Examine the Feasibility of a Standardized Field Test for Marijuana Impairment: Laboratory Evaluations

Study Overview
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Brief Summary
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Marijuana is one of the most widely used substances. This study will characterize the persistence of cannabis' (CNB's) acute effects on cognitive test performance and simulated driving over a several hour time period. The data obtained from simulated driving, cognitive tests, and biological assays of THC will be used in analyses aimed at identifying what tests or combination of tests predict both recent use and driving impairment risk. Eligible participants will undergo a full day screening visit, if still eligible they will come to Hartford Hospital in Hartford, Connecticut to take part in the full study. Participation requires overnight stays between each of the five study visits. On each of the study days participants are dosed with either a low dose of THC marijuana, a high dose of THC marijuana or placebo marijuana, (the low and high doses are repeated once each, order in which the study drug is given is double blind and chosen at random.)

Detailed Description
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This responds to NHTSA's request with a proposal to increase our understanding of smoked cannabis' (CNB's) acute effects on cognition and simulated driving performance, the persistence of these deficits over the hours after use, and the influence of prior experience with CNB on these effects. The project also will link an extensive literature on CNB's effects on laboratory cognitive tests to simulated driving performance for the first time, providing a crucial validation of CNB's neurofunctional effects identifying maximally relevant candidate measures for field sobriety tests. To this goal, the proposed study was based upon a careful and thorough review of the scientific literature describing CNB effects on cognitive test performance and driving, as well as current state-of-knowledge on the sensitivity of biological assays for identifying recent CNB use. The study will carefully characterize the persistence of CNB's acute effects on cognitive test performance and driving over a several-hour time span. This will allow us to identify the point at which any effects of CNB intoxication on cognitive tests and driving performance cannot be distinguished from normal, i.e., the first step towards establishing standards for legal and social policy. The data obtained from simulated driving, cognitive tests, and biological assays of THC will be used in analyses aimed at identifying what tests or combination of tests predict both recent use and driving impairment risk. Participants

Official Title
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Examine the Feasibility of a Standardized Field Test for Marijuana Impairment: Laboratory Evaluations

Conditions
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Marijuana Impairment

Intervention / Treatment
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* Drug: Low Dose THC Marijuana
* Drug: High Dose THC Marijuana
* Drug: Placebo Marijuana


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Must have a current driver's license Have used marijuana before Right handed Exclusion Criteria: Females who are pregnant or breast feeding Any serious medical, or neurological disorder Any psychiatric disorder No major head traumas

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Regular Users<br>People who use marijuana regularly will be given a low dose THC marijuana, high dose THC marijuana and placebo marijuana, in a randomized order, at the five study visits. | Drug: Low Dose THC Marijuana<br>* Dosing via vaporized marijuana using a lower concentration of THC, participants receive this dose on two of the five study visits.<br>* Other names: THC, Cannabis;Drug: High Dose THC Marijuana<br>* Dosing via vaporized marijuana using a higher concentration of THC, participants receive this dose on two of the five study visits.<br>* Other names: THC, Cannabis;Drug: Placebo Marijuana<br>* Dosing via vaporized marijuana with no THC, participants receive this dose on one of the five study visits.<br>* Other names: THC, Cannabis;|
| Experimental: Occasional Users<br>People who use marijuana occasionally will be given a low dose THC marijuana, high dose THC marijuana and placebo marijuana, in a randomized order, at the five study visits. | Drug: Low Dose THC Marijuana<br>* Dosing via vaporized marijuana using a lower concentration of THC, participants receive this dose on two of the five study visits.<br>* Other names: THC, Cannabis;Drug: High Dose THC Marijuana<br>* Dosing via vaporized marijuana using a higher concentration of THC, participants receive this dose on two of the five study visits.<br>* Other names: THC, Cannabis;Drug: Placebo Marijuana<br>* Dosing via vaporized marijuana with no THC, participants receive this dose on one of the five study visits.<br>* Other names: THC, Cannabis;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Marijuana induced performance changes on Cogstate 1-back/2-back task. | The Cogstate 1-back/2-back task assesses working memory, it will be administered prior to dosing and at various time points after dosing. | Baseline and post drug administration at: 10 min; 1.5 hours 2.5 hours; 4.5 hours; 6.5 hours | 
| Marijuana induced performance changes on Cogstate Card Learning. | The Cogstate Card Learning task assesses visual memory, it will be administered prior to dosing and at various time points after dosing. | Baseline and post drug administration at: 10 min; 1.5 hours 2.5 hours; 4.5 hours; 6.5 hours | 
| Marijuana induced performance changes on Cogstate Groton Maze Learning task. | The Cogstate Groton Maze Learning task assesses spatial learning and memory, it will be administered prior to dosing and at various time points after dosing. | Baseline and post drug administration at: 10 min; 1.5 hours 2.5 hours; 4.5 hours; 6.5 hours | 
| Marijuana induced performance changes on Cogstate Social/Emotional Cognition task. | The Cogstate Social/Emotional Cognition task assesses emotional processing, it will be administered prior to dosing and at various time points after dosing. | Baseline and post drug administration at: 10 min; 1.5 hours 2.5 hours; 4.5 hours; 6.5 hours | 
| Marijuana induced performance changes on Alertmeter. | The Alertmeter task assess visual judgment and alertness, it will be administered prior to dosing and at various time points after dosing. | Baseline and post drug administration at: 10 min; 1.5 hours 2.5 hours; 4.5 hours; 6.5 hours | 
| Marijuana induced performance changes on the Time Estimation Task. | The Time Estimation Task assesses timing, it will be administered prior to dosing and at various time points after dosing. | Baseline and post drug administration at: 10 min; 1.5 hours 2.5 hours; 4.5 hours; 6.5 hours | 
| Marijuana induced performance changes on the Stop Signal Reaction Time task. | The Stop Signal Reaction Time Task assesses inhibitory processing, it will be administered prior to dosing and at various time points after dosing. | Baseline and post drug administration at: 10 min; 1.5 hours 2.5 hours; 4.5 hours; 6.5 hours | 
| Marijuana induced performance changes on the Critical Tracking Task. | The Critical Tracking Task assesses hand eye coordination and visuomotor tracking, it will be administered prior to dosing and at various time points after dosing. | Baseline and post drug administration at: 10 min; 1.5 hours 2.5 hours; 4.5 hours; 6.5 hours | 
| Marijuana induced performance changes on the ANAM Pursuit Tracking Task. | The ANAM Pursuit Tracking Task assesses hand eye coordination, it will be administered prior to dosing and at various time points after dosing. | Baseline and post drug administration at: 10 min; 1.5 hours 2.5 hours; 4.5 hours; 6.5 hours | 
| Marijuana induced performance changes on the Finger to Nose Task. | The Finger to Nose Task assesses general motor coordination, it will be administered prior to dosing and at various time points after dosing. | Baseline and post drug administration at: 10 min; 1.5 hours 2.5 hours; 4.5 hours; 6.5 hours | 
| Marijuana induced performance changes on the One Leg Stand Task. | The One Leg Stand Task assesses general motor coordination, it will be administered prior to dosing and at various time points after dosing. | Baseline and post drug administration at: 10 min; 1.5 hours 2.5 hours; 4.5 hours; 6.5 hours | 
| Marijuana induced performance changes on the Line Walking/Months Backwards Task. | The Line Walking/Months Backwards Task assesses general motor coordination plus distraction, it will be administered prior to dosing and at various time points after dosing. | Baseline and post drug administration at: 10 min; 1.5 hours 2.5 hours; 4.5 hours; 6.5 hours | 
| Marijuana induced performance changes on the Time Reproduction Task. | The Time Reproduction Task assesses general motor coordination plus timing, it will be administered prior to dosing and at various time points after dosing. | Baseline and post drug administration at: 10 min; 1.5 hours 2.5 hours; 4.5 hours; 6.5 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in concentration of THC/metabolites in blood samples. | Blood samples with be collected at 8 times throughout each day to assess for changes of THC and its metabolite levels. | Baseline and post drug administration at: 5 min, 20 min, 1 hr 10 min, 1 hr 45 min, 2 hrs 30 min, 4 hrs, and 6 hrs 30 min. | 
| Change in concentration of THC/metabolites in oral fluid tested using Draeger Drug Detection Kits. | Oral fluid samples with be collected at 8 times throughout each day to assess for changes of THC and its metabolite levels. | Baseline and post drug administration at: 5 min, 20 min, 1 hr 10 min, 1 hr 45 min, 2 hrs 30 min, 4 hrs, and 6 hrs 30 min. | 
| Change in concentration of THC/metabolites in oral fluid tested using Quantisal Oral Fluid Collection devices. | Oral fluid samples with be collected at 8 times throughout each day to assess for changes of THC and its metabolite levels. | Baseline and post drug administration at: 5 min, 20 min, 1 hr 10 min, 1 hr 45 min, 2 hrs 30 min, 4 hrs, and 6 hrs 30 min. | 
| Change in performance on simulated driving Road Tracking Task. | The Road Tracking Task measures operational control of the vehicle. Operational control is measured by standard deviation of lane position from the center point of the lane. | Post drug administration at: 1 hour, 3 hours and 5 hours | 
| Change in performance on simulated driving Car Following Task. | The Car Following Task measures tactical control of the vehicle. Tactical control of the vehicle is measured by following distance from a lead vehicle. | Post drug administration at: 1 hour, 3 hours and 5 hours | 
| Change in performance on simulated driving Gap Acceptance Task. | The Gap Acceptance Task measures strategic control of the vehicle. Strategic control of the vehicle is measured by size of headway gaps that the participant chooses in pulling out into oncoming traffic to overtake a stopped car. | Post drug administration at: 1 hour, 3 hours and 5 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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marijuana, THC, cannabis, driving, impairment, intoxication