Does Cannabidiol Attenuate the Acute Effects of ∆9-tetrahydrocannabinol Intoxication in Individuals Diagnosed With Schizophrenia? A Double-blind, Randomised, Placebo-controlled Experimental Study

Not Applicable

Completed

• Conditions: Schizophrenia; Cannabis Use
• Interventions: Drug: Placebo; Drug: Cannabidiol; Drug: Delta-9-THC

• Registration Number: NCT04605393
• Lead Sponsor: King's College London

Brief Summary

This study will recruit schizophrenia patients who use cannabis recreationally. Each participant will attend the laboratory on three occasions: an initial visit to check that they are safe to join the study and two days of testing.

Participants will be administered, in a randomized order, a pre-treatment with either CBD (1000mg) orally or a matching placebo. On both experiments, participants will then inhale cannabis containing THC. The THC 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.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2020-10-05
• Study First Submitted QC: 2020-10-21
• Study First Posted: 2020-10-28
• Study Start: 2021-01-01
• Primary Completion: 2023-07-07
• Study Completion: 2023-07-07
• Status Verified: 2023-08
• Last Update Submitted: 2023-08-15
• Last Update Posted: 2023-08-18

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 36

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Placebo/THC	Placebo	Oral placebo followed by inhalation of cannabis containing THC.
Placebo/THC	Delta-9-THC	Oral placebo followed by inhalation of cannabis containing THC.
CBD/THC	Cannabidiol	Oral CBD 1000mg followed by inhalation of cannabis containing THC.
CBD/THC	Delta-9-THC	Oral CBD 1000mg followed by inhalation of cannabis containing THC.

Primary Outcome Measures

Name	Time	Method
Hopkins Verbal Learning Test	Baseline visit; 20 mins post-THC	Delayed verbal recall
Positive and Negative Syndrome Scale	pre-CBD/placebo administration, and from immediately after THC inhalation until the end of study visit (i.e. 2-3 hours post-THC)	Positive Subscale

Secondary Outcome Measures

Name	Time	Method
White Noise Task	Baseline visit; 50 mins post-THC
Plasma delta-9-tetrahydrocannabinol (THC) concentration	pre-CBD/placebo, 90mins post CBD, and 0mins, 5mins, 15mins, +90mins post-THC
Plasma cannabidiol (CBD) concentration	pre-CBD/placebo, 90mins post CBD, and 0mins, 5mins, 15mins, +90mins post-THC
Plasma 11-COOH-THC concentration	pre-CBD/placebo, 90mins post CBD, and 0mins, 5mins, 15mins, +90mins post-THC
Plasma THC-COOH concentraion	pre-CBD/placebo, 90mins post CBD, and 0mins, 5mins, 15mins, +90mins post-THC
Plasma 6-OH-CBD concentration	pre-CBD/placebo, 90mins post CBD, and 0mins, 5mins, 15mins, +90mins post-THC
State-Trait Anxiety Inventory	pre-CBD/placebo administration, pre-THC and 20mins post-THC	State Scale
Hopkins Verbal Learning Test	Baseline; 20 mins post-THC	Immediate verbal recall
Study drug preference	End of Experiment 2	At the end of the final experimental visit (i.e. 2-3 hours post-THC), participants will be asked to order the two experimental visits according to which drug combination they found most pleasurable.
Advice Taking Task	Baseline visit; 30 mins post-THC
Visual analogue scales	pre-CBD/placebo, 90mins post CBD, pre-THC, and +10mins, +45mins, +90mins post-THC inhalation, and at the end of study visit (i.e. 2-3 hours post-THC)	* Feel drug effect; * Like drug effect; * Want more drug; * Thinking clearly; * Tired; * Excited; * Want to talk; * Anxious; * Relaxed; * Happy; * Irritable; * Suspicious; * Hearing voices; * Dry mouth; * Hungry
Psychotomimetic states inventory	pre-CBD/placebo administration, and at the end of study visit (i.e. 2-3 hours post-THC)
State Social Paranoia Scale	pre-CBD/placebo administration, and at the end of study visit (i.e. 2-3 hours post-THC)
Plasma 11-OH-THC concentration	pre-CBD/placebo, 90mins post CBD, and 0mins, 5mins, 15mins, +90mins post-THC
Digit span	Baseline; 25 mins post-THC	Forward \& Reverse
Positive and Negative Syndrome Scale	pre-CBD/placebo administration, and from immediately after THC inhalation until the end of study visit (i.e. 2-3 hours post-THC)	Negative Subscale
Plasma anandamide concentration	pre-CBD/placebo, 90mins post CBD, and 0mins, 5mins, 15mins, +90mins post-THC
Plasma 2-arachidonoylglycerol concentration.	pre-CBD/placebo, 90mins post CBD, and 0mins, 5mins, 15mins, +90mins post-THC

Trial Locations

Locations (1)

South London and Maudsley NHS Foundation Trust; 🇬🇧 London, United Kingdom