IMPORTANCE Vaporization is an increasingly popular method for cannabis administration,and policy changes have increased adult access to cannabis drastically.Controlled examinations of cannabis vaporization among adults with infrequent current cannabis use patterns(>30 day ssince lastuse)are needed. OBJECTIVE: To evaluate the acute dose effects of smoked and vaporized cannabis using controlled administration methods. DESIGN,SETTING,AND PARTICIPANTS This within-participant,double-blind,crossover study was conducted from June 2016 to January 2017 at the Behavioral Pharmacology Research Unit, Johns Hopkins University School of Medicine, and included 17 healthy adults. Six smoked and vaporized outpatient experimental sessions (1-week wash out between sessions)were completed in clusters (order counterbalanced across participants);dose order was randomized within...