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Smell sense and decision-making in people with HIV or substance use disorder

Tests smell and odor-based choices in people with HIV or substance use disorder.

Key facts

Who runs it
National Institute on Drug Abuse (NIDA)
Where
Baltimore, United StatesSee the site
Trial code
Registry title
Olfactory Function and Model-Based Behavior in People Living With HIV and SUD
Status
Recruiting
People taking part
120 people, planned
Starts
18 Nov 2026
Expected to end
27 Jun 2031
Type of study
Observational, 4 groups
Record updated
13 November 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for adults aged 18 to 65 with HIV, with substance use disorder, with both, or with neither. It studies the sense of smell and choices based on odors.

Age
18 to 65 years
Sex
All sexes can join.
Disease stage
Four groups: HIV-positive, substance use disorder (SUD), both HIV and SUD, or neither. SUD means use in the past 12 months or treatment for SUD. Alcohol, mild cannabis and tobacco use disorders do not count.
Biomarker or test result
HIV-positive for the HIV groups.

Main reasons for not taking part

  • History of brain or nerve illness or brain surgery, such as stroke, Parkinson disease, epilepsy
  • Current more than mild psychiatric disorder in the past 3 months, such as schizophrenia or PTSD
  • Recent use of substances that affect alertness, if they fail the check on the visit day
  • Serious anaphylaxis or severe allergies
  • Pregnancy

The registry criteria, word for word

Show all 21 criteriaShow less

Who cannot take part

  • 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preferences and MAI/PI judgment, participants who fail the clinical assessment for intoxication will either be withdrawn or rescheduled
  • 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
  • Unable to undergo MRI scanning due to certain metallic or magnetic devices or implants in the body, or claustrophobia; For the Optional MRI Segment:
  • Unable to undergo MRI scanning due to certain metallic or magnetic devices or implants in the body, or claustrophobia
  • 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 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
  • 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
  • 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:
  • History (past 5 years) of SUD, excluding tobacco use disorder (TUD)
  • 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:
  • HIV positive; For participants in the HIV- \& SUD- group:
  • An individual who meets any of the following criteria will be excluded from participation in this study:
  • For all participants:
  • 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

Other criteria

  • INCLUSION CRITERIA:; 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:
  • HIV positive; For participants in the HIV+ and SUD+ and HIV- \& SUD+ groups:
  • 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

Check if you might fit

Answer for yourself. This is not a decision: only the study team can say whether you can take part.

  • Are you between 18 and 65 years old?

Where in United States

  • National Institute on Drug AbuseBaltimore, United StatesContact: Thorsten KahntTaking people

About the trial

What the trial wants to find out

Background:

Read full original descriptionShow less

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.

The 4 groups in the trial

  • 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

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov.
Official title
Olfactory Function and Model-based Behavior in People Living With HIV and SUD
Plain-language title
Smell sense and decision-making in people with HIV or substance use disorderGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 14 November 2026.
Fit questions
Built from NCT07637669, who can take part
Record updated
13 November 2026