Administration of marijuana to heavy and casual marijuana users.
D000339:Affect / Q000187:drug effects; D001288:Attention / Q000187:drug effects; D002188:Cannabis / Q000494:pharmacology*; D002986:Clinical Trials as Topic; D013759:Dronabinol / Q000494:pharmacology; D004361:Drug Tolerance; D006801:Humans; D009048:Motor Skills / Q000187:drug effects; D010465:Perception / Q000187:drug effects; D010865:Pilot Projects; D010919:Placebos; D011581:Psychological Tests
D010919:Placebos; D013759:Dronabinol