Detection of Cannabis Impairment With an Eye Tracker
- Registration Number
- NCT03813602
- Lead Sponsor
- Centre for Addiction and Mental Health
- Brief Summary
Cannabis is one of the widely used psychoactive substances in the world. With increasing legalization, the prevalence of driving under the influence of cannabis will undoubtedly rise. At present, roadside detection of cannabis intoxication is largely dependent on drug recognition experts who rely on changes in eye movements when impaired. In this regard, use of eye trackers can help to detect impairment in drivers. The purpose of the present study is to determine the feasibility of the use of eye trackers in detecting impairment in participants who smoked a cannabis cigarette.
- Detailed Description
Participants will attend one study session after determination of eligibility. During this session, they will smoke a cannabis cigarette with 12.5% THC prior to driving a simulator. Driving will be assessed prior to smoking cannabis and at 7 time points after smoking cannabis. Eye tracking measures will also be taken while driving after smoking cannabis. Blood will be drawn for determination of levels of the psychoactive substance THC and its metabolites. Saliva tests, urine tests and subjective tests will also be performed at various times points after smoking cannabis.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 10
- Weekly use of cannabis (1 to 4 days per week) confirmed by urine point-of-care testing;
- 19-26 years of age;
- 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 48 hours and cannabis for 72 hours prior to the study session;
- Willing to abstain from all other drugs not prescribed for medical purposes for the duration of the study;
- Provides written and informed consent.
- Urine toxicology screens negative for cannabis upon eligibility assessment;
- Diagnosis of severe medical or psychiatric conditions;
- Females: Pregnancy or breastfeeding;
- Meets criteria for Alcohol or Substance Dependence (current or lifetime) (DSM-IV);
- Is a regular user of medications that affect brain function (i.e., antidepressants, benzodiazepines, stimulants);
- First-degree relative diagnosed with schizophrenia.
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- SINGLE_GROUP
- Arm && Interventions
Group Intervention Description Cannabis sativa Cannabis Sativa a 750 mg cannabis cigarette with 12.5% THC
- Primary Outcome Measures
Name Time Method Change in eye gaze baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours Measures of eye movement with an eye tracker
- Secondary Outcome Measures
Name Time Method Change in blood concentrations of carboxy-tetrahydrocannabinol baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours The levels of the inactive metabolite of THC in blood
Change in blood concentrations of 11-hydroxy-tetrahydrocannabinol baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours The levels of the active metabolite of THC in blood
Change in number of collisions baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours The number of times a car impacts another car while driving the simulator
Change in minimum time to collision on the driving simulator baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours The time needed to collide with the car in front, while driving the simulator
Change in saccades baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours Measures of quick eye movements with an eye tracker
Change in blinking speed baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours How fast the blinking is, measured with an eye tracker
Change in pupil size baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours The diameter of pupils while driving, measured with an eye tracker
Change in eye fixations baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours Measure of where the eye is looking with an eye tracker
Change in blinking rate baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours The number of blinks, measured with an eye tracker
Change in blinking duration baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours The length of time that blinks last, measured with a eye tracker
Change in mean speed on the driving simulator baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours The speed, in km, while driving a driving simulator
Change in standard deviation of speed on the driving simulator baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours The amount of variation in speed while driving the driving simulator
Change in heart rate baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours Vital signs
Change in temperature baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours Vital signs
Change in number of respirations per minute baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours Vital signs
Change in maximum speed on the driving simulator baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours The greatest speed obtained on the driving simulator
Change in standard deviation of lateral position on the driving simulator baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours The amount of weaving while driving the driving simulator
Change in saliva THC detection baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours Detection of THC in saliva
Change in diastolic blood pressure baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours Vital signs
Change in blood concentrations of delta-9-tetrahydrocannabinol baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours The levels of the psychoactive component of cannabis, THC, in blood
Change in systolic blood pressure baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours Vital signs
Change in Subjective cannabis effects with a visual analog scale baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours The amount of liking of cannabis from 0 to 100, with 100 being the greatest value
Trial Locations
- Locations (1)
Center for Addiction and Mental Health
🇨🇦Toronto, Ontario, Canada