Recruiting

CBD vs. THC

Sponsor:

University of Minnesota

Code:

NCT06808048

Conditions

Chronic Pain Patients

Medical Cannabis Users

Eligibility Criteria

Sex: All

Age: 30 - 70+

Healthy Volunteers: Not accepted

Interventions

Cognitive testing

Task-based fMRI measure of face-name and verbal learning

Study Details

Brief summary:

This study will assess cognition, neural function, and drug exposure in chronic pain patients who have been prescribed medical cannabis and will differentiate outcomes based on use of specific CBD-dominant versus THC-dominant treatment products. This longitudinal study will recruit medical cannabis users from local dispensaries. Each participant will complete a baseline assessment prior to the start of medical cannabis use, monthly phone calls to assess treatment adherence, and a four-month follow- up assessment. The aims of this project are: Aim 1. To assess impacts of medical cannabis compounds on executive functions, learning and memory in adults to determine whether cognitive impairments are evident after the onset of cannabis use; Aim 2. To assess the impacts of medical cannabis compounds on white matter microstructure, functional brain activity and functional connectivity; Aim 3. To differentiate change over four months in these outcomes as a function of (a) age and (b) pre-to-post-treatment changes in blood levels of cannabinoid compounds.

Conditions

Chronic Pain Patients

Medical Cannabis Users

Study ID

NCT06808048

Start date

Jun 18, 2025

Status verified date

Jul, 2026

Completion date

Jul 31, 2029

Anticipated

Primary completion date

Jul 15, 2029

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 30 - 70+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Medical cannabis users (n=120) will be required to

1. Be ages 30-75;
2. Be qualified for a medical cannabis prescription based only on a diagnosis of chronic pain; note that individuals can, in theory, utilize medical cannabis for more than one qualifying condition. People with orthopedic pain will be prioritized.
3. Have normal or corrected-to-normal vision and hearing;
4. Be free of current and past DSM-V-defined substance use disorders; have < 5 lifetime recreational uses of illicit drugs.
5. Have limited daily exposure to nicotine (e.g., no daily smokers/vapers; use of nicotine products fewer than 5 occasions weekly);
6. Willing to abstain from alcohol, nicotine, and other (non-treatment) drugs for 24 hours prior to study. Abstinence will be verified by breathalyzer and urine drug screening; must not test positive on breathalyzer and urine drug screenings for any nonprescribed psychoactive substance or for cannabis (at baseline);
7. Must be right handed as assessed by the Edinburgh Handedness Inventory;
8. No history of daily cannabis use; limited cannabis product use (recreational or therapeutic) within the past three months;
9. Able to schedule and complete a multi-hour single session protocol;
10. Have sufficient manual mobility to be able to complete computerized neurocognitive assessments;
11. Able to communicate with the researchers by phone during the four month pre-post assessment interval

Pain patients who are not using medical cannabis (n=60) will be required to:

1. Be ages 30-75;
2. Suffer from a chronic pain condition that could qualify them for medical cannabis; People with orthopedic pain will be prioritized.
3. Have normal or corrected-to-normal vision and hearing;
4. Be free of current and past DSM-V-defined substance use disorders; have < 5 lifetime recreational uses of illicit drugs.
5. Have limited daily exposure to nicotine (e.g., no daily smokers/vapers; use of nicotine products fewer than 5 occasions weekly);
6. Willing to abstain from alcohol, nicotine, and other (non-treatment) drugs for 24 hours prior to study. Abstinence will be verified by breathalyzer and urine drug screening; must not test positive on breathalyzer and urine drug screenings for any non- prescribed psychoactive substance or for cannabis (at baseline);
7. Must be right handed as assessed by the Edinburgh Handedness Inventory;
8. No history of daily cannabis use; cannabis use within the past three months limited to a few times.
9. Able to schedule and complete a multi-hour single session protocol;
10. Have sufficient manual mobility to be able to complete computerized neurocognitive assessments;
11. Able to communicate with the researchers by phone during the four month pre-post assessment interval Within both groups, concomitant opioid use will be allowed as will other prescribed treatments. Controls will be matched to the cannabis group on age, sex, socioeconomic status (SES), type of pain condition (orthopedic pain will be targeted) and comorbid opioid use.

All potential participants must indicate at the baseline enrollment that they have no immediate plans to relocate from the Twin Cities metro area (e.g., must be willing and able to participate in longitudinal assessment for a four-month period).

Exclusion Criteria:

1. Cannot have a degenerative neurological condition or a neurological condition that impacts brain function (e.g., epilepsy);
2. No contraindications to MRI scanning;
3. No lifetime history of severe DSM-V psychopathology (psychotic disorders, bipolar disorder); if currently treated mood for anxiety disorders, must be stable;
4. No current pregnancy or pregnancy within the prior 3 months; cannot be lactating;

Study Design

Enrollment

180 participants

Anticipated

Intervention Model

Single group

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Experimental cognitive and fMRI-based tasks

One primary aim of this study is to examine cognitive functioning in individuals who use medical cannabis. All participants in the study will complete cognitive measures that include measures of attention, learning, memory and executive function. All participants will complete task fMRI-based measures of learning and memory. NIH considers the cognitive and fMRI tasks to be interventions. The fMRI learning and memory tasks measures face-name associative learning and verbal associative learning. Brain activations are measured in response to each task. Each participant will complete two cognitive testing sessions as well as two fMRI sessions during the course of the study.

Interventions

Cognitive testing

Participants will complete a cognitive testing battery that includes measures of attention, learning, memory, problem-solving and executive function.

Task-based fMRI measure of face-name and verbal learning

Cognitive testing Participants will complete a cognitive battery that includes measures of attention, learning, memory, and executive function. Behavioral: Task-based fMRI measure of face-name and verbal learning. These tasks will assess cannabis effects on explicit associative learning and memory mediated by frontohippocampal networks. Participants memorize face-name or word pairs (encoding), then recall the names and word pairs after a delay. The first encoding block begins with a "MEMORIZE" cue followed by 5 face-name or word pairs; participants press a button when each pair is encoded. A distractor block follows. Next, a retrieval block begins with a "RECALL" cue, followed by the same faces or words paired with a recall prompt, with a 4-second stimulus duration. On recall trials, participants indicate recall of the name for the displayed face or word stem and engage in silent uncued recall of learned pairs. After the scan, participants are tested for retrieval accuracy.

Primary outcome measure

  • Rey Auditory Verbal Learning Test [ Time Frame: Administered at baseline and after four months ]
  • Digit Span Task [ Time Frame: Administered at baseline and after four months ]
  • Verbal Fluency Task [ Time Frame: Administered at baseline and after four months ]
  • Spatial Span Task [ Time Frame: Administered at baseline and after four months ]
  • Grooved Pegboard Task [ Time Frame: Administered at baseline and after four months ]
  • CANTAB Spatial Paired Associates Learning Task [ Time Frame: Administered at baseline and after four months ]
  • CANTAB Stockings of Cambridge Task [ Time Frame: Administered at baseline and after four months ]
  • CANTAB Self-Ordered Search Task [ Time Frame: Assessed at baseline and after four months ]
  • Iowa Gambling Task (IGT) [ Time Frame: Assessed at baseline and after four months ]
  • Face-Name Learning Task. [ Time Frame: Administered at baseline and after four months ]
  • Verbal Paired Associates Learning Task. [ Time Frame: Administered at baseline and after four months ]
  • Intrinsic functional brain activity [ Time Frame: Administered at baseline and after four months ]
  • MRI measurement of cortical thickness and white matter volume [ Time Frame: Administered at baseline and after four months ]
  • Frontostriatal structural and functional neural connectivity [ Time Frame: Assessed at baseline and after four months ]
  • Frontohippocampal structural and functional connectivity [ Time Frame: Assessed at baseline and after four months ]
  • Cannabis Use Disorder Identification Test (CUDIT) [ Time Frame: Baseline and monthly for four months thereafter ]
  • Blood levels of cannabinoid compounds [ Time Frame: Collected at baseline and after four months ]
  • Structured Clinical Interview for DSM-V Substance Use Module [ Time Frame: Assessed at baseline and after four months ]
  • Daily Medication Diary [ Time Frame: Daily for the four month duration of the study ]

Central Contacts and Locations

Central contacts

Monica Luciana, Ph.D.

612-626-0757lucia003@umn.edu

Angela Birnbaum, Ph.D., MLS(ASCP), FAES

birnb002@umn.edu

Locations

University of Minnesota

Recruiting

Minneapolis, Minnesota, United States, 55455

More Information

Sponsor

University of Minnesota

Last update posted

Jul 14, 2026

Last verified

Jul, 2026

Keywords

  • cannabis
  • medical cannabis
  • brain MRI
  • pharmacokinetics

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of Minnesota on 2026-07-14.