Olfactory Function and Model-Based Behavior in People Living With HIV and SUD

What this study involves

The registry says this study is recruiting. Individual locations may have different availability.

Study type

Observational

Phase

Not applicable / not listed

Age range

18 years - 65 years

Sex eligible

All sexes

Healthy volunteers

Accepted

Participants

120 Estimated

These are starting points, not an eligibility decision. The research team must review the full requirements.

About the research

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.

Who may be able to participate?

The list below is the sponsor’s full registry wording. It can include conditions, prior treatment, test results and other requirements. A match in search does not mean you qualify.

• INCLUSION CRITERIA:

In order to be eligible to participate in this study, an individual must meet all of the following criteria:

For all participants:

1. 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.
2. 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), mild Cannabis Use Disorder (CUD), or Tobacco Use Disorder (TUD). Non-medical treatments for SUD will be evaluated on a case-by-case-basis by the MAI.

EXCLUSION CRITERIA:

An individual who meets any of the following criteria will be excluded from participation in this study:

For all participants:

1. 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.
2. History of current (past 3 months) symptomatic, more than mild 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.
3. 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.
4. 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.
5. Uncorrected impairments in visual acuity severe enough to affect task performance.
6. 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.
7. Pregnancy.
8. 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:

1. History (past 5 years) of SUD, excluding tobacco use disorder (TUD).
2. 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.
3. 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 participants in the HIV- \& SUD- group:

1\. Unable to undergo MRI scanning due to certain metallic or magnetic devices or implants in the body, or claustrophobia.

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.

Study population

local community sample: metropolitan Baltimore area

Treatment, groups and participation

The registry may describe treatments and study duration without a complete visit calendar. Ask the study team for the exact schedule, procedures, risks, costs and alternatives. Keep your usual care plan unless your treating clinician tells you otherwise.

Assignment

Not reported

Masking

Not reported

What researchers are measuring

Outcome measures describe what is being studied. They are not proof that a treatment works.

Primary measures

Secondary measures

Research locations (1)

The overall study status and a local site’s status can differ. Confirm that location’s availability before traveling.

1 locations

Study team and timeline

Lead sponsor

National Institute on Drug Abuse (NIDA)

Study start

Nov 15, 2026 Estimated

Primary completion

Jun 27, 2031 Estimated

Study completion

Jun 27, 2031 Estimated

First posted

Jun 10, 2026 Actual

Last updated

Nov 10, 2026 Actual

Official study contacts