This study involves evaluating the occupancy of ATI-9242 at steady state at three different dose levels on D2 receptors in the brain using [18F]Fallypride PET in up to three cohorts of subjects. The first dose evaluated will be 0.5 mg/kg administered as an IV bolus injection. The second dose that will be evaluated will be 1.0 mg/kg as an IV bolus injection. The safety and occupancy after each dose level will be evaluated prior to moving to the next dose. On two separate days, subjects will undergo [18F]Fallypride PET imaging sessions. The plasma concentration of ATI-9242 will be obtained prior to and during the course of the imaging session to allow determination of the relationship between plasma concentration of ATI-9242 with in vivo D2 occupancy.