14576 Stepahn Teyssen/Manfred Singer: Alkohol. Das unterscha''tzte Gift. Spektrum 2001/4, 58-67, Spektrum 2001/7, 8. 10045 Ingrid Wickelgren: Marijuana - harder than thought? Science 27 June 1997, 1967-1968. Contrary to the popular view that marijuana is a relatively benign drug, new evidence suggests its effects in the brain resemble those of heroin and cocaine.