Gulf War IllnessNCT05375812
NIH Investigative Deep Phenotyping Study of Gulf War Veteran Health (Project NIH IN-DEPTH)
An observational study of Gulf War Illness, run by National Institute of Neurological Disorders and Stroke (NINDS) at 1 site in United States.
Trial summary
Background: Gulf War illness (GWI) affects up to 210,000 U.S. veterans who served in the Middle East during the Gulf War in 1990-1991. Symptoms include fatigue, muscle and joint pain, forgetfulness, headaches, rashes, and sleep disturbances. Routine exams cannot determine the cause of GWI. Read more about this study
- Who is it for?
- Ages 48 to 70 yearsHealthy volunteers can take part
- Conditions the study is for
- Gulf War Illness
- How many people
- 85 participants
- Where
- 1 siteUnited States
- Study dates
- 16 Apr 2023to 31 Dec 2030
- Phase
- Observational
- 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 48 to 70 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: A Target of 50 GWI participants and 25 Healthy volunteer controls will be selected.
Who may be able to join
- Ability to provide informed consent
- Stated willingness to comply with all study procedures and availability for the duration of the study
- Age 48-70 at time of enrollment into VA IN-DEPTH Study
- Veterans who were deployed to Gulf Region ODS/S between August 1990 - June 1991.
- Self-reported completion of at least the seventh grade of school.
- Fluency in speaking, reading, and understanding English.
- Underwent screening as part of the VA IN-DEPTH study and were unanimously determined to be eligible by the IN-DEPTH Adjudication Committee.
- Agree not to smoke in the 4 hours prior to CPET procedure
Who cannot join
- Current or past psychotic disorder including depression with psychosis, bipolar disorder with psychotic symptoms and schizophrenia
- Current DSM-5-defined major depression disorder, generalized anxiety disorder, posttraumatic stress disorder, panic disorder, or obsessive-compulsive disorder unless managed for more than six months with a stable treatment regimen
- Current or past substance use disorder within last five years as diagnosed on the Structured Clinical Interview for DSM-5 (SCID-5). Prior or prescription marijuana use within the past five years will not be an exclusion.
- Current suicidal ideation
- History of head injury leading to moderate or severe traumatic brain injury, as detailed by loss of consciousness for greater than 30 minutes, a Glasgow Coma Score of 12 or less at the time of injury, post-traumatic amnesia greater than one day, or brain-scan changes related to a head injury. Persons having a history of mild TBI (mTBI) will not be excluded.
- Women who are pregnant, breastfeeding, or are within one-year post-partum.
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- Current or previous malignancy. A history of malignancy that has fully resolved with surgical resection only (e.g. no chemotherapy, radiation therapy, or immunotherapy) will be allowed.
- Current systemic immunologic disorders (e.g. Type 1 diabetes, rheumatoid arthritis). Local immunological disorder (e.g. atopic dermatitis, stable autoimmune thyroid disease) and allergic disorders will be allowed.
- Current or previous long-term immune suppressive therapy. Systemic steroid use, even short-term, must not have been used within the month prior to enrollment
- Any medical condition that would make the study procedures risky for the participant (e.g. congestive heart failure, coronary artery disease, chronic obstructive pulmonary disease, severe osteoarthritis, exercise-induced angina and poorly controlled asthma).
- Active participation in a clinical protocol (e.g. anti-inflammatory drug intervention study) which includes an intervention that may affect the results of the current study.
- Inability to perform the bicycling exercise task. (e.g. coronary artery disease, not having a lower limb, disabling stroke)
- Not willing to allow for research data and samples to be shared broadly with other researchers.
- Symptom severity that makes it impossible for the volunteer to travel to NIH for extended inpatient evaluation
- Use of medications with a high-risk for withdrawal-related complications (i.e. long-acting opiates or benzodiazepines).
- Additional Exclusion criteria for participants undergoing TMS:
- Pacemaker, implanted pump, stimulator, cochlear implant or metal objects inside the eye or skull.
- Participants with unconfirmed metal may have further evaluation to rule out metal in the eye or skull.
- Participants without metal after evaluation may proceed to TMS.
- A personal history of seizure disorder
- Additional Exclusion criteria for participants undergoing MRI:
- Metal in the body which would make having an MRI scan unsafe, such as pacemakers, stimulators, pumps, aneurysm clips, metallic prostheses, artificial heart valves, cochlear implants or shrapnel fragments, or having a history of being a welder or metal worker, since small metal fragments may be in the eye. Participants with unconfirmed metal may have further evaluation to rule out metal in the eye
- or skull. Participants without metal after evaluation may proceed to MRI.
- Substantial claustrophobia
- Inability to lie on back for up to 2 hours
- Additional Exclusion criteria for Healthy Veteran Controls:
- Meets modified Kansas criteria for GWI.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
National Institutes of Health Clinical Center
Bethesda, Maryland, 20892
For more information at the NIH Clinical Center contact Office of Patient Recruitment (OPR), 800-411-1222 ext. TTY dial 711, ccopr@nih.gov
About this study
Background:
Gulf War illness (GWI) affects up to 210,000 U.S. veterans who served in the Middle East during the Gulf War in 1990-1991. Symptoms include fatigue, muscle and joint pain, forgetfulness, headaches, rashes, and sleep disturbances. Routine exams cannot determine the cause of GWI. Researchers need more information to understand this disease.
Read more
Objective:
This natural history study will look for differences in Gulf War veterans who experienced GWI and those who did not.
Eligibility:
Gulf War veterans with GWI. Healthy Gulf War veterans who do not have GWI are also needed.
Design:
Participants will stay in the NIH Clinical Center as an inpatient for 2 weeks. They will undergo many tests.
Blood will be drawn many times throughout the study. Participants will also give urine, saliva, and stool samples.
Scans to measure the brain, leg muscles, bone density and body mass will be done.
They will have an exercise stress test and muscle strength tests.
They will have a sleep study. They will have tests to look at how well the brain, heart and lungs are working.
Participants will sleep in a specialized room that measures the amount of oxygen they use and the carbon dioxide they produce on four consecutive nights.
A sample of fluid will be collected from inside the spine.
Participants will take many surveys. Some will ask about their activities. Some will be about emotional and mental health. Some will be about thinking, memory, and behavior.
Optional tests include other imaging scans and testing the autonomic nervous system. Samples of skin and muscle may be taken.
After discharge, participants will wear activity monitors for 14 days. They will keep a diary of their symptoms, including fatigue, pain, and sleep, while wearing the monitors.
Read the detailed description
Study Description:
This protocol is part of a joint collaboration with the Veterans' Administration (VA) known as (Project IN-DEPTH). The Veterans' Administration protocol will recruit and identify participants for the NIH study, and maintain a repository of data and samples through a VA protocol (VA IN-DEPTH). The NIH protocol (NIH IN-DEPTH) will conduct deep phenotyping evaluations on study participants.
Gulf War Illness (GWI) and Gulf War Chronic Multi-Symptom Illness are names that have been used to describe a disorder of fatigue, muscle and joint pain, loss of concentration, forgetfulness, headache, respiratory complaints, rashes, sleep disturbances, and/or gastrointestinal distress. The purpose of this study is to learn more about GWI from veterans deployed in Persian Gulf during the first Gulf War.
In this study, two groups of veterans who were deployed to the Persian Gulf war between August 1990 and June 1991 will be enrolled: those who are healthy veteran controls (HVC) and those with GWI. Participants will have an inpatient study visit typically lasting 14 days to explore clinical and biological phenotypes through evaluations via questionnaires, medical procedures such as exercise testing, history and physical examination, and laboratory evaluation of samples.
This protocol is a "sister study" to the NIH protocol 16-N-0058: Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome (ME/CFS) at NIH. The symptoms of GWI and ME/CFS are very similar and much may be learned about each disorder through comparison. For this reason, the two studies will use similar methods. Participants in 16-N-0058 had previously consented to sharing of data, therefore datasets from this NIH IN-DEPTH protocol and 16-N-0058 will be shared and combined to perform several of the planned exploratory analyses.
This study will take place at the National Institutes of Health (NIH) Clinical Center in Bethesda, Maryland.
Objectives: Primary Objective:
To explore and compare the clinical and biological phenotypes of veterans with GWI and healthy veteran controls (HVC) at baseline.
Exploratory Objectives:
To explore the pathophysiology of fatigue and GWI symptom flares. Fatigue will be explored using tasks designed to create muscular and cognitive fatigue. GWI symptom flares will be explored using an exercise stress test and measuring the symptomatic and biological changes.
To compare the clinical and biological phenotypes between GWI, HVC, ME/CFS, and healthy volunteers.
Endpoints: Outcome measures
The primary purpose of this protocol is to perform exploratory analysis of collected data and samples for the generation of new hypotheses regarding GWI. The types of analyses to be performed will be wide ranging. Planned areas of focus may include:
- Characterization of the immune system and inflammatory signaling.
- Characterization of the pattern of microbiome.
- Characterization of bioenergetics, autonomic, and metabolic function.
- Characterization of neurocognition.
- Conditions
- Gulf War Illness
- Keywords
- Veteran, Gwi (Gulf War Illness), Natural History
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| GWI | Gulf War Veterans | |
| HVC | Healthy Volunteer Controls |
What is being measured
The primary outcome is the main question the study is designed to answer.
To explore and compare the clinical and biological phenotypes of veterans with GWI and healthy veteran controls (HVC) at baseline.
Evaluate a number of clinical and biological measures.
Measured: one time visit
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 May 2022
- Study start16 Apr 2023
- Primary completion31 Dec 2030 (estimated)
- Study completion31 Dec 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Gulf War IllnessStudies of the same condition, open and under way.
- More trials run by National Institute of Neurological Disorders and Stroke (NINDS)The 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
- Observational
- Observational model
- Other
- Time perspective
- Cross-sectional
- Enrolment
- 85 participants (estimated)
Sponsor and investigators
- Sponsor type
- US National Institutes of Health
- Responsible party
- Sponsor
- Investigators
- Brian T Walitt, M.D., Principal investigator, National Institute of Neurological Disorders and Stroke (NINDS)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05375812
- Sponsor's protocol ID
- 10000051
- Other IDs
- 000051-N
- Status last verified
- 30 Oct 2026
- First submitted
- 13 May 2022
- Last updated
- 3 Nov 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 3 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- NIH Investigative Deep Phenotyping Study of Gulf War Veteran Health (Project NIH IN-DEPTH)
- ClinicalTrials.gov ID
- NCT05375812
- Acronym / sponsor ID
- 10000051
- Conditions
- Gulf War Illness
- Keywords
- Veteran, Gwi (Gulf War Illness), Natural History
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 85 participants (estimated)
- Lead sponsor
- National Institute of Neurological Disorders and Stroke (NINDS)US National Institutes of Health
- Study start
- 16 Apr 2023 (actual)
- Primary completion
- 31 Dec 2030 (estimated)
- Study completion
- 31 Dec 2030 (estimated)
- First posted
- 17 May 2022 (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.
Background:
Gulf War illness (GWI) affects up to 210,000 U.S. veterans who served in the Middle East during the Gulf War in 1990-1991. Symptoms include fatigue, muscle and joint pain, forgetfulness, headaches, rashes, and sleep disturbances. Routine exams cannot determine the cause of GWI. Researchers need more information to understand this disease.
Objective:
This natural history study will look for differences in Gulf War veterans who experienced GWI and those who did not.
Eligibility:
Gulf War veterans with GWI. Healthy Gulf War veterans who do not have GWI are also needed.
Design:
Participants will stay in the NIH Clinical Center as an inpatient for 2 weeks. They will undergo many tests.
Blood will be drawn many times throughout the study. Participants will also give urine, saliva, and stool samples.
Scans to measure the brain, leg muscles, bone density and body mass will be done.
They will have an exercise stress test and muscle strength tests.
They will have a sleep study. They will have tests to look at how well the brain, heart and lungs are working.
Participants will sleep in a specialized room that measures the amount of oxygen they use and the carbon dioxide they produce on four consecutive nights.
A sample of fluid will be collected from inside the spine.
Participants will take many surveys. Some will ask about their activities. Some will be about emotional and mental health. Some will be about thinking, memory, and behavior.
Optional tests include other imaging scans and testing the autonomic nervous system. Samples of skin and muscle may be taken.
After discharge, participants will wear activity monitors for 14 days. They will keep a diary of their symptoms, including fatigue, pain, and sleep, while wearing the monitors.
Detailed description
Study Description:
This protocol is part of a joint collaboration with the Veterans' Administration (VA) known as (Project IN-DEPTH). The Veterans' Administration protocol will recruit and identify participants for the NIH study, and maintain a repository of data and samples through a VA protocol (VA IN-DEPTH). The NIH protocol (NIH IN-DEPTH) will conduct deep phenotyping evaluations on study participants.
Gulf War Illness (GWI) and Gulf War Chronic Multi-Symptom Illness are names that have been used to describe a disorder of fatigue, muscle and joint pain, loss of concentration, forgetfulness, headache, respiratory complaints, rashes, sleep disturbances, and/or gastrointestinal distress. The purpose of this study is to learn more about GWI from veterans deployed in Persian Gulf during the first Gulf War.
In this study, two groups of veterans who were deployed to the Persian Gulf war between August 1990 and June 1991 will be enrolled: those who are healthy veteran controls (HVC) and those with GWI. Participants will have an inpatient study visit typically lasting 14 days to explore clinical and biological phenotypes through evaluations via questionnaires, medical procedures such as exercise testing, history and physical examination, and laboratory evaluation of samples.
This protocol is a "sister study" to the NIH protocol 16-N-0058: Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome (ME/CFS) at NIH. The symptoms of GWI and ME/CFS are very similar and much may be learned about each disorder through comparison. For this reason, the two studies will use similar methods. Participants in 16-N-0058 had previously consented to sharing of data, therefore datasets from this NIH IN-DEPTH protocol and 16-N-0058 will be shared and combined to perform several of the planned exploratory analyses.
This study will take place at the National Institutes of Health (NIH) Clinical Center in Bethesda, Maryland.
Objectives: Primary Objective:
To explore and compare the clinical and biological phenotypes of veterans with GWI and healthy veteran controls (HVC) at baseline.
Exploratory Objectives:
To explore the pathophysiology of fatigue and GWI symptom flares. Fatigue will be explored using tasks designed to create muscular and cognitive fatigue. GWI symptom flares will be explored using an exercise stress test and measuring the symptomatic and biological changes.
To compare the clinical and biological phenotypes between GWI, HVC, ME/CFS, and healthy volunteers.
Endpoints: Outcome measures
The primary purpose of this protocol is to perform exploratory analysis of collected data and samples for the generation of new hypotheses regarding GWI. The types of analyses to be performed will be wide ranging. Planned areas of focus may include:
- Characterization of the immune system and inflammatory signaling.
- Characterization of the pattern of microbiome.
- Characterization of bioenergetics, autonomic, and metabolic function.
- Characterization of neurocognition.
Study design
- Observational model
- Other
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| GWI | – | –Gulf War Veterans |
| HVC | – | –Healthy Volunteer Controls |
Who may qualify
- Ages
- 48 to 70 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- A Target of 50 GWI participants and 25 Healthy volunteer controls will be selected.
Key inclusion criteria (8 listed)
- Ability to provide informed consent
- Stated willingness to comply with all study procedures and availability for the duration of the study
- Age 48-70 at time of enrollment into VA IN-DEPTH Study
- Veterans who were deployed to Gulf Region ODS/S between August 1990 - June 1991.
- Self-reported completion of at least the seventh grade of school.
Key exclusion criteria (27 listed)
- Current or past psychotic disorder including depression with psychosis, bipolar disorder with psychotic symptoms and schizophrenia
- Current DSM-5-defined major depression disorder, generalized anxiety disorder, posttraumatic stress disorder, panic disorder, or obsessive-compulsive disorder unless managed for more than six months with a stable treatment regimen
- Current or past substance use disorder within last five years as diagnosed on the Structured Clinical Interview for DSM-5 (SCID-5). Prior or prescription marijuana use within the past five years will not be an exclusion.
- Current suicidal ideation
- History of head injury leading to moderate or severe traumatic brain injury, as detailed by loss of consciousness for greater than 30 minutes, a Glasgow Coma Score of 12 or less at the time of injury, post-traumatic amnesia greater than one day, or brain-scan changes related to a head injury. Persons having a history of mild TBI (mTBI) will not be excluded.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
To explore and compare the clinical and biological phenotypes of veterans with GWI and healthy veteran controls (HVC) at baseline.
Time frame: one time visit
Evaluate a number of clinical and biological measures.
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 3 Nov 2026.
- NIH Clinical Center Detailed Web PageLink provided by the sponsor.
- Individual participant dataSharing planned: Undecided
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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.
Brian T Walitt, M.D. principal investigator
National Institute of Neurological Disorders and Stroke (NINDS)
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Gulf War Illness, run by National Institute of Neurological Disorders and Stroke (NINDS) 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 8 inclusion and 27 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: looking for participants now, as of the sponsor's last update on 3 Nov 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.
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?
Contact Cynthia L Vierria ((301) 594-6760, cynthia.vierria@nih.gov), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To explore and compare the clinical and biological phenotypes of veterans with GWI and healthy veteran controls (HVC) at baseline. (time frame: one time visit). 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 3 Nov 2026.