It is unclear when cannabis first became known for its psychoactive properties. The oldest archeological evidence for the burning of cannabis was found in Romanian kurgans dated 3,500 BC, and scholars suggest that the drug was first used in ritual ceremonies by Proto-Indo-European tribes living in the Pontic-Caspian steppe during the Chalcolithic period, a custom they eventually spread throughout western Eurasia during the Indo-European migrations. Some research suggests that the ancient Indo-Iranian drug soma, mentioned in the Vedas, sometimes contained cannabis. This is based on the discovery of a basin containing cannabis in a shrine of the second millennium BC in Turkmenistan.Cannabis was known to the ancient Assyrians, who discovered its psychoactive properties through the Iranians. Using it in some religious ceremonies, they called it qunubu (meaning "way to produce smoke"), a probable origin of the modern word "cannabis". The Iranians also introduced cannabis to the Scythians, Thracians and Dacians, whose shamans (the kapnobatai – "those who walk on smoke/clouds") burned cannabis infructescences to induce trance. The plant was used in China before 2800 BC, and found therapeutic use in India by 1000 BC, where it was used in food and drink, including bhang. Cannabis has an ancient history of ritual use and has been used by religions around the world. The earliest evidence of cannabis smoking has been found in the 2,500-year-old tombs of Jirzankal Cemetery in the Pamir Mountains in Western China, where cannabis residue were found in burners with charred pebbles possibly used during funeral rituals.
There is limited evidence suggesting cannabis can be used to reduce nausea and vomiting during chemotherapy, to improve appetite in people with HIV/AIDS, or to treat chronic pain and muscle spasms. Its use for other medical applications is insufficient for drawing conclusions about safety or efficacy. There is evidence supporting the use of cannabis or its derivatives in the treatment of chemotherapy-induced nausea and vomiting, neuropathic pain, and multiple sclerosis. Lower levels of evidence support its use for AIDS wasting syndrome, epilepsy, rheumatoid arthritis, and glaucoma.So far, the medical use of cannabis is legal only in a limited number of territories, including Canada, Belgium, Australia, the Netherlands, New Zealand, Spain, and many U.S. states. This usage generally requires a prescription, and distribution is usually done within a framework defined by local laws. Recreational
According to DEA Chief Administrative Law Judge, Francis Young, "cannabis is one of the safest therapeutically active substances known to man." Being under the effects of cannabis is usually referred to as being "high" or "stoned." Cannabis consumption has both psychoactive and physiological effects. The "stoned" experience can vary widely, based (among other things) on the users prior experience with cannabis, and the type of cannabis consumed. : p647  When smoking cannabis, a euphoriant effect can occur within minutes of smoking.