It doesn't take much LSD, short for lysergic acid diethylamide, to substantially alter a person's state of consciousness. Compared with many other substances, the amounts are very small, says Dr Volker Auwärter, director of the forensic toxicology laboratory at the University of Freiburg Medical Centre in Germany: "Upwards of 50, 100 micrograms are said to be a psychedelic dose." The European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) calls the hallucinogen "one of the most potent d