<prompt> Which of the following is the most common cause of emergency depament visit related to LSD and its related substances?Bad tripFlashbacksSynaesthesiaPapillary dilatation  <response>: The most frequent acute medical emergency associated with LSD use is a panic episode the bad trip, which may persist up to 24 h.A trip is a period of intoxication from a hallucinogenic drug, such as lysergic acid LSD or magic mushrooms psilocybin. It is called a trip because perceptions of the world change so dramatically, it can feel as if a trip to a strange, new land is taken. Unpleasant experience of hallucinogen intoxication is known as a bad trip.Harrison 19e pg: Cocaine and Other Commonly Abused Drugs 