Dose-response of Cannabis and Driving

Cognitive Impairment Clinical Trial

Official title:

Dose-dependent Effects of Smoked Cannabis on Simulated Driving Performance

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03656029
• Other study ID #: 007-2018
• Status: Completed
• Phase: Phase 2
• Start date: June 4, 2021
• Est. completion date: June 14, 2022

Study information

• Verified date: October 2022
• Source: Centre for Addiction and Mental Health
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Epidemiological studies have established a link between collisions while driving and cannabis use. With the changing legal landscape around cannabis, there is much interest in determining per se limits of cannabis while driving. The present study will evaluate driving on a driving simulator after smoking placebo or cannabis with 3 different levels of THC. THC is the active component in cannabis and blood, urine and oral fluid levels of THC will be correlated with driving impairment.

Description:

Participants will attend the laboratory for 4 separate sessions, separated by about a week. In each session, participants will receive one of 3 doses of smoked cannabis or a placebo. Participants will not know which dose they are receiving. Participants will complete questionnaires, do cognitive tests and drive on a driving simulator before and after smoking the cannabis or placebo cigarette. Blood, urine and oral fluid will be collected throughout the 7-8 hour session to determine levels of THC and its metabolites. These values will be correlated with measures of driving impairment.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 36
• Est. completion date: June 14, 2022
• Est. primary completion date: June 14, 2022
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 19 Years to 45 Years

Eligibility

Inclusion Criteria:

• Near daily use of cannabis (1-5 days/week) confirmed by self-report and urine screening
• Has held a class G2 or G licence (or equivalent from another jurisdiction) for at least 12 months
• Willing to abstain from using cannabis for 72 hours prior to each practice or test session
• Willing to abstain from alcohol for 48 hours prior to each session, and to abstain from all other drugs not medically required for the duration of the study (beginning 48 hours prior to the practice session)
• Provides written and informed consent

Exclusion Criteria:

• Diagnosis of severe medical or psychiatric condition
• Meets criteria for current or lifetime alcohol or other substance use disorder, except tobacco use disorder and caffeine use disorder
• Regular user of medication that may affect cognitive functioning and/or driver performance
• Family history of schizophrenia or other psychotic disorder
• Pregnant, looking to become pregnant, or breastfeeding

Related Conditions & MeSH terms

• Abuse Cannabis
• Cognitive Impairment
• Driving Impaired
• Marijuana Abuse

Intervention

Drug:
• Cannabis
Participants will smoke as much of the cigarette as they wish
• Placebo
Participants will smoke a placebo cigarette

Locations

Country	Name	City	State
Canada	Center for Addiction and Mental Health	Toronto	Ontario

Sponsors (1)

Lead Sponsor	Collaborator
Centre for Addiction and Mental Health

Country where clinical trial is conducted

Canada, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Mean speed	Speed of driving the simulator	Change in speed of driving between the time before smoking the cigarette and either 30 or 90 minutes after smoking the cigarette
Secondary	Standard deviation of lateral position	Driving measures	Change in measure from before smoking the cigarette to either 30 or 90 minutes after smoking
Secondary	reaction time	Driving measures	Change in measure from before smoking the cigarette to either 30 or 90 minutes after smoking
Secondary	Blood concentrations of THC and metabolites	Blood will be taken to determine how much THC entered the blood	Change from before smoking cigarette to various time points after smoking: 5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 2hours, 3 hours, 4 hours, 5 hours and 6 hours
Secondary	Oral fluid concentrations of THC and metabolites	Participants will provide oral fluid to determine how much THC is in the oral fluid	Change from levels before smoking to 4 time points after smoking: 30 minutes, 90 minutes, 2 hours and 6 hours
Secondary	Systolic and Diastolic Blood pressure	Vital signs	Change from before smoking to a number of time points after smoking: 5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 2hours, 3 hours, 4 hours, 5 hours and 6 hours
Secondary	Heart rate	Vital signs	Change from before smoking to a number of time points after smoking: 5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 2hours, 3 hours, 4 hours, 5 hours and 6 hours
Secondary	Respirations	Vital signs	Change from before smoking to a number of time points after smoking: 5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 2hours, 3 hours, 4 hours, 5 hours and 6 hours
Secondary	Temperature	Vital signs	Change from before smoking to a number of time points after smoking: 5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 2hours, 3 hours, 4 hours, 5 hours and 6 hours
Secondary	Visual Analog Scales	Tests designed to assess the degree of subjective effects of the drug. The questions will be scored on a scale from 0 to 100 and will consist of: 'I like this drug effect', 'this feels like cannabis', 'I feel this effect', 'I feel this high', 'I feel the good effects', 'I feel the bad effects', 'I feel the rush'	Change from before smoking to a number of time points after smoking: 5 minutes, 15 minutes, 30 minutes, 60 minutes, 90 minutes, 2hours, 3 hours, 4 hours, 5 hours and 6 hours
Secondary	Verbal free recall test	Test of memory: Participants will be asked to recall words that are read from a list	Change from pre-smoking levels to those observed 60 minutes after smoking
Secondary	Useful field of view	A computer test for visual processing speed, selective and divided attention	Change from pre-smoking levels to those observed 60 minutes after smoking