LSD is short for Lysergic Acid Diethylamide, a hallucinogenic drug derived from a fungus. It causes powerful distortions in a user's perception of reality and produces vivid hallucinations which can be highly enjoyable or utterly terrifying (generally referred to as "good trips" and "bad trips"). Hallucinations ("trips") start anywhere from twenty minutes to an hour after LSD is taken and can last up to 24 hours. There is no way to stop them and even one dose of LSD can sometimes cause flashbacks to the trip at random intervals, sometimes years after the initial dose. Psychological addiction is the main problem as LSD is not actually physically addictive at all. LSD is most often taken by swallowing small squares of paper, liquid or pellets. Common slang terms include acid, cheer, dots, drop, L, lightening flash, tab and trips. Most side effects both short and long term are psychological and can include panic attacks, mania, depression, nervous breakdowns and triggering of other mental health problems like schizophrenia.