Many drugs are used for their mood and perception change effects, including those with accepted uses in medicine and psychiatry. There is archaeological evidence for the use of psychoactive substances dating back at least 10 000 years, as well as historical data for cultural purposes in the last 5000 years. Some psychoactives, particularly hallucinogens, have been used for religious purposes since prehistoric times. Examples of traditional entheogens include: kykeon, ambrosia, iboga, soma, peyote, ayahuasca. Other traditional entheogens include cannabis, ethanol, ergine, psilocybe mushrooms, opium. Although entheogens are taboo and most of them are officially banned in Christian and Islamic societies, their ubiquity and importance in terms of different spiritual traditions of other cultures is unquestioned.