Developing a Mobile Method to Measure THC-induced Impairment

A Mobile Prototype for a Field Sobriety Test for Cannabis

Marijuana use, for both recreational and therapeutic purposes, is becoming increasingly common as states remove restrictions on use. The increased use raises new concern about the safety of this drug, including its ability to impair basic cognitive and psychomotor tasks, and whether the users are aware of their impairment. We propose to design a simple performance test that users can use in the field, using a cell phone, to assess their level of impairment relative to their own drug-free state. In this preliminary study, we will compare participants' simple task performance after a known dose of delta-9-tetrahydrocannabinol (THC), or placebo, administered under double-blind conditions. In our app the participants will be asked to gauge their own perceived level of impairment (as determined by self-ratings and judgments of impairment) as well as their actual impairment (as gauged by the app), providing important feedback and training about their ability to detect impairment.

Inclusion Criteria:

1. 18-35 years old, males and females (N=44; 36 completers; 18 men, 18 women)

2. BMI 19-26

3. High school education, fluent in English

4. Experienced non-daily marijuana users

   Exclusion Criteria:

5. Current drug/alcohol abuse or dependence

6. Past year drug/alcohol dependence

7. Diagnosis with drug treatment for psychosis/bipolar/schizophrenia

8. Past year major depression

9. Panic/anxiety attacks in past 2 months

10. Post Traumatic Stress Disorder

11. Attention Deficit Hyperactivity Disorder

12. Cardiovascular illness, high blood pressure, abnormal EKG

13. Current medications

14. Pregnant or planning to become pregnant