Medical cannabis and the brain: new study tracks memory and thinking over four months
NCT ID NCT06808048
First seen Jul 14, 2026 · Last updated Jul 15, 2026 · Updated 1 time
Summary
This study follows 180 adults aged 30–75 with chronic pain who are prescribed medical cannabis. Researchers test memory, attention, and problem-solving skills, and use brain scans to see how cannabis compounds affect brain structure and activity. Participants are tracked for four months to compare the effects of CBD-dominant versus THC-dominant products.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- medical cannabis (CBD-dominant and THC-dominant products)
- What this could lead to
- If successful, this study could clarify how different cannabis compounds affect memory, attention, and brain health in people with chronic pain.
- What could go wrong
- This is an observational study, not a controlled trial, so it cannot prove cause and effect. Results may not apply to all cannabis users or pain conditions.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
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Not a phased trial
Phase numbers describe drug development. The registry uses this when they do not apply, as it does for trials of devices, procedures or behaviour changes, and for observational studies.
- Participants
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About 180 people
The number the study aims to enrol. It can still change while the study runs.
- Started
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Jun 2025
- Expected to finish
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Jul 2029
An estimate. End dates often move.
- Lead sponsor
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Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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30 to 75 years
- Sex
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Anyone
- Healthy volunteers
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Not accepted
This study is not open to healthy volunteers. The entry requirements below say who it is open to.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
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;
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
How to take part
Only the study team decides who joins. These are the ways to reach them.
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The places running it
1 site. The list below names each one and where it is.
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The official record
ClinicalTrials.gov lists the study team's own contact details, including names and phone numbers. We don't republish those.
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A doctor treating you
A doctor who knows your case can contact a study site on your behalf, and can tell you whether this study is worth pursuing at all.
Contacts and locations
Locations
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University of Minnesota
RECRUITINGMinneapolis, Minnesota, 55455, United States