Developing a Mobile Method to Measure THC-induced Impairment

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.