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Cannabis UseTHC-YANCT06077292

Cannabis THC Potency, Metabolism, and Cognitive Impairment in Young Adults

A study testing 15% THC Potency Reduction and 35% THC Potency Reduction in people with Cannabis Use and THC, run by University of California, San Francisco at 1 site in United States.

Suspended

Paused. Enrolment is on hold for now and may resume.

Official record
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Trial summary

The goal of this interventional study is to determine the impact of high potency THC product use on cognitive function of young adults aged 21-25. The main question it aims to answer is: will cannabis users who switch to less potent THC products demonstrate improved cognitive function compared to baseline? Other… Read more about this study

Who is it for?
Ages 21 to 25 yearsHealthy volunteers can take part
Conditions the study is for
Cannabis Use, THC, Marijuana Use
What is being tested?
15% THC Potency Reduction and 35% THC Potency Reduction
Could I receive a placebo?
No, everyone receives an active treatment
How many people
110 participants
Where
1 siteUnited States
Study dates
17 Mar 2025to 14 Dec 2026
Phase
Interventional
Are there results?
None posted in the registry

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 21 to 25 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Between the ages of 21-25
  • Resides in San Francisco
  • Self-report cannabis concentrate use as their primary method of cannabis use
  • Self-report using cannabis daily or almost daily (i.e., at least 6 out of 7 days during each of the last 4 weeks)
  • Self-report only purchasing cannabis from regulated retail stores in California.

Who cannot join

  • Pregnant
  • Regularly uses other drugs (other than nicotine)

Trial locations and contacts

1 site in 1 country.

United States1 site
  • University of California San Francisco

    San Francisco, California, 94143

Other trials in United States

About this study

Official title: Impacts of THC Potency of Cannabis Concentrates and THC Metabolism on Cognitive Impairment in Young Adults

The goal of this interventional study is to determine the impact of high potency THC product use on cognitive function of young adults aged 21-25.

The main question it aims to answer is: will cannabis users who switch to less potent THC products demonstrate improved cognitive function compared to baseline?

Read more

Other questions this study aims to answer include:

  • Can researchers accurately assess THC consumption among frequent cannabis users?
  • Can researchers effectively incentivize cannabis users to use less potent THC products?
  • Do genetic variations in THC metabolism impact urinary THC excretion?
  • Do genetic variations in THC metabolism impact cognitive performance in cannabis users?
  • Are quantitative urinary THC values predictive of cognitive impairment?
  • How can researchers use research findings to inform harm reduction practices for people who use cannabis?

Participants will submit blood and urine samples and be incentivized to use less potent THC products.

Read the detailed description

The goal of this interventional study is to determine the impact of high potency THC product use on cognitive function of young adults aged 21-25.

The aims aims of this study are:

  1. Evaluate feasibility of assessing THC consumption, genetic variation in THC metabolism, urinary THC excretion, and cognitive performance in users of high potency cannabis products.
  2. Test the effectiveness of an incentivization protocol aimed at encouraging cannabis users to use less potent THC products as a means of harm reduction.
  3. Compare group differences between the high and low THC-reduction groups on THC metabolism (urine) and cognitive performance while controlling for any changes in frequency and amount of cannabis used.
  4. Identify whether participant predisposition to poorly metabolize THC (i.e., CYP2C9*3 carriers vs. others) impacts urinary THC excretion in the experimental condition relative to baseline in both groups.
  5. Identify whether participant predisposition to poorly metabolize THC (i.e., CYP2C9*3 carriers vs. others) impacts cognitive performance in the experimental condition relative to baseline in both groups.
  6. Determine whether quantitative urinary THC values correlate with measures of cognitive performance.
  7. Communicate basic findings regarding relationships between variables and outcomes in the form of a scorecard to help provide harm reduction strategies for youth who use cannabis.

Participants will:

  • Undergo a baseline assessment of cognitive performance and will submit blood and urine samples to assess genetic variation in THC metabolism, and baseline urinary THC excretion.
  • Be randomized to two groups: 1) lower THC reduction group (incentivized to use THC products that are at least 15% less potent than baseline) and 2) higher THC reduction group (incentivized to use THC products that are at least 35% less potent than baseline) .
  • Submit urine samples at baseline and weekly for 5 weeks to measure urinary THC excretion.
  • Complete weekly follow up surveys assessing cannabis use patterns, reinforcing value of the cannabis product(s) used, symptoms of cannabis withdrawal, and presence of positive and negative emotions.
  • Undergo re-assessment of cognitive performance after 5 weeks of intervention.

Researchers will compare if participants in each group are able to use less potent THC products and whether the use of less potent THC products results in improved cognitive function.

Being tested
15% THC Potency Reduction, 35% THC Potency Reduction
Keywords
Cannabis, Marijuana, High Potency THC, Dabs, Wax, Young Adult, Youth
Medical subject headings
Marijuana Use, Cognitive Dysfunction, Vaping, Marijuana Abuse

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • 15% THC Potency ReductionBehavioural

    Participants will be incentivized to use THC products that are at least 15% less potent than baseline

  • 35% THC Potency ReductionBehavioural

    Participants will be incentivized to use THC products that are at least 35% less potent than baseline

Study groups in NCT06077292
Study groupRoleWhat they receive
15% THC Potency Reduction GroupExperimentalParticipants will be incentivized to use THC products that are at least 15% less potent than baseline
Receives: Behavioral: 15% THC Potency Reduction
35% THC Potency Reduction GroupExperimentalParticipants will be incentivized to use THC products that are at least 35% less potent than baseline
Receives: Behavioral: 35% THC Potency Reduction

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in Rapid Visual Information Processing Score

    Cognitive performance will be assessed using the CANTAB, a computer-based cognitive assessment system. Participants in this study will complete a battery of seven neuropsychological tests. CANTAB is administered to subjects using a touch screen computer and is language- and culture- independent. Participants scores at 5 weeks will be compared to their baseline scores.

    The Rapid Visual Information Processing test takes 9 minutes to complete and is scored on a scale of 0-54, with a higher score indicative of better cognitive performance.

    Measured: Baseline and 5 weeks

  2. Change in Paired Associates Learning score

    Cognitive performance will be assessed using the CANTAB, a computer-based cognitive assessment system. Participants in this study will complete a battery of seven neuropsychological tests. CANTAB is administered to subjects using a touch screen computer and is language- and culture- independent. Participants scores at 5 weeks will be compared to their baseline scores.

    The Paired Associates Learning test takes 8 minutes to complete and is scored on a scale of 0-100%, with a higher percentage indicative of better cognitive performance.

    Measured: Baseline and 5 weeks

  3. Change in Delayed Matching-to-Sample Score

    Cognitive performance will be assessed using the CANTAB, a computer-based cognitive assessment system. Participants in this study will complete a battery of seven neuropsychological tests. CANTAB is administered to subjects using a touch screen computer and is language- and culture- independent. Participants scores at 5 weeks will be compared to their baseline scores.

    The Delayed Matching-to-Sample test takes 7 minutes to complete and is scored on a scale of 0-100%, with a higher percentage indicative of better cognitive performance.

    Measured: Baseline and 5 weeks

  4. Change in Verbal Recognition Memory score

    Cognitive performance will be assessed using the CANTAB, a computer-based cognitive assessment system. Participants in this study will complete a battery of seven neuropsychological tests. CANTAB is administered to subjects using a touch screen computer and is language- and culture- independent. Participants scores at 5 weeks will be compared to their baseline scores.

    The Verbal Recognition Memory test takes 6 minutes to complete and is scored on a scale of 0-36, with a higher score indicative of better cognitive performance

    Measured: Baseline and 5 weeks

  5. Change in Spatial Working Memory score

    Cognitive performance will be assessed using the CANTAB, a computer-based cognitive assessment system. Participants in this study will complete a battery of seven neuropsychological tests. CANTAB is administered to subjects using a touch screen computer and is language- and culture- independent. Participants scores at 5 weeks will be compared to their baseline scores.

    The Spatial Working Memory test takes 4 minutes to complete and is scored on a scale of 0-306, with a lower score indicative of fewer errors and better cognitive performance.

    Measured: Baseline and 5 weeks

  6. Change in One-Touch Stockings of Cambridge score

    Cognitive performance will be assessed using the CANTAB, a computer-based cognitive assessment system. Participants in this study will complete a battery of seven neuropsychological tests. CANTAB is administered to subjects using a touch screen computer and is language- and culture- independent. Participants scores at 5 weeks will be compared to their baseline scores.

    The One-Touch Stockings of Cambridge test takes 10 minutes to complete and scores are based on the time it takes for a participant to solve 20 problems. Shorter time to solve a problem is indicative of better cognitive performance.

    Measured: Baseline and 5 weeks

  7. Change in Stop Signal Task score

    Cognitive performance will be assessed using the CANTAB, a computer-based cognitive assessment system. Participants in this study will complete a battery of seven neuropsychological tests. CANTAB is administered to subjects using a touch screen computer and is language- and culture- independent. Participants scores at 5 weeks will be compared to their baseline scores.

    The Stop Signal Task test takes 14 minutes to complete and is scored on a scale of 1-1000 milliseconds, with a shorter time indicative of better cognitive performance.

    Measured: Baseline and 5 weeks

Secondary outcomes (6)
  1. Baseline Urinary THC Excretion

    Urinary THC excretion will be measured using liquid chromatography mass spectroscopy (LC/MS/MS). THC levels will be corrected/standardized for level of hydration by dividing total THC by total urine creatinine. Results range from <5 ng/mL to 5,000 ng/mL, with higher values indicative of more THC in the urine.

    Measured: Baseline

  2. Week 1 Urinary THC Excretion

    Urinary THC excretion will be measured using liquid chromatography mass spectroscopy (LC/MS/MS). THC levels will be corrected/standardized for level of hydration by dividing total THC by total urine creatinine. Results range from <5 ng/mL to 5,000 ng/mL, with higher values indicative of more THC in the urine. Week 1 THC levels will be compared to baseline urine THC levels.

    Measured: 7-10 days after study enrollment.

  3. Week 2 Urinary THC Excretion

    Urinary THC excretion will be measured using liquid chromatography mass spectroscopy (LC/MS/MS). THC levels will be corrected/standardized for level of hydration by dividing total THC by total urine creatinine. Results range from <5 ng/mL to 5,000 ng/mL, with higher values indicative of more THC in the urine. Week 2 THC levels will be compared to baseline THC levels.

    Measured: 14-17 days after study enrollment.

  4. Week 3 Urinary THC Excretion

    Urinary THC excretion will be measured using liquid chromatography mass spectroscopy (LC/MS/MS). THC levels will be corrected/standardized for level of hydration by dividing total THC by total urine creatinine. Results range from <5 ng/mL to 5,000 ng/mL, with higher values indicative of more THC in the urine. Week 3 THC levels will be compared to baseline THC levels.

    Measured: 21-24 days after study enrollment.

  5. Week 4 Urinary THC Excretion

    Urinary THC excretion will be measured using liquid chromatography mass spectroscopy (LC/MS/MS). THC levels will be corrected/standardized for level of hydration by dividing total THC by total urine creatinine. Results range from <5 ng/mL to 5,000 ng/mL, with higher values indicative of more THC in the urine. Week 4 THC levels will be compared to baseline THC levels.

    Measured: 28-30 days after study enrollment.

  6. Week 5 Urinary THC Excretion

    Urinary THC excretion will be measured using liquid chromatography mass spectroscopy (LC/MS/MS). THC levels will be corrected/standardized for level of hydration by dividing total THC by total urine creatinine. Results range from <5 ng/mL to 5,000 ng/mL, with higher values indicative of more THC in the urine. Week 5 THC levels will be compared to baseline THC levels.

    Measured: 35-38 days after study enrollment.

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted11 Oct 2023
  2. Study start17 Mar 2025
  3. Primary completion14 Mar 2026
  4. Study completion14 Dec 2026 (estimated)

Why it stopped: Funding has ended; seeking additional funding to continue

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Other
Allocation
Randomised
Intervention model
Parallel groups
Masking
Single blind
Who is masked
Investigator
Enrolment
110 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06077292
Sponsor's protocol ID
23-39581
Acronym
THC-YA
Status last verified
Apr 2026
First submitted
4 Oct 2023
Last updated
13 Apr 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Sachse-Seeboth C, Pfeil J, Sehrt D, Meineke I, Tzvetkov M, Bruns E, Poser W, Vormfelde SV, Brockmoller J. Interindividual variation in the pharmacokinetics of Delta9-tetrahydrocannabinol as related to genetic polymorphisms in CYP2C9. Clin Pharmacol Ther. 2009 Mar;85(3):273-6. doi: 10.1038/clpt.2008.213. Epub 2008 Nov 12.

    PubMed 19005461
  • Murray RM, Quigley H, Quattrone D, Englund A, Di Forti M. Traditional marijuana, high-potency cannabis and synthetic cannabinoids: increasing risk for psychosis. World Psychiatry. 2016 Oct;15(3):195-204. doi: 10.1002/wps.20341.

    PubMed 27717258
  • Ramaekers JG, Kauert G, van Ruitenbeek P, Theunissen EL, Schneider E, Moeller MR. High-potency marijuana impairs executive function and inhibitory motor control. Neuropsychopharmacology. 2006 Oct;31(10):2296-303. doi: 10.1038/sj.npp.1301068. Epub 2006 Mar 29.

    PubMed 16572123
  • D'Souza DC, Ganesh S, Cortes-Briones J, Campbell MH, Emmanuel MK. Characterizing psychosis-relevant phenomena and cognitive function in a unique population with isolated, chronic and very heavy cannabis exposure. Psychol Med. 2020 Oct;50(14):2452-2459. doi: 10.1017/S0033291719002721. Epub 2019 Oct 16.

    PubMed 31615592
  • Bidwell LC, Martin-Willett R, Karoly HC. Advancing the science on cannabis concentrates and behavioural health. Drug Alcohol Rev. 2021 Sep;40(6):900-913. doi: 10.1111/dar.13281. Epub 2021 Mar 30.

    PubMed 33783029
  • Bourque J, Potvin S. Cannabis and Cognitive Functioning: From Acute to Residual Effects, From Randomized Controlled Trials to Prospective Designs. Front Psychiatry. 2021 Jun 10;12:596601. doi: 10.3389/fpsyt.2021.596601. eCollection 2021.

    PubMed 34177633

Questions about this trial

What is this clinical trial studying?

A study testing 15% THC Potency Reduction and 35% THC Potency Reduction in people with Cannabis Use and THC, run by University of California, San Francisco 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 5 inclusion and 2 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: paused, as of the sponsor's last update on 13 Apr 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?

Results are not available in the source record.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in Rapid Visual Information Processing Score (time frame: Baseline and 5 weeks). The study lists 7 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT06077292, which also lists 6 linked publications.

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 13 Apr 2026.

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