Reducing the Harmful Effects of Cannabis Use: Finding the Optimal CBD:THC Ratio
eCBD
1 other identifier
interventional
46
1 country
1
Brief 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. 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.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P25-P50 for not_applicable
Started Nov 2017
1 active site
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
Study Start
First participant enrolled
November 8, 2017
CompletedPrimary Completion
Last participant's last visit for primary outcome
June 9, 2019
CompletedStudy Completion
Last participant's last visit for all outcomes
June 9, 2019
CompletedFirst Submitted
Initial submission to the registry
November 17, 2021
CompletedFirst Posted
Study publicly available on registry
December 27, 2021
CompletedDecember 27, 2021
November 1, 2021
1.6 years
November 17, 2021
December 9, 2021
Conditions
Outcome Measures
Primary Outcomes (1)
Hopkins Verbal Learning Task
Delayed verbal recall
40-45 minutes post cannabis inhalation
Secondary Outcomes (14)
Hopkins Verbal Learning Task
20-40 minutes post cannabis inhalation
Forward and Reverse Digit span
20-40 minutes post cannabis inhalation
Spatial N-back task
20-40 minutes post cannabis inhalation
Positive and Negative Syndrome Scale
Baseline; 3-4 hours post cannabis inhalation
State Social Paranoia Scale
3-4 hours post cannabis inhalation
- +9 more secondary outcomes
Study Arms (4)
CBD:THC 0:1
EXPERIMENTALInhalation of cannabis containing only THC
CBD:THC 1:1
EXPERIMENTALInhalation of cannabis containing THC and CBD
CBD:THC 2:1
EXPERIMENTALInhalation of cannabis containing THC and CBD
CBD:THC 3:1
EXPERIMENTALInhalation of cannabis containing THC and CBD
Interventions
Eligibility Criteria
You may qualify if:
- 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
You may not qualify if:
- 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
- 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
- +1 more criteria
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (1)
Institute of Psychiatry, Psychology and Neuroscience, King's College London
London, SE5 8AF, United Kingdom
Related Publications (2)
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.
PMID: 37821096DERIVEDChester 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.
PMID: 36493386DERIVED
MeSH Terms
Interventions
Intervention Hierarchy (Ancestors)
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- RANDOMIZED
- Masking
- DOUBLE
- Who Masked
- PARTICIPANT, INVESTIGATOR
- Purpose
- BASIC SCIENCE
- Intervention Model
- CROSSOVER
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
November 17, 2021
First Posted
December 27, 2021
Study Start
November 8, 2017
Primary Completion
June 9, 2019
Study Completion
June 9, 2019
Last Updated
December 27, 2021
Record last verified: 2021-11
Data Sharing
- IPD Sharing
- Will not share