A Phase 2 interventional study of Low-dose THC administration via IV and High-Dose THC administration via IV in None Volunteer, sponsored by King's College London. Not yet recruiting at 1 site in United Kingdom. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-16.
Sponsored by King's College London · Phase 2, Interventional, and Basic science
The study team is studying how delta-9-tetrahydrocannabinol (THC) - the component of cannabis that is responsible for "getting people feeling high" - influences how people think about the behaviour of others and a variety of other experiences. The study team is investigating these processes in healthy adults. The study team uses computer-based tasks and questionnaires to understand how people make conclusions about other people's intentions under different circumstances.
In this study, the study team uses a placebo-controlled within-participant study design with three different conditions: (i) 1mg/ml THC administration, (ii) 2mg/ml THC administration, and (iii) placebo (Saline) administration, all via an intravenous IV. The study is within-participants, meaning that every participant will experience all three conditions. The study is double blind, meaning that neither the researcher nor the participant will know what condition they will be in on a given study visit. The sequence of conditions is balanced across participants.
530 studies on the registry are indexed under Marijuana Abuse; 114 are open to participants now.
This study's planned enrollment of 100 is above the median of 60 across 431 interventional studies indexed under Marijuana Abuse.
Browse Marijuana Abuse studies →King's College London is the lead sponsor of 519 studies on the registry; 126 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Application of saline solution instead of THC solution intravenously over 20min
Drug: Saline administration via IV
Application of 1mg THC /ml solution intravenously over 20min
Drug: Low-dose THC administration via IV
Application of 2mg THC /ml solution intravenously over 20min
Drug: High-Dose THC administration via IV
The study drug for this study is synthetically derived delta-9-tetrahydrocannabinol (THC, International Non-proprietary Name: Dronabinol). THC Active Pharmaceutical Ingredient (API) is provided by Purisys LLC (CDMO), Georgia, USA; and formulated into a solution for intravenous injection by Hybrid Pharma, Florida USA. As detailed in D'Souza et al., 2004, THC is dissolved in 95% ethanol (Agurell et al. 1986) to yield a concentration of 12 mg/ml stock solution which was then passed through a polymer filter, subjected to sterility and pyrogenicity testing, and assayed by gas chromatography mass spectrometry to confirm its concentration and stored at room temperature for future use. Hybrid Pharma will provide 5 ml vials of active drug and matched placebo (ethanol solution without THC). In the high-dose condition, 1mg/ml will be administered over 20min via IV.
The study drug for this study is synthetically derived delta-9-tetrahydrocannabinol (THC, International Non-proprietary Name: Dronabinol). THC Active Pharmaceutical Ingredient (API) is provided by Purisys LLC (CDMO), Georgia, USA; and formulated into a solution for intravenous injection by Hybrid Pharma, Florida USA. As detailed in D'Souza et al., 2004, THC is dissolved in 95% ethanol (Agurell et al. 1986) to yield a concentration of 12 mg/ml stock solution which was then passed through a polymer filter, subjected to sterility and pyrogenicity testing, and assayed by gas chromatography mass spectrometry to confirm its concentration and stored at room temperature for future use. Hybrid Pharma will provide 5 ml vials of active drug and matched placebo (ethanol solution without THC). In the high-dose condition, 2mg/ml will be administered over 20min via IV.
Saline will be administered intravenously rather than THC
Harmful intent attribution
Participants will play a task (Sharing Game), where they have make intent attributions to an agent they are interacting with. The attribution will be made on a visual analogue scale ranging from 1 to 100 with higher numbers representing more harmful intent attribution. The outcome variable will be estimated using a computational model that takes more aspects of the task into account
Time frame: Study day 1 to 4, max. within three months, i.e. baseline visit, experimental visit 1 - after intervention and task, experimental visit 2 - after intervention and task, experimental visit 3 - after intervention and task
Social behaviours and decision making under uncertainty as measured by the Sharing Game and similar games.
participants are engaging in a set of tasks that measure inference and decision making. Outcome measures are estimated using a computational model that takes other aspects of the task and decision making into account as is custom in computational modeling of behaviour in cognitive psychology and computational psychiatry.
Time frame: Study day 1 to 4, max. within three months, i.e. baseline visit, experimental visit 1 - after intervention and task, experimental visit 2 - after intervention and task, experimental visit 3 - after intervention and task
Immediate recall on the HVLT-R
Hopkins verbal learning task - Revised (HVLT-R) is a part of the MATRICS Consensus Cognitive Battery (PAR, Inc FL 33549). The first phase of the test is an immediate recall phase where participants are read a list of 12 words across three trials (nouns from three taxonomic categories) and participants have to recall the words immediately after. There are 5 validated versions of the HVLT-R and the order of test versions will be randomised for each participant to prevent potential order effects. The more words recalled the higher the score.
Time frame: Study day 1 to 4, max. within three months, i.e. baseline visit, experimental visit 1 - before intervention, experimental visit 2 - before intervention and task, experimental visit 3 - before intervention and task
Delayed recall on the HVLT-R
Hopkins verbal learning task - Revised (HVLT-R) is a part of the MATRICS Consensus Cognitive Battery (PAR, Inc FL 33549). It consists of an immediate recall phase where participants are read a list of 12 words across three trials (nouns from three taxonomic categories). This is followed by a delayed free recall phase between 20-25 minutes after completion of the immediate recall phase where then participant is asked to recall as many of the words from the list as they can remember. Repetitions and intrusions (words recalled not part of the original list) will also be recorded for each trial. There are 5 validated versions of the HVLT-R and the order of test versions will be randomised for each participant to prevent potential order effects. Delayed recall is measured by how many words are remembered after the delayed free recall phase. More words remembered result in higher scores.
Time frame: Study day 1 to 4, max. within three months, i.e. baseline visit, experimental visit 1 - before intervention, experimental visit 2 - before intervention and task, experimental visit 3 - before intervention and task
Working memory performance (Digit Span)
Forward and reverse digit span refers to the longest list of numbers the participant can correctly recall, both in forward and backward order. The task starts at the length of four digits (three for backward) and is increased by one digit for each successful trial. The task is ended when the participant fails to give the correct order after two consecutive attempts. The further participants get in the test the better working memory performance.
Time frame: Study day 1, i.e. Baseline visit
Paranoia score (SPSS)
State social paranoia scale (SSPS) is a 10-item instrument which measures persecutory thoughts. The persecutory items (e.g. 'someone had bad intentions towards me') are presented among 10 neutral items and scored on a 5-point scale (do not agree - totally agree).
Time frame: Study day 1 to 4, max. within three months, i.e. Baseline visit, Experimental visit 1 - before intervention, Experimental visit 2 - before intervention, Experimental visit 3 - before intervention
Positive psychotic symptoms (PANSS-P)
Positive and negative syndrome scale - positive subscale (PANSS-P) is the most common scale to measure psychotic symptoms and commonly used in schizophrenia research. The PANSS is an investigator rated scale and is scored following a semi-structured interview. In this study only the positive subscale will be used, which include the following symptoms: delusions, conceptual disorganisation, hallucinations, hyperactivity, grandiosity, suspiciousness and hostility. The symptoms are scored on a 7-point scale from absent-severe.
Time frame: Study day 1 to 4, max. within three months, i.e. Baseline visit, Experimental visit 1 - before intervention, Experimental visit 2 - before intervention, Experimental visit 3 - before intervention
Mood States
Visual analogue scales (VAS) consist of words which describe feeling states and a 100mm horizontal line on which the participant indicates with a vertical line how much of that feeling they have experienced in the moment. The scale ranges from "Not at all" (0mm) to "As much as could possibly be" (100mm).
Time frame: Study day 2 to 4, max. within three months, i.e. Experimental visit 1 - before and after intervention, Experimental visit 2 - before and after intervention, Experimental visit 3 - before and after intervention
Paranoia
Visual analogue scales (VAS) consist of words which describe feeling states and a 100mm horizontal line on which the participant indicates with a vertical line how much of that feeling they have experienced in the moment. The scale ranges from "Not at all" (0mm) to "As much as could possibly be" (100mm). Six paranoia VAS from Freeman et al., (2015) will also be included: "Right now I feel suspicious of other people," "Right now I feel that people want to harm me," "Right now I feel like people want to upset me," "Right now I feel like people are against me," "Right now I am thinking that others are trying to persecute me," and "Right now I feel like people are being hostile towards me".
Time frame: Study day 2 to 4, max. within three months, i.e. Experimental visit 1 - before and after intervention, Experimental visit 2 - before and after intervention, Experimental visit 3 - before and after intervention
Heartrate related markers
Heart beat will be measured using a standard pulse-oximeter. Systolic blood pressure peaks will be used as a proxy for the R-peak and Inter-beat-intervals will be calculated based on consecutive systolic blood pressure peaks. Heart rate variability will be operationalized as RMSSD based on these inter-beat-intervals.
Time frame: Study day 1 to 4, max. within three months, i.e. Baseline visit - before and during task, Experimental visit 1 - before and during task, Experimental visit 2 - before and during task, Experimental visit 3 - before and during task
Plan to share: Yes — In the informed consent, participants consent for their fully anonymized data to be shared with other researchers and collaborators. Outcome measures as specified in "Outcome measures" section.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report, Analytic code
No publications or documents are linked to this record.
Start is estimated for Nov 2026; primary completion for Sep 2028, 22 months later.
Of 39 non-industry phase 2 interventional studies under Marijuana Abuse, half reached primary completion within 41 months of starting (the median), counting those still running; a quarter within 27 and three quarters within 53. This study's planned 22 months is below that.
Counting every sponsor, half of 46 studies reached it within 40 months; a quarter within 21 and three quarters within 53.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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