for Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM 5) is a self-reported rating scale where an individual rates the severity of each symptom of PTSD on a Likert scale. The ratings on individual items are summed to create a total score, which ranges from 0 to 80, with higher scores indicating more symptoms. The relationship between changes in participants' total PCL scores at different time points and prazosin exposure - and whether this relationship is moderated by baseline biomarker values - will be analyzed using a linear mixed effects model.
Measured: The PCL5 total score is assessed at baseline, during each stage of the study, and at the endpoint of the study. Thus, measurements will be scheduled to occur at the following time points, relative to the baseline visit: 0, 4, 8, 9-12, 16, and 20 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 May 2018
- Study start4 Jun 2018
- Primary completion1 Jan 2026
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Posttraumatic Stress DisorderStudies of the same condition, open and under way.
- More trials run by VA Office of Research and DevelopmentThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- This study is a modified cross-over study, also called an aggregated N-of-1 study. Each participant who meets criteria for participation in and completes the treatment portion of the study will spend time on open-label prazosin, blinded prazosin, and placebo.
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Outcomes assessor
- Enrolment
- 87 participants (actual)
Sponsor and investigators
- Lead sponsor
- VA Office of Research and Development
- Sponsor type
- US federal agency
- Responsible party
- Sponsor
- Investigators
- Rebecca C. Hendrickson, MD PhD, Principal investigator, VA Puget Sound Health Care System Seattle Division, Seattle, WA
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03539614
- Sponsor's protocol ID
- MHBB-003-17F
- Other IDs
- 1IK2CX001774-01
- Acronym
- PREDICT
- Status last verified
- Aug 2026
- First submitted
- 2 May 2018
- Last updated
- 14 Aug 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 14 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Noradrenergic Biomarkers in PTSD: Precision Medicine & Mechanisms
- ClinicalTrials.gov ID
- NCT03539614
- Acronym / sponsor ID
- PREDICT / MHBB-003-17F
- Conditions
- Posttraumatic Stress Disorder
- Keywords
- Prazosin, Nightmares, N-of-1
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 87 participants (actual)
- Lead sponsor
- VA Office of Research and DevelopmentUS federal agency
- Study start
- 4 Jun 2018 (actual)
- Primary completion
- 1 Jan 2026 (actual)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 29 May 2018 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Post-traumatic stress disorder (PTSD) affects many individuals who experience a traumatic event. There are a variety of treatment options for PTSD, including psychotherapy (talk therapy) options, as well as medications, such as the drug prazosin. Each of the treatment options available is effective at significantly reducing the symptoms of PTSD in some, but not all, individuals with PTSD. However, investigators are not yet able to predict in advance who is likely to respond to which of the available treatments. Neither are the investigators able to explain what changes in the brain after exposure to a traumatic stressors, and why it results in persistent symptoms of PTSD for some people, but not for others.
In this study, the investigators are testing two things: First, is testing whether two simple, easy tests of how an individual's blood pressure changes with standing and how an individual's eye reacts to a pulse of light may be able to predict whether that person is likely to respond to the medication prazosin for PTSD. Second, is testing whether those who have been exposed to a traumatic stress show differences in how their body regulates the response to the stress-signal noradrenaline.
Detailed description
In this study, individuals will undergo an assessment that includes taking a history of their previous exposure to traumatic events, an assessment of current mental health symptoms including those associated with PTSD, and an assessment of physiologic measures, such as blood pressure and pupillary responses to light. For individuals who have current symptoms of PTSD and for whom use of the medication prazosin is a reasonable and safe option, a second phase of the study will be offered. In this second phase, how the individual's PTSD symptoms change when taking prazosin will be assessed. In addition, to test whether any changes are related to the prazosin itself or are part of a placebo effect, the individual will be randomly assigned to periods where he or she is taking a pill that looks like prazosin but is actual placebo (a pill with no active ingredient), and periods where he or she is taking a pill that looks the same but this time is actual prazosin.
Of note, there is also an additional observational portion of the protocol that is not a direct part of the interventional trial described here, but data from which will be used to help to interpret the data from the interventional trial; because reporting of study results depends on both portiosn, the study completion date estimates/reports will reflect when both the interventional and observational trial components are complete.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, care provider, outcomes assessor)
- Number of arms
- 2
- Model description
- This study is a modified cross-over study, also called an aggregated N-of-1 study. Each participant who meets criteria for participation in and completes the treatment portion of the study will spend time on open-label prazosin, blinded prazosin, and placebo.
| Arm | Type | Receives |
|---|---|---|
| Open label, blinded discontinuation, prazosin, placebo | Experimental | Drug: Prazosin, Drug: PlaceboAll participants in this study will begin with 8 weeks of active treatment (prazosin), followed by a 4 week "blinded discontinuation" block where they will take a capsule that will start out as active treatment (prazosin), but will at some point change to placebo. Following these phases of the study, participants will be randomized to two arms. In this first arm, participants will spend 4 weeks on active treatment (prazosin), followed by 4 weeks on placebo. |
| Open label, blinded discontinuation, placebo, prazosin | Experimental | Drug: Prazosin, Drug: PlaceboAll participants in this study will begin with 8 weeks of active treatment (prazosin), followed by a 4 week "blinded discontinuation" block where they will take a capsule that will start out as active treatment (prazosin), but will at some point change to placebo. Following these phases of the study, participants will be randomized to two arms. In this second arm, participants will spend 4 weeks on placebo, followed by 4 weeks on active treatment (prazosin). |
Who may qualify
- Ages
- 21 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Veteran of the U.S. Armed Forces
- Current diagnosis of PTSD (as documented in clinical chart and/or per participant report; a rule out diagnosis from a VA provider accompanied by a referral to the VA PTSD Outpatient Clinic (POC) will also be considered sufficient for inclusion)
- Woman of childbearing potential must agree to abstain from sexual relations that could result in pregnancy or use an effective method of birth control acceptable to both participant and study clinician during the study. Men are not required to use contraception during the study.
Key exclusion criteria (15 listed)
- Psychiatric:
- Medical:
- Medication / treatment:
- Participants may also be excluded at the discretion of PI or study clinicians if they appear to be unsuitable for this research study for a reason not detailed here.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PrazosinAlso: MinipressThis is an antagonist of the alpha1 receptor for noradrenaline. It is FDA approved for the treatment of hypertension, and has also been used for benign prostatic hypertrophy (BPH). Most recently, it has been found to be helpful for symptoms of PTSD in some but not all participants. | Drug | Open label, blinded discontinuation, placebo, prazosin, Open label, blinded discontinuation, prazosin, placebo |
| PlaceboThis is a capsule containing an inert substance, in order to provide blinding to participants and study staff of when participants are on active medication and when they are not during the later portions of the trial. | Drug | Open label, blinded discontinuation, placebo, prazosin, Open label, blinded discontinuation, prazosin, placebo |
Primary outcome
Change in total PTSD Checklist for DSM 5 (PCL5) score
Time frame: The PCL5 total score is assessed at baseline, during each stage of the study, and at the endpoint of the study. Thus, measurements will be scheduled to occur at the following time points, relative to the baseline visit: 0, 4, 8, 9-12, 16, and 20 weeks
The PTSD Checklist for Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM 5) is a self-reported rating scale where an individual rates the severity of each symptom of PTSD on a Likert scale. The ratings on individual items are summed to create a total score, which ranges from 0 to 80, with higher scores indicating more symptoms. The relationship between changes in participants' total PCL scores at different time points and prazosin exposure - and whether this relationship is moderated by baseline biomarker values - will be analyzed using a linear mixed effects model.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Aug 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Rebecca C. Hendrickson, MD PhD principal investigator
VA Puget Sound Health Care System Seattle Division, Seattle, WA
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Prazosin in people with Posttraumatic Stress Disorder, run by VA Office of Research and Development at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 15 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 14 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in total PTSD Checklist for DSM 5 (PCL5) score (time frame: The PCL5 total score is assessed at baseline, during each stage of the study, and at the endpoint of the study. Thus, measurements will be scheduled to occur at the following time points, relative to the baseline visit: 0, 4, 8, 9-12, 16, and 20 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Aug 2026.