Evaluation of an Eye Tracking Sensor to Detect Cannabis Impairment

The proposed project is a single-visit clinical laboratory study to evaluate the initial efficacy of an eye tracking sensor to detect cannabis-related impairment.

Participants will be experienced but not frequent cannabis users without evidence of heavy alcohol or illicit drug use or other physical or mental health illness. Participants will come in for one screening visit, and those who consent, are eligible, and enroll will complete one experimental laboratory session involving smoking of 50% of 1 active (approximately 4.0% THC) cannabis cigarette. Assessments will be collected after-cannabis smoking up to 4 hours. Participants will be sent home from the laboratory via taxi.

• Virtual Reality Eye Tracking after smoking Cannabis - HTC Vive Pro-Eye (Device): Device measures smooth eye pursuit and response to light flash after pt smokes cannabis
• Cannabis cigarette - 4.0% THC (Drug), also known as Marijuana: smoked cannabis 4.0% THC

Primary outcomes

• Change from baseline in Pupil Dilation [Before and after smoking (up to 240 minutes)]: Change in pupil dilation in different lights will be measured by the eye tracking sensor
• Change from baseline in Gaze Nystagmus [Before and after smoking (up to 240 minutes)]: Change in Gaze Nystagmus will be measured by the eye tracking sensor
• Change from baseline in Lack of Convergence [Before and after smoking (up to 240 minutes)]: Change in Lack of Convergence will be measured by the eye tracking sensor

Secondary outcomes

• Plasma THC [Before and after smoking (9 timepoints up to 240 minutes post smoking)]: Plasma concentration before and after smoking
• Change from baseline in Cannabis Subjective Effects [Before and after smoking (up to 240 minutes post smoking)]: Scores for the question "do you feel a drug effect" are measured on a 0-100 point visual analogue scale to measure change in marijuana intoxication across timepoints.
• Change from baseline in Four Choice Reaction Time Task [Before and after smoking (up to 240 minutes post smoking)]: Will assess changes in psychomotor/cognitive performance known to be sensitive to the acute effects of smoked cannabis.
• Change from baseline in Digit Symbol Substitution Task [Before and after smoking (up to 240 minutes post smoking)]: Will assess changes in psychomotor/cognitive performance known to be sensitive to the acute effects of smoked cannabis.

Sex: All, ages: 18 Years to 55 Years, accepts healthy volunteers

Inclusion Criteria:

1. Willing to sign a confidentiality agreement stating the will not discuss study specifics, information or materials presented to them in the study with those not involved in the study;
2. Currently living in Baltimore City or Baltimore County, MD, or Investigator discretion;
3. Able to read, understand, and sign informed consent;
4. 18-55 years old;
5. Self-reports lifetime smoking of cannabis at least 10 times without any negative side effects;
6. Self-reports past-year smoking of cannabis at least 1 time but no more than 2 days per week on average;
7. Designation of Medically Healthy for Research by the Study Physician.
8. Agree to abstain from consuming alcohol for 10 hours and marijuana for 72 hour prior to the study visit

Exclusion Criteria:

1. BAC > 0.020% as measured by alcohol breathalyzer;
2. Meets DSM-5 criteria for any current Axis I disorder other than mild or moderate Cannabis Use Disorder;
3. Self-reported current desire to stop cannabis use, defined as 7 or greater on an 11-rung (scale of 0-10) on the Contemplation Ladder assessment;
4. Self-reported current asthma, chronic obstructive pulmonary disease, hypertension, cardiovascular disease or any other medical illness that precludes participation based on the clinical judgment of the Study Physician and Investigative Team;
5. Has difficulties with blood draws or poor venous access;
6. History of blood donation in the past 30 days or receiving blood products within the past 2 months prior to any experimental visit;
7. Investigator discretion due to self-reported use of medical cannabis or using cannabis for self-medication;
8. Among females, current pregnancy or lactation or attempting to get pregnant, or at risk of becoming pregnant, as defined as being sexually active with a male partner and not willing to use a reliable form of contraception;
9. Investigator discretion due to use of caffeine, over-the-counter (OTC) drugs, prescription drugs, alcohol, or physical/mental health history;
10. Positive urine drug screen for drugs included on the urine drug panel other than cannabis;
11. Acute illness (such as cold or flu) which will require participant to be rescheduled, if authorized by study PI;
12. Vital signs thought to be clinically significant by licensed medical professional;
13. Self-reported history or medical evidence of prior intravenous drug use; and
14. Investigator discretion due to medical, mental health, or substance use history.
15. Presence of implanted devices in the body (pacemaker etc)
16. Previously reported negative effects from the use of VR goggles or negative effects from the use of VR goggles during screening

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