Ms. F., an 18-year-old female high school student was admitted to the internal medicine service of a university-affiliated teaching hospital for investigation of confusion and an altered level of consciousness. The previous night, she had smoked marijuana, drunk a small amount of tea containing psilocybin ("magic mushrooms"), and taken one tablet of ecstasy at an all-night party. The following day, Ms. F. returned to her parents' home in a confused and disoriented state. She was taken to the emergency department, where she displayed a fluctuating level of consciousness; disorientation to name, place, and time; marked loosening of associations; and bizarre, agitated, and sexually inappropriate behavior... A diagnosis of hallucinogenic (and possibly cannabis-induced) delirium was made....