Cannabis UseeCBDNCT05170217
Reducing the Harmful Effects of Cannabis Use: Finding the Optimal CBD:THC Ratio
A study testing THC and Cannabidiol in people with Cannabis Use, run by King's College London at 1 site in United Kingdom.
Trial summary
This study will recruit healthy volunteers who use cannabis infrequently. Each participant will attend the laboratory on five occasions: an initial visit to check that they are safe to join the study and four days of testing. Read more about this study
- Who is it for?
- Ages 21 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Cannabis Use
- What is being tested?
- THC and Cannabidiol
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 46 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 8 Nov 2017to 9 Jun 2019
- 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 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Female and male volunteers aged 21-50
- Have used cannabis at least once
- Willing to provide written informed consent
- Willing to provide blood samples
- Fluent English speaker
Who cannot join
- Past or present major mental illness
- Past or present major physical illness
- Past or present substance use disorder
- Past or present use of anti-psychotic or anti-depressant medications
- First degree relative with psychotic disorder
- Currently taking psychotropic medication
Show all 16Show fewer
- Positive urine drug screen at screening or experimental visits
- Use of alcohol 24h prior to experimental visit or tobacco on the day of experiment
- Pregnancy (current or planned) or lactation in women
- Significant abnormality detected during physical examination at screening visit
- Cannabis use (defined as days in which cannabis is used recreationally) more than once per week on average over the last 12 months
- Any past use of synthetic cannabinoids
- Score of 5 and above on the Fagerstrom Nicotine dependence questionnaire
- BMI classified as obese or underweight
- Taken part in any drug study within the last 30 days or taking part in another study over the course of the trial
- Known drug sensitivity/allergy towards cannabis or Lorazepam
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
Institute of Psychiatry, Psychology and Neuroscience, King's College London
London, SE5 8AF
About this study
This study will recruit healthy volunteers who use cannabis infrequently. Each participant will attend the laboratory on five occasions: an initial visit to check that they are safe to join the study and four days of testing.
Participants will be administered, in a randomized order, vaporized cannabis containing one of four different ratios of CBD:THC (0:1, 1:1, 2:1, 3:1). The cannabis administration will follow a standardised inhalation procedure using a medical-grade vaporizer device.
Read more
Participants will complete a series of tasks measuring cognition, psychosis, anxiety and other subjective experiences.
The study will be carried out at the NIHR-Wellcome Trust Clinical Research Facility at King's College Hospital.
- Conditions
- Cannabis Use
- Being tested
- THC, Cannabidiol
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
THCDrug
Inhaled cannabis containing 10mg THC
CannabidiolDrug
Inhaled cannabis containing 10mg CBD
CannabidiolDrug
Inhaled cannabis containing 20mg CBD
CannabidiolDrug
Inhaled cannabis containing 30mg CBD
| Study group | Role | What they receive |
|---|---|---|
| CBD:THC 0:1 | Experimental | Inhalation of cannabis containing only THC Receives: Drug: THC |
| CBD:THC 1:1 | Experimental | Inhalation of cannabis containing THC and CBD Receives: Drug: THC; Drug: Cannabidiol |
| CBD:THC 2:1 | Experimental | Inhalation of cannabis containing THC and CBD Receives: Drug: THC; Drug: Cannabidiol |
| CBD:THC 3:1 | Experimental | Inhalation of cannabis containing THC and CBD Receives: Drug: THC; Drug: Cannabidiol |
What is being measured
The primary outcome is the main question the study is designed to answer.
Hopkins Verbal Learning Task
Delayed verbal recall
Measured: 40-45 minutes post cannabis inhalation
Secondary outcomes (14)
Hopkins Verbal Learning Task
Immediate verbal recall
Measured: 20-40 minutes post cannabis inhalation
Forward and Reverse Digit span
Working memory
Measured: 20-40 minutes post cannabis inhalation
Spatial N-back task
Spatial working memory
Measured: 20-40 minutes post cannabis inhalation
Positive and Negative Syndrome Scale
Positive subscale
Measured: Baseline; 3-4 hours post cannabis inhalation
State Social Paranoia Scale
Measured: 3-4 hours post cannabis inhalation
Community assessment of Psychic Experiences - state
Measured: 3-4 hours post cannabis inhalation
Psychotomimetic states inventory
Measured: 3-4 hours post cannabis inhalation
Visual analogue scales (0 to 100 millimetres)
- Feel drug effect
- Like drug effect
- Want more drug
- Mentally impaired
- Dry Mouth
- Enhanced colour perception
- Enhanced sound perception
- Want food
- Want alcohol
- Feel high
- Feel anxious
- Feel paranoid
- Feel tired
- Feel calm and relaxed
- Feel stoned
- The drug effects are pleasurable
Measured: Baseline; Pre-cannabis, 10 minutes post-cannabis, 50 minutes post-cannabis, 1 hour 10 minutes post-cannabis, discharge
Pleasurable responses - Visual analogue scale (-50 to 50 millimetres)
Increased or decreased pleasure from chocolate and music during intoxication
Measured: 1 hour post-cannabis
Plasma THC concentration
Measured: Pre-cannabis, 0 minutes post-cannabis, 5 minutes post-cannabis, 15 minutes post-cannabis, 90 minutes post-cannabis
Plasma CBD concentration
Measured: Pre-cannabis, 0 minutes post-cannabis, 5 minutes post-cannabis, 15 minutes post-cannabis, 90 minutes post-cannabis
Plasma 11-OH-THC concentration
Measured: Pre-cannabis, 0 minutes post-cannabis, 5 minutes post-cannabis, 15 minutes post-cannabis, 90 minutes post-cannabis
Plasma 11-COOH-THC concentration
Measured: Pre-cannabis, 0 minutes post-cannabis, 5 minutes post-cannabis, 15 minutes post-cannabis, 90 minutes post-cannabis
Plasma 7-OH-CBD concentration
Measured: Pre-cannabis, 0 minutes post-cannabis, 5 minutes post-cannabis, 15 minutes post-cannabis, 90 minutes post-cannabis
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Dec 2021
- Study start8 Nov 2017
- Primary completion9 Jun 2019
- Study completion9 Jun 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Cannabis UseStudies of the same condition, open and under way.
- More trials run by King's College LondonThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 46 participants (actual)
Sponsor and investigators
- Lead sponsor
- King's College London
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05170217
- Sponsor's protocol ID
- HR-16/17-4163
- Acronym
- eCBD
- Status last verified
- Nov 2021
- First submitted
- 17 Nov 2021
- Last updated
- 27 Dec 2021
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Oliver D, Englund A, Chesney E, Chester L, Wilson J, Sovi S, Wigroth S, Hodsoll J, Strang J, Murray RM, Freeman TP, Fusar-Poli P, McGuire P. Cannabidiol does not attenuate acute delta-9-tetrahydrocannabinol-induced attentional bias in healthy volunteers: A randomised, double-blind, cross-over study. Addiction. 2024 Feb;119(2):322-333. doi: 10.1111/add.16353. Epub 2023 Oct 11.
PubMed 37821096Chester LA, Englund A, Chesney E, Oliver D, Wilson J, Sovi S, Dickens AM, Oresic M, Linderman T, Hodsoll J, Minichino A, Strang J, Murray RM, Freeman TP, McGuire P. Effects of Cannabidiol and Delta-9-Tetrahydrocannabinol on Plasma Endocannabinoid Levels in Healthy Volunteers: A Randomized Double-Blind Four-Arm Crossover Study. Cannabis Cannabinoid Res. 2024 Feb;9(1):188-198. doi: 10.1089/can.2022.0174. Epub 2022 Dec 9.
PubMed 36493386
Study at a glance
From the registry record, last updated by the sponsor on 27 Dec 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Reducing the Harmful Effects of Cannabis Use: Finding the Optimal CBD:THC Ratio
- ClinicalTrials.gov ID
- NCT05170217
- Acronym / sponsor ID
- eCBD / HR-16/17-4163
- Conditions
- Cannabis Use
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 46 participants (actual)
- Lead sponsor
- King's College LondonUniversity, hospital or other
- Study start
- 8 Nov 2017 (actual)
- Primary completion
- 9 Jun 2019 (actual)
- Study completion
- 9 Jun 2019 (actual)
- First posted
- 27 Dec 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study will recruit healthy volunteers who use cannabis infrequently. Each participant will attend the laboratory on five occasions: an initial visit to check that they are safe to join the study and four days of testing.
Participants will be administered, in a randomized order, vaporized cannabis containing one of four different ratios of CBD:THC (0:1, 1:1, 2:1, 3:1). The cannabis administration will follow a standardised inhalation procedure using a medical-grade vaporizer device.
Participants will complete a series of tasks measuring cognition, psychosis, anxiety and other subjective experiences.
The study will be carried out at the NIHR-Wellcome Trust Clinical Research Facility at King's College Hospital.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| CBD:THC 0:1 | Experimental | Drug: THCInhalation of cannabis containing only THC |
| CBD:THC 1:1 | Experimental | Drug: THC, Drug: CannabidiolInhalation of cannabis containing THC and CBD |
| CBD:THC 2:1 | Experimental | Drug: THC, Drug: CannabidiolInhalation of cannabis containing THC and CBD |
| CBD:THC 3:1 | Experimental | Drug: THC, Drug: CannabidiolInhalation of cannabis containing THC and CBD |
Who may qualify
- Ages
- 21 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Female and male volunteers aged 21-50
- Have used cannabis at least once
- Willing to provide written informed consent
- Willing to provide blood samples
- Fluent English speaker
Key exclusion criteria (16 listed)
- Past or present major mental illness
- Past or present major physical illness
- Past or present substance use disorder
- Past or present use of anti-psychotic or anti-depressant medications
- First degree relative with psychotic disorder
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| THCInhaled cannabis containing 10mg THC | Drug | CBD:THC 0:1, CBD:THC 1:1, CBD:THC 2:1, CBD:THC 3:1 |
| CannabidiolInhaled cannabis containing 10mg CBD | Drug | CBD:THC 1:1 |
| CannabidiolInhaled cannabis containing 20mg CBD | Drug | CBD:THC 2:1 |
| CannabidiolInhaled cannabis containing 30mg CBD | Drug | CBD:THC 3:1 |
Primary outcome
Hopkins Verbal Learning Task
Time frame: 40-45 minutes post cannabis inhalation
Delayed verbal recall
14 secondary outcomes
Hopkins Verbal Learning Task
Time frame: 20-40 minutes post cannabis inhalation
Forward and Reverse Digit span
Time frame: 20-40 minutes post cannabis inhalation
Spatial N-back task
Time frame: 20-40 minutes post cannabis inhalation
Positive and Negative Syndrome Scale
Time frame: Baseline; 3-4 hours post cannabis inhalation
State Social Paranoia Scale
Time frame: 3-4 hours post cannabis inhalation
Community assessment of Psychic Experiences - state
Time frame: 3-4 hours post cannabis inhalation
Psychotomimetic states inventory
Time frame: 3-4 hours post cannabis inhalation
Visual analogue scales (0 to 100 millimetres)
Time frame: Baseline; Pre-cannabis, 10 minutes post-cannabis, 50 minutes post-cannabis, 1 hour 10 minutes post-cannabis, discharge
Pleasurable responses - Visual analogue scale (-50 to 50 millimetres)
Time frame: 1 hour post-cannabis
Plasma THC concentration
Time frame: Pre-cannabis, 0 minutes post-cannabis, 5 minutes post-cannabis, 15 minutes post-cannabis, 90 minutes post-cannabis
Plasma CBD concentration
Time frame: Pre-cannabis, 0 minutes post-cannabis, 5 minutes post-cannabis, 15 minutes post-cannabis, 90 minutes post-cannabis
Plasma 11-OH-THC concentration
Time frame: Pre-cannabis, 0 minutes post-cannabis, 5 minutes post-cannabis, 15 minutes post-cannabis, 90 minutes post-cannabis
Plasma 11-COOH-THC concentration
Time frame: Pre-cannabis, 0 minutes post-cannabis, 5 minutes post-cannabis, 15 minutes post-cannabis, 90 minutes post-cannabis
Plasma 7-OH-CBD concentration
Time frame: Pre-cannabis, 0 minutes post-cannabis, 5 minutes post-cannabis, 15 minutes post-cannabis, 90 minutes post-cannabis
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Dec 2021.
- Derived from this study: PubMed 37821096Oliver D, Englund A, Chesney E, Chester L, Wilson J, Sovi S, Wigroth S, Hodsoll J, Strang J, Murray RM, Freeman TP, Fusar-Poli P, McGuire P. Cannabidiol does not attenuate acute delta-9-tetrahydrocannabinol-induced attentional bias in healthy volunteers: A randomised, double-blind, cross-over study. Addiction. 2024 Feb;119(2):322-333. doi: 10.1111/add.16353. Epub 2023 Oct 11.
- Derived from this study: PubMed 36493386Chester LA, Englund A, Chesney E, Oliver D, Wilson J, Sovi S, Dickens AM, Oresic M, Linderman T, Hodsoll J, Minichino A, Strang J, Murray RM, Freeman TP, McGuire P. Effects of Cannabidiol and Delta-9-Tetrahydrocannabinol on Plasma Endocannabinoid Levels in Healthy Volunteers: A Randomized Double-Blind Four-Arm Crossover Study. Cannabis Cannabinoid Res. 2024 Feb;9(1):188-198. doi: 10.1089/can.2022.0174. Epub 2022 Dec 9.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing THC and Cannabidiol in people with Cannabis Use, run by King's College London at 1 site in United Kingdom.
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 16 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: finished, as of the sponsor's last update on 27 Dec 2021. 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 Kingdom. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Hopkins Verbal Learning Task (time frame: 40-45 minutes post cannabis inhalation). 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 NCT05170217, which also lists 2 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 27 Dec 2021.