Do Adolescents and Adults Differ in Their Acute Subjective, Behavioural and Neural Responses to Cannabis, With and Without Cannabidiol?
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- University College, London
- Enrollment
- 48
- Locations
- 1
- Primary Endpoint
- Psychotomimetic effect
Study Overview
Brief Summary
The acute effects of cannabis may differ between adolescents and adults. Furthermore, these effects may be tempered by the presence of cannabidiol. This double-blind, placebo-controlled, crossover experiment investigates the acute effects of cannabis (with and without cannabidiol) on subjective effects, behavioural responses and neural functioning in 16-17 year-olds and 26-29 year-olds who regularly use cannabis (0.5-3 days per week).
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover
- Primary Purpose
- Basic Science
- Masking
- Double (Participant, Investigator)
Masking Description
Double-blind
Eligibility Criteria
- Ages
- 16 Years to 29 Years (Child, Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Adolescents: Aged 16-17
- •Adults: Aged 26-29 years
- •Self-reported cannabis use between 0.5 and 3 days/week, averaged over the last 3 months
- •Adults: Body mass index (BMI) between 18.5 and 29.9
- •Adolescents: BMI between 2nd percentile and 98th percentile
- •Self-reported ability to consume approximately half a typical joint of cannabis by themselves within 20 minutes
- •Willing to be cannulated and have four blood samples taken at every acute session
- •Right-handed
Exclusion Criteria
- •Females: Pregnant or breast-feeding
- •Adults: Before the age of 18, had a period of 3 or more months when cannabis was used once per week or more frequently.
- •Severe cannabis use disorder (DSM-5)
- •Illicit drug use of any specific drug more than twice per month, averaged over the last 3 months
- •Receiving treatment (pharmacological or psychological) for a mental health problem within the last month
- •Lifetime psychosis
- •Lifetime psychosis of any immediate family member
- •Hypertension (systolic > 160 or diastolic > 100)
- •Dependent on tobacco or vaping nicotine (> 1 on the Heaviness of Smoking Index)
- •Currently taking a psychotropic medication that will likely affect dependent variables or interact with cannabis
- •Any physical or mental health condition, any medication, or any treatment, that the study doctor considers to be an exclusion
- •MRI contraindications
- •Significant asthma or respiratory problems - severity judged clinically
- •Self-reported moderate/severe acute unpleasant effects from cannabis which occur often or always
- •Positive alcohol breathalyser reading at any acute session (rearrange session)
- •Self-reported use of alcohol within 24 hours at any acute session (rearrange session)
- •Self-reported use of illicit drugs (including cannabis) within 72 hours at any acute session (rearrange session)
- •Positive saliva drug screen at any acute session (rearrange session)
Arms & Interventions
THC condition
THC condition: Cannabis with delta-9-tetrahydrocannabinol (THC) and no cannabidiol (CBD). 0.107mg/kg of THC. A 75kg person receives 8mg of THC.
Route of administration: vaporised and inhaled.
Frequency: once.
Duration: inhaled in < 18 minutes.
Intervention: Cannabis with delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) (Drug)
THC+CBD condition
THC+CBD condition: Cannabis with THC and CBD (i.e. THC+CBD condition). 0.107mg/kg of THC and 0.320mg/kg of CBD. A 75kg person receives 8mg of THC and 24mg of CBD.
Route of administration: vaporised and inhaled.
Frequency: once.
Duration: inhaled in < 18 minutes.
Intervention: Cannabis with THC without CBD (Drug)
PLA condition
PLA condition: Placebo cannabis with no THC or CBD.
Route of administration: vaporised and inhaled.
Frequency: once.
Duration: inhaled in < 18 minutes.
Intervention: Placebo cannabis (Drug)
Outcomes
Primary Outcomes
Psychotomimetic effect
Time Frame: Measured once, 2 hours after the start of drug administration, on each drug condition
Measured by total Psychotomimetic States Inventory (PSI) score
Strength of subjective drug effect
Time Frame: Measured 20 minutes after the start of drug administration, on each drug condition
Measured by self-reported 'feel drug effect', rated from 0 (not at all) to 10 (extremely)
Verbal episodic memory
Time Frame: Measured once, 2 hours after the start of drug administration, on each drug condition
Measured by delayed prose recall performance
Secondary Outcomes
- Heart rate(Measured -30 minutes, 20 minutes, 30 minutes, 2 hours, and 2 hours & 40 minutes after the start of drug administration, on each drug condition)
- Blood pressure(Measured -30 minutes, 20 minutes, 30 minutes, 2 hours, and 2 hours & 40 minutes after the start of drug administration, on each drug condition)
- Magnetic resonance spectroscopy(Measured 1 hour & 30 minutes after the start of drug administration, on each drug condition)
- Self-reported subjective effects(Measured -30 minutes, 20 minutes, 30 minutes, 2 hours, and 2 hours & 40 minutes after the start of drug administration, on each drug condition)
- Exogenous and endogenous cannabinoid levels in plasma(Measured -30 minutes, 20 minutes, 30 minutes, and 2 hours & 40 minutes after the start of drug administration, on each drug condition)
- Functional magnetic resonance imaging (fMRI) measured neural correlates(Measured between 40 minutes and 1 hour & 20 minutes after the start of drug administration, on each drug condition)
- Positive and negative syndrome scale(Measured 2 hours & 40 minutes after the start of drug administration, on each drug condition)
- Visual attentional bias to cannabis and food stimuli(Measured 2 hours & 10 minutes after the start of drug administration, on each drug condition)
- Effort-related decision-making (i.e. amotivation)(Measured 2 hours & 20 minutes after the start of drug administration, on each drug condition)
- Dissociative states scale(Measured 2 hours & 40 minutes after the start of drug administration, on each drug condition)
- Pleasure processing(Measured 2 hours & 30 minutes after the start of drug administration, on each drug condition)