Age Differences in the Effects of Cannabis on Simulated Driving (ADCUF)

The Influence of Age on Driving-related Cannabis Effects: Exploring Cannabis Use Frequency and Related Factors

Epidemiological studies suggest that the use of cannabis is associated with an increase in the risk of motor vehicle collisions. It is also known that younger users may be at increased risk for motor vehicle collisions. Further, the frequency with which cannabis is used may be an important variable in determining the effects of cannabis on driving. The purpose of the present study will be to investigate the effects of cannabis on simulated driving in young as compared to middle-aged drivers. Half of the participants will be occasional users of cannabis and half will be frequent users of cannabis.

Study Overview

• Status: Not yet recruiting
• Conditions: Cannabis
• Intervention / Treatment: Drug: Placebos; Drug: Cannabis

Detailed Description

Epidemiological studies have established that the use of cannabis can increase the risk of a motor vehicle collision. A number of variables can influence the effects of cannabis on driving. For example, frequent users of cannabis have been shown to have different cognitive and physiological responses to cannabis as compared to occasional users. In addition, we know that younger drivers are more likely to be involved in motor vehicle collisions after alcohol use as compared to older users. The contribution of age and experience with cannabis on cannabis-mediated effects on driving have yet to be delineated in laboratory studies. The purpose of the present investigation will be to determine whether cannabis has different effects on driving in young, as compared to middle aged, drivers. Half of each age group will be occasional users of cannabis and the other half will be frequent users.

Eligible participants will attend the laboratory for two test sessions; in one session they will smoke a cannabis cigarette and in the other they smoke a placebo cigarette. Participants will drive a driving simulator before and after smoking the cigarette. Blood for measurement of THC and metabolites will also be collected before smoking the cigarette and at a number of times after smoking. Subjective and cognitive tasks will be completed before and after smoking.

It is hoped that the findings of this study will help to inform public perception and policy into the potential effects of cannabis on driving.

• Study Type: Interventional
• Enrollment (Estimated): 128
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Christine Wickens, PhD; Phone Number: 34711 416 535-8501; Email: christine.wickens@camh.ca
• Study Contact Backup: Name: Gina Stoduto; Phone Number: 34499 416 535-8501; Email: gina.stoduto@camh.ca

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5S 2S1
      • Centre for Addiction and Mental Health
      • Contact: Christine Wickens, PhD; Phone Number: 34711 416-535-8501; Email: christine.wickens@camh.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 19 years to 45 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria

• 19-25 or 35-45 years of age;
• Use of smoked cannabis at least once in the past 6 months.
• Use of smoked or vaped cannabis primarily for recreational purposes on up to 1 day per week or on at least 6 days per week in the past 3 months;
• Holds a class G or G2 Ontario driver's licence (or equivalent from another jurisdiction) for at least 12 months;
• Willing to abstain from using alcohol for 24 hours and cannabis for 72 hours prior to Practice and Test Sessions;
• Willing to abstain from all other drugs not prescribed for medical purposes for 48 hours prior to Practice and Test Sessions;
• Resides within Toronto (study site) or can reside with friends/family in Toronto after a Test Session; this area may be extended to the Greater Toronto area if recruitment challenges arise;
• Participant willing to use appropriate contraception until their participation in the study is completed;
• Provides written and informed consent.

Exclusion Criteria

• Use of cannabis primarily for therapeutic purposes, or equally for therapeutic and recreational purposes;
• Diagnosis of medical condition that contraindicates use of cannabis determined by self-report as judged by the Principal Investigator and a study physician; this includes a history of hypersensitivity to cannabinoids smoke, respiratory disease and/or severe cardiovascular, cerebrovascular, renal or liver disease, and bleeding disorders. Smoking cannabis is not recommended for individuals with respiratory diseases, and they will be excluded;
• Diagnosis of psychiatric condition that contraindicates use of cannabis determined by self-report or SCID-5;
• Participants of childbearing potential: Pregnancy (point-of-care test) or breastfeeding;
• Meets criteria for current or lifetime alcohol or other substance use disorder (DSM-5), except tobacco use disorder and caffeine use disorder;
• Is a regular user of medications that affect brain function (based on self-report); this includes concomitant therapy with sedative-hypnotics or other psychoactive drugs
• Use of anti-hypertensives;
• First-degree relative diagnosed with schizophrenia or another psychotic disorder.
• Participation in a past driving study at CAMH (to limit practice effects).
• Participation in a clinical study concurrent with their participation in this study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Age group 19 to 25; Participants will complete two sessions: one where they drive the simulator before and after smoking a placebo cannabis cigarette (<1% THC), the other where they drive the simulator before and after smoking an active cannabis cigarette (15% ± 5% THC).	Drug: Placebos; 750mg cigarette of plant material; Other Names: Dummy; Drug: Cannabis; 750mg cigarette of plant material; Other Names: Marijuana
Other: Age group 35 to 45; Participants will complete two sessions: one where they drive the simulator before and after smoking a placebo cannabis cigarette (<1% THC), the other where they drive the simulator before and after smoking an active cannabis cigarette (15% ± 5% THC).	Drug: Placebos; 750mg cigarette of plant material; Other Names: Dummy; Drug: Cannabis; 750mg cigarette of plant material; Other Names: Marijuana

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Standard deviation of lateral position	A measure of 'weaving' when driving the simulator (meters)	Before cannabis exposure and 30 minutes and 2 hours after cannabis exposure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Verbal Free Recall Task	A measure of the cognitive effects of cannabis (number correct)	Before cannabis exposure and 70 minutes after cannabis
Grooved Pegboard Test	A measure of the cognitive effects of cannabis (performance speed in milliseconds)	Before cannabis exposure and 70 minutes after cannabis
Simple and Choice Reaction Time Tasks	A measure of the cognitive effects of cannabis (milliseconds)	Before cannabis exposure and 70 minutes after cannabis
Vienna Risk-Taking Test	A measure of the amount of risk-taking (latency)	One hour after cannabis exposure
Mean speed	A measure of the average speed while driving the simulator (km/hr)	Before cannabis exposure and 25 minutes and 2 hours after cannabis exposure
Standard deviation of speed	A measure of the variability in speed while driving the simulator (km/hr)	Before cannabis exposure and 25 minutes and 2 hours after cannabis exposure
Maximum speed	A measure of the greatest speed obtained while driving the simulator (in km/hr)	Before cannabis exposure and 25 minutes and 2 hours after cannabis exposure
Following distance	A measure of the distance between the car being driven and the car in front (meters)	Before cannabis exposure and 25 minutes and 2 hours after cannabis exposure
Braking latency	A measure of the time it takes to move the foot from the gas pedal to the brake when a stop sign is encountered (seconds)	Before cannabis exposure and 25 minutes and 2 hours after cannabis exposure
Number of collisions	The number of collisions while driving the simulator (total number)	Before cannabis exposure and 25 minutes and 2 hours after cannabis exposure
Blood concentration of delta-9-tetrahydrocannabinol (THC)	A measure of the psychoactive component of cannabis in blood (ng/ml)	Before cannabis exposure and 25 minutes and 2 hours after cannabis
Blood concentration of carboxy-tetrahydrocannabinol (THC-COOH)	A measure of the inactive metabolite of cannabis in blood (ng/ml)	Before cannabis exposure and 25 minutes and 2 hours after cannabis
Blood concentration of 11-hydroxy-tetrahydrocannabinol (11-OH-THC)	A measure of the active metabolite of cannabis in blood (ng/ml)	Before cannabis exposure and 25 minutes and 2 hours after cannabis
Systolic blood pressure	A vital sign (mmHg)	Before cannabis exposure and 5, 15, 25 minutes and 1, 2, 3, 4 and 5 hours after cannabis
Diastolic blood pressure	A vital sign (mmHg)	Before cannabis exposure and 5, 15, 25 minutes and 1, 2, 3, 4 and 5 hours after cannabis
Heart rate	A vital sign (beats/minute)	Before cannabis exposure and 5, 15, 25 minutes and 1, 2, 3, 4 and 5 hours after cannabis
Visual Analog Scales such as 'I feel this effect', 'I like this drug effect', 'I feel the good effects'	A measure of the subjective effects of cannabis (on a scale of 0 to 100, where is 100 is the strongest level of agreement)	Before cannabis exposure and 5, 15, 25 minutes and 1, 2, 3, 4 and 5 hours after cannabis
Trail Making Test	A measure of the cognitive effects of cannabis (performance speed in seconds)	Before cannabis exposure and 70 minutes after cannabis

Collaborators and Investigators

• Sponsor: Centre for Addiction and Mental Health
• Investigators: Principal Investigator: Christine Wickens, PhD, Centre for Addiction and Mental Health

Study record dates

Study Major Dates

• Study Start (Estimated): March 15, 2024
• Primary Completion (Estimated): March 1, 2027
• Study Completion (Estimated): March 1, 2027

Study Registration Dates

• First Submitted: March 26, 2020
• First Submitted That Met QC Criteria: March 26, 2020
• First Posted (Actual): March 30, 2020

Study Record Updates

• Last Update Posted (Actual): March 8, 2024
• Last Update Submitted That Met QC Criteria: March 6, 2024
• Last Verified: March 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Mental Disorders; Chemically-Induced Disorders; Substance-Related Disorders; Marijuana Abuse
• Other Study ID Numbers: 048/2019

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No