The history of cannabis and its usage by humans dates back to at least the third millennium BCE in written history, and possibly far further back by archaeological evidence. For millennia, the plant has been valued for its use for fiber and rope, as food and medicine, and for its psychoactive properties for religious and recreational use.
Cannabis is indigenous to Central and South Asia. Hemp is possibly one of the earliest plants to be cultivated. Cannabis has been cultivated in Japan since the pre-Neolithic period, for its fibres and as a food source, and possibly as a psychoactive material. An archeological site in the Oki Islands near Japan contained cannabis achenes from about 8000 BC, probably signifying use of the plant.Hemp use archaeologically dates back to the Neolithic Age in China, with hemp fiber imprints found on Yangshao culture pottery dating from the 5th millennium BC. The Chinese later used hemp to make clothes, shoes, ropes, and an early form of paper. Cannabis was an important crop in ancient Korea, with samples of hempen fabric discovered dating back as early as 3000 BCE. The earliest written reference to cannabis dates back to 2727 BC, from the Chinese emperor Shennong.
Cannabis was also known to the ancient Assyrians, who discovered its psychoactive properties through the Aryans. Using it in some religious ceremonies, they called it qunubu (meaning “way to produce smoke”), a probable origin of the modern word “cannabis”. The Aryans also introduced cannabis to the Scythians, Thracians and Dacians, whose shamans (the kapnobatai—”those who walk on smoke/clouds”) burned cannabis flowers to induce trance. The classical Greek historian Herodotus (ca. 480 BC) reported that the inhabitants of Scythia would often inhale the vapors of hemp-seed smoke, both as ritual and for their own pleasurable recreation.
Medical cannabis has several potential beneficial effects. Evidence is moderate that it helps in chronic pain and muscle spasms. Low quality evidence suggests its use for reducing nausea during chemotherapy, , improving sleep, and improving tics in Tourette syndrome. When usual treatments are ineffective, cannabinoids have also been recommended for anorexia, arthritis, migraine, and glaucoma.
Cannabis has psychoactive and physiological effects when consumed. The immediate desired effects from consuming cannabis include relaxation and euphoria (the “high” or “stoned” feeling).
Cannabis has been used in an entheogenic context – a chemical substance used in a religious, shamanic, or spiritual context – in India and Nepal since the Vedic period dating back to approximately 1500 BCE, but perhaps as far back as 2000 BCE. In modern culture the spiritual use of cannabis has been spread by the disciples of the Rastafari movement who use cannabis as a sacrament and as an aid to meditation. The earliest known reports regarding the sacred status of cannabis in India and Nepal come from the Atharva Veda estimated to have been written sometime around 2000–1400 BCE.