HIVNCT07637669
Olfactory Function and Model-Based Behavior in People Living With HIV and SUD
An observational study of HIV and Substance Use Disorder, run by National Institute on Drug Abuse (NIDA) at 1 site in United States.
Trial summary
Background: Human immunodeficiency virus (HIV) infection can affect areas of the brain that control thinking ability. These same areas of the brain also control the sense of smell. HIV infection is common in people with substance use disorder (SUD). SUD also affects thinking ability. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- HIV, Substance Use Disorder
- How many people
- 120 participants
- Where
- 1 siteUnited States
- Study dates
- 29 Oct 2026to 27 Jun 2031
- 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 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: local community sample: metropolitan Baltimore area
Who may be able to join
- In order to be eligible to participate in this study, an individual must meet all of the following criteria:
- For all participants:
- Aged 18-65 years old. Justification: prevalence of olfactory impairments increases with age; after age 53, the prevalence is 24.5 percent, increasing to 62.5 percent in people ages 80-97.
- Ability of subject to understand and the willingness to sign a written informed consent document.
- For participants in the HIV+ and SUD+ and HIV+ and SUD- groups:
- 1. HIV positive.
- For participants in the HIV+ and SUD+ and HIV- \& SUD+ groups:
- 1. Current history (past 12 months) of Substance Use Disorder (SUD) or medical treatment for SUD, other than Alcohol Use Disorder (AUD) or Tobacco Use Disorder (TUD). Non-medical treatments for SUD will be evaluated on a case-by-case basis by the MAI.
Who cannot join
- An individual who meets any of the following criteria will be excluded from participation in this study:
- For all participants:
- History of neurological illnesses or neurosurgery including but not limited to cerebrovascular accident, Parkinson disease, Alzheimer disease, Huntington disease, central nervous system (CNS) tumor, significant head trauma with sequelae, multiple sclerosis or other demyelinating diseases, epilepsy, movement disorders. The MAI will also retain discretion to exclude based on a history of a neurological illness or trauma that may compromise data integrity.
- History of current (past 12 months) uncontrolled major DSM-5 psychiatric disorder including major affective disorder, obsessive-compulsive disorder, schizophrenia, or posttraumatic stress disorder, excluding SUD. This will be determined at the discretion of the MAI.
- Candidates who recently (12 hours prior to a study visit) used medications and/or substances that are psychoactive or otherwise affect alertness will have to pass a clinical assessment for intoxication on the day of the study visit. Based on participant preferences and MAI/PI judgment, participants who fail the clinical assessment for intoxication will either be withdrawn or rescheduled.
- History of clinically significant anaphylaxis, e.g., due to severe asthma or food and nonfood allergies (e.g., latex, detergents, soap, etc.). The MAI will retain discretion to exclude a participant based on this criterion.
Show all 18Show fewer
- Uncorrected impairments in visual acuity severe enough to affect task performance.
- Non-English speaking. Justification: The data integrity of some of the behavioral tasks used in this study would be compromised as they have only been validated in English.
- Pregnancy.
- Any other condition that in the judgment of the investigators is incompatible with participation.
- For participants in the HIV+ and SUD- and HIV- and SUD- groups:
- Lifetime history of SUD, excluding tobacco use disorder (TUD).
- Pattern of alcohol and drug use in the past 12 months that is indicative of harmful use, loss of control over use, or physical dependence.
- Daily alcohol or drug use (excluding caffeine and nicotine) for at least 4 continuous weeks in the past 12 months.
- For participants in the HIV- and SUD+ and HIV- and SUD- groups:
- 1. HIV positive.
- For the Optional MRI Segment:
- 1. Unable to undergo MRI scanning due to certain metallic or magnetic devices or implants in the body, or claustrophobia.
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 Institute on Drug Abuse
Baltimore, Maryland, 21224
Thorsten Kahnt, 667-312-5175, thorsten.kahnt@nih.gov
About this study
Official title: Olfactory Function and Model-based Behavior in People Living With HIV and SUD
Background:
Human immunodeficiency virus (HIV) infection can affect areas of the brain that control thinking ability. These same areas of the brain also control the sense of smell. HIV infection is common in people with substance use disorder (SUD). SUD also affects thinking ability. Researchers want to learn more about the connection between the sense of smell and decision-making ability in people with HIV, SUD, or both.
Read more
Objective:
To test the sense of smell in people with HIV and/or SUD and how they make choices based on odors.
Eligibility:
People aged 18 to 65 years with any of these: (1) HIV, (2) SUD, (3) both HIV and SUD, or (4) neither SUD nor HIV.
Design:
Participants will have 2 visits. Each visit will last 3 to 5 hours.
In visit 1, participants will have a blood draw and a saliva swab. They will answer questions about their health, sleep habits, food intake, and substance use. They will have smell tests:
They will smell scented sticks and answer questions about them. They will be blindfolded for some tests.
They will perform tasks on a computer. They will look at pictures and smell pleasant food odors, such as chocolate cake or pizza. Smells will be delivered using a nasal mask. Their sniffing and breathing will be measured. They may also be exposed to odor-free air. They will eat food that corresponds to one of the food odors they smelled.
In visit 2, participants will do a saliva swab and a different computer task that involves odors. They will also have tests of their attention and memory. Participants may opt to have an imaging scan of the brain.
Read the detailed description
Study Description:
Cognitive impairments persist in people living with Human Immunodeficiency Virus (HIV) despite anti-retroviral therapy (ART). However, these impairments remain under-characterized and it is not clear whether they include deficits in model-based control of behavior. HIV is common in people with substance use disorder (SUD) but the combined impact of HIV and SUD on cognition remains unclear. The olfactory system is uniquely vulnerable to neurodegeneration and overlaps with brain regions involved in decision making. This study will investigate olfactory function and model-based behavior in people living with HIV and SUD, and relate these measures to biomarkers of neurodegeneration.
Objectives:
The primary objective of this protocol is to compare olfactory function and performance on behavioral tasks assessing model-based behavior between people living with and without HIV, and between people with and without SUD.
Secondary objectives of this protocol are to compare blood-based and MRI-based biomarkers of neurodegeneration between people living with and without HIV, and between people with and without SUD.
Endpoints:
Primary:
- Olfactory function (Sniffin Sticks Threshold, Discrimination, and Identification tests)
- Behavior on tasks assessing model-based behavior (outcome devaluation and sensory preconditioning)
Secondary:
- Blood-based biomarker of neurodegeneration (Neurofilament Light Chain [NfL])
- MRI-based biomarker of neurodegeneration (Magnetic Resonance Imaging)
- Conditions
- HIV, Substance Use Disorder
- Keywords
- HIV, Substance Use Disorder, Olfaction, Decision Making
- Medical subject headings
- Substance-Related Disorders, Anosmia
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 |
|---|---|---|
| HIV- & SUD- | Individuals without HIV and without an SUD | |
| HIV- & SUD+ | Individuals without HIV and with an SUD | |
| HIV+ & SUD- | Individuals with HIV and without an SUD | |
| HIV+ & SUD+ | Individuals with HIV and with an SUD |
What is being measured
The primary outcome is the main question the study is designed to answer.
Olfactory function
Sniffin Sticks Threshold, Discrimination, and Identification tests
Measured: Visit 1
Model-based decision making
Model-based decision making as assessed in an outcome devaluation task (visit 1) and sensory preconditioning task (visit 2)
Measured: Visit 1 & 2
Secondary outcomes (2)
Neurofilament Light Chain
Plasma levels of neurofilament light chain [NfL]
Measured: Visit 1
MRI
MRI-based biomarkers of neurodegeneration
Measured: Visit 2 (optional)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Jun 2026
- Study start29 Oct 2026 (estimated)
- Primary completion27 Jun 2031 (estimated)
- Study completion27 Jun 2031 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HIVStudies of the same condition, open and under way.
- 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
- Case-control
- Time perspective
- Cross-sectional
- Enrolment
- 120 participants (estimated)
Sponsor and investigators
- Lead sponsor
- National Institute on Drug Abuse (NIDA)
- Sponsor type
- US National Institutes of Health
- Responsible party
- Sponsor
- Investigators
- Thorsten Kahnt, Ph.D., Principal investigator, National Institute on Drug Abuse (NIDA)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07637669
- Sponsor's protocol ID
- 10002591
- Other IDs
- 002591-DA
- Status last verified
- 6 Oct 2026
- First submitted
- 4 Jun 2026
- Last updated
- 26 Oct 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Individual participant data will be de-identified, which may be shared with (a) open data repositories and (b) with collaborators with whom proper data sharing agreements are in place, after consultation with and approval from the NIDA Technology Development Coordinator. The code to those data will not be shared. @@@@@@
Study at a glance
From the registry record, last updated by the sponsor on 26 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Olfactory Function and Model-based Behavior in People Living With HIV and SUD
- ClinicalTrials.gov ID
- NCT07637669
- Acronym / sponsor ID
- 10002591
- Conditions
- HIV, Substance Use Disorder
- Keywords
- HIV, Substance Use Disorder, Olfaction, Decision Making
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 120 participants (estimated)
- Lead sponsor
- National Institute on Drug Abuse (NIDA)US National Institutes of Health
- Study start
- 29 Oct 2026 (estimated)
- Primary completion
- 27 Jun 2031 (estimated)
- Study completion
- 27 Jun 2031 (estimated)
- First posted
- 10 Jun 2026 (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:
Human immunodeficiency virus (HIV) infection can affect areas of the brain that control thinking ability. These same areas of the brain also control the sense of smell. HIV infection is common in people with substance use disorder (SUD). SUD also affects thinking ability. Researchers want to learn more about the connection between the sense of smell and decision-making ability in people with HIV, SUD, or both.
Objective:
To test the sense of smell in people with HIV and/or SUD and how they make choices based on odors.
Eligibility:
People aged 18 to 65 years with any of these: (1) HIV, (2) SUD, (3) both HIV and SUD, or (4) neither SUD nor HIV.
Design:
Participants will have 2 visits. Each visit will last 3 to 5 hours.
In visit 1, participants will have a blood draw and a saliva swab. They will answer questions about their health, sleep habits, food intake, and substance use. They will have smell tests:
They will smell scented sticks and answer questions about them. They will be blindfolded for some tests.
They will perform tasks on a computer. They will look at pictures and smell pleasant food odors, such as chocolate cake or pizza. Smells will be delivered using a nasal mask. Their sniffing and breathing will be measured. They may also be exposed to odor-free air. They will eat food that corresponds to one of the food odors they smelled.
In visit 2, participants will do a saliva swab and a different computer task that involves odors. They will also have tests of their attention and memory. Participants may opt to have an imaging scan of the brain.
Detailed description
Study Description:
Cognitive impairments persist in people living with Human Immunodeficiency Virus (HIV) despite anti-retroviral therapy (ART). However, these impairments remain under-characterized and it is not clear whether they include deficits in model-based control of behavior. HIV is common in people with substance use disorder (SUD) but the combined impact of HIV and SUD on cognition remains unclear. The olfactory system is uniquely vulnerable to neurodegeneration and overlaps with brain regions involved in decision making. This study will investigate olfactory function and model-based behavior in people living with HIV and SUD, and relate these measures to biomarkers of neurodegeneration.
Objectives:
The primary objective of this protocol is to compare olfactory function and performance on behavioral tasks assessing model-based behavior between people living with and without HIV, and between people with and without SUD.
Secondary objectives of this protocol are to compare blood-based and MRI-based biomarkers of neurodegeneration between people living with and without HIV, and between people with and without SUD.
Endpoints:
Primary:
- Olfactory function (Sniffin Sticks Threshold, Discrimination, and Identification tests)
- Behavior on tasks assessing model-based behavior (outcome devaluation and sensory preconditioning)
Secondary:
- Blood-based biomarker of neurodegeneration (Neurofilament Light Chain [NfL])
- MRI-based biomarker of neurodegeneration (Magnetic Resonance Imaging)
Study design
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| HIV- & SUD- | – | –Individuals without HIV and without an SUD |
| HIV- & SUD+ | – | –Individuals without HIV and with an SUD |
| HIV+ & SUD- | – | –Individuals with HIV and without an SUD |
| HIV+ & SUD+ | – | –Individuals with HIV and with an SUD |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- local community sample: metropolitan Baltimore area
Key inclusion criteria (8 listed)
- In order to be eligible to participate in this study, an individual must meet all of the following criteria:
- Aged 18-65 years old. Justification: prevalence of olfactory impairments increases with age; after age 53, the prevalence is 24.5 percent, increasing to 62.5 percent in people ages 80-97.
- Ability of subject to understand and the willingness to sign a written informed consent document.
- 1. HIV positive.
- 1. Current history (past 12 months) of Substance Use Disorder (SUD) or medical treatment for SUD, other than Alcohol Use Disorder (AUD) or Tobacco Use Disorder (TUD). Non-medical treatments for SUD will be evaluated on a case-by-case basis by the MAI.
Key exclusion criteria (18 listed)
- An individual who meets any of the following criteria will be excluded from participation in this study:
- History of neurological illnesses or neurosurgery including but not limited to cerebrovascular accident, Parkinson disease, Alzheimer disease, Huntington disease, central nervous system (CNS) tumor, significant head trauma with sequelae, multiple sclerosis or other demyelinating diseases, epilepsy, movement disorders. The MAI will also retain discretion to exclude based on a history of a neurological illness or trauma that may compromise data integrity.
- History of current (past 12 months) uncontrolled major DSM-5 psychiatric disorder including major affective disorder, obsessive-compulsive disorder, schizophrenia, or posttraumatic stress disorder, excluding SUD. This will be determined at the discretion of the MAI.
- Candidates who recently (12 hours prior to a study visit) used medications and/or substances that are psychoactive or otherwise affect alertness will have to pass a clinical assessment for intoxication on the day of the study visit. Based on participant preferences and MAI/PI judgment, participants who fail the clinical assessment for intoxication will either be withdrawn or rescheduled.
- History of clinically significant anaphylaxis, e.g., due to severe asthma or food and nonfood allergies (e.g., latex, detergents, soap, etc.). The MAI will retain discretion to exclude a participant based on this criterion.
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
Olfactory function
Time frame: Visit 1
Sniffin Sticks Threshold, Discrimination, and Identification tests
Model-based decision making
Time frame: Visit 1 & 2
Model-based decision making as assessed in an outcome devaluation task (visit 1) and sensory preconditioning task (visit 2)
2 secondary outcomes
Neurofilament Light Chain
Time frame: Visit 1
MRI
Time frame: Visit 2 (optional)
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 26 Oct 2026.
- Individual participant dataSharing planned: Yes. Individual participant data will be de-identified, which may be shared with (a) open data repositories and (b) with collaborators with whom proper data sharing agreements are in place, after consultation with and approval from the NIDA Technology Development Coordinator. The code to those data will not be shared. @@@@@@
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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.
Thorsten Kahnt, Ph.D. principal investigator
National Institute on Drug Abuse (NIDA)
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 HIV and Substance Use Disorder, run by National Institute on Drug Abuse (NIDA) 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 18 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 26 Oct 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 NIDA IRP Screening Team ((800) 535-8254, researchstudies@nida.nih.gov), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Olfactory function (time frame: Visit 1). The study lists 2 primary outcomes in all. 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 26 Oct 2026.