Clinical trial NCT05170217: Reducing the Harmful Effects of Cannabis Use: Finding the Optimal CBD:THC Ratio
Official title: Reducing the Harmful Effects of Cannabis Use: Finding the Optimal CBD:THC Ratio
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Cannabis Use
Lead sponsor: King's College London
Sponsor class: OTHER
First posted: 2021-12-27
Enrollment: 46
Sex: ALL
Minimum age (years): 21
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

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.


Eligibility criteria: Inclusion Criteria:

* 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

Exclusion Criteria:

* 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
* Known drug sensitivity/allergy towards cannabis or Lorazepam

Primary outcomes:
measure: Hopkins Verbal Learning Task
timeFrame: 40-45 minutes post cannabis inhalation
Secondary outcomes:
measure: Hopkins Verbal Learning Task
timeFrame: 20-40 minutes post cannabis inhalation
measure: Forward and Reverse Digit span
timeFrame: 20-40 minutes post cannabis inhalation
measure: Spatial N-back task
timeFrame: 20-40 minutes post cannabis inhalation
measure: Positive and Negative Syndrome Scale
timeFrame: Baseline; 3-4 hours post cannabis inhalation
measure: State Social Paranoia Scale
timeFrame: 3-4 hours post cannabis inhalation
measure: Community assessment of Psychic Experiences - state
timeFrame: 3-4 hours post cannabis inhalation
measure: Psychotomimetic states inventory
timeFrame: 3-4 hours post cannabis inhalation
measure: Visual analogue scales (0 to 100 millimetres)
timeFrame: Baseline; Pre-cannabis, 10 minutes post-cannabis, 50 minutes post-cannabis, 1 hour 10 minutes post-cannabis, discharge
measure: Pleasurable responses - Visual analogue scale (-50 to 50 millimetres)
timeFrame: 1 hour post-cannabis
measure: Plasma THC concentration
timeFrame: Pre-cannabis, 0 minutes post-cannabis, 5 minutes post-cannabis, 15 minutes post-cannabis, 90 minutes post-cannabis
measure: Plasma CBD concentration
timeFrame: Pre-cannabis, 0 minutes post-cannabis, 5 minutes post-cannabis, 15 minutes post-cannabis, 90 minutes post-cannabis
measure: Plasma 11-OH-THC concentration
timeFrame: Pre-cannabis, 0 minutes post-cannabis, 5 minutes post-cannabis, 15 minutes post-cannabis, 90 minutes post-cannabis
measure: Plasma 11-COOH-THC concentration
timeFrame: Pre-cannabis, 0 minutes post-cannabis, 5 minutes post-cannabis, 15 minutes post-cannabis, 90 minutes post-cannabis
measure: Plasma 7-OH-CBD concentration
timeFrame: Pre-cannabis, 0 minutes post-cannabis, 5 minutes post-cannabis, 15 minutes post-cannabis, 90 minutes post-cannabis
Other outcomes:
Locations:
city: London
country: United Kingdom
facility: Institute of Psychiatry, Psychology and Neuroscience, King's College London
Study officials:
References: