Archaeologists unearthed traces of cannabis with high levels of THC (the main psychoactive component of cannabis) in wooden bowls dating to 500 BCE in the Jirzankal Cemetery in China, marking the earliest instance of marijuana use found to date. This particular use of marijuana was more likely for a religious rite than medicinal purposes, though religion and medicine were not necessarily kept separate. Such use was described by Greek historian Herodotus: “The Scythians then take the seed of this hemp and, crawling in under the mats, throw it on the red-hot stones, where it smolders and sends forth such fumes that no Greek vapor-bath could surpass it. The Scythians howl in their joy at the vapor-bath.”
The mythological Chinese Emperor Shennong’s pharmacopeia, Treatise on Medicine (which itself has disputed dates–2737 BCE or 1CE and unknown authorship), included marijuana as a treatment for “malaria, constipation, rheumatic pains, ‘absentmindedness’ and ‘female disorders.’”
From China, marijuana was introduced to Iran and Anatolia by the Scythians and then spread to India, Greece, Egypt, and throughout Africa. Evidence suggests Arab physicians used marijuana for pain, inflammation, and epileptic seizures, while in India marijuana was used for fevers, sexually transmitted infections (STIs), headaches, sleep, dysentery, digestion, and appetite inducement. In Rome, Emperor Nero’s private physician, Dioscorides, used the plant to treat pain in ears. Marijuana was similarly used in Africa, as evidenced by the Egyptian Ebers papyrus (circa 1550 BCE), for fever, pain, infected toenails, and uterine cramps. Other Egyptian papyruses include cannabis as treatment for eye infections (perhaps glaucoma), cholera, menstrual ailments, headaches, schistosomiasis, fever, and colorectal cancer.
The Moors brought marijuana to Spain during the 8th-century occupation. The Spanish, in turn, took marijuana to the Americas where it was mainly used as a cash crop for producing hemp fiber. Medical use followed quickly, with Mexicans using the drug for gonorrhea, menstrual ailments, pain, and toothaches.
Robert Burton’s The Anatomy of Melancholy (1621) heralded the arrival of marijuana in medieval Europe by suggesting that cannabis be used to treat depression. Thereafter marijuana was recommended for inflammation (New English Dispensatory, 1764) and coughs, STIs, and incontinence (Edinburgh New Dispensary, 1794).
Medical use of marijuana did not gain much popularity in the United Kingdom until W.B. O’Shaughnessy, an Irish professor at the Medical College of Calcutta, India, tested the indigenous Cannabis indica on animals and children after seeing how Indians used marijuana in medicine. O’Shaughnessy reported in 1839 that cannabis was safe and used marijuana to treat rabies, cholera, delirium from alcohol withdrawal, pain, rheumatism, epilepsy, tetanus, and as a muscle relaxer. He deemed marijuana “an anticonvulsant remedy of the greatest value” and brought the drug with him when he returned to England in 1842.
The Provincial Medical and Surgical Journal (now the British Medical Journal) put medical cannabis on the front page in 1843, prompting popularity and regular use of the drug as a painkiller, with even Queen Victoria reportedly being prescribed marijuana postpartum and for premenstrual syndrome (PMS) by her private physician J.R. Reynolds. A tincture of marijuana, frequently added to tea, was used commonly in Victorian England. The 1894 Indian Hemp Drugs Commission stated marijuana was not harmful if used in moderation and could be particularly helpful in treating malaria.
In 1860, American doctor R.R. M’Meens, crediting W.B. O’Shaughnessy, extolled the virtues of marijuana to treat “tetanus, neuralgia, dysmenorrhea (painful menstruation), convulsions, the pain of rheumatism and childbirth, asthma, postpartum psychosis, gonorrhea, and chronic bronchitis” as well as the drug’s use for sleep-inducement and appetite stimulation. Other American doctors prescribed marijuana for restlessness, anxiety, “senile insomnia,” neuralgia, migraines, depression, gastric ulcers, morphine addiction, and asthma, and as a topical anesthetic.
However, the arrival of marijuana wasn’t lauded by everyone. Mark Stewart, a member of the UK Parliament, complained in 1891 that “the lunatic asylums of India are filled with ganja smokers.” Along with negative associations with mental illness, marijuana was also attacked with racist political commentary. In the United States, the Federal Bureau of Narcotics (FBN) Commissioner Harry Anslinger claimed there were “100,000 total marijuana smokers in the U.S., and most are Negroes, Hispanics, Filipinos and entertainers. Their Satanic music, jazz and swing result from marijuana use. This marijuana causes white women to seek sexual relations with Negroes, entertainers and any others.” Additionally, the agency was concerned that “marihuana leads to pacifism and communist brainwashing.”
By the 1890s, marijuana was falling out of favor among doctors, and U.S. states were working to ban marijuana because of the drug’s association with Mexican immigrants. Massachusetts led the charge, passing a ban on the drug in 1911.
The FBN, which would merge with other departments to form what is now the Drug Enforcement Administration (DEA), worked to pass the Marihuana Tax Act of 1937. While the law only taxed marijuana, it effectively banned the drug as well as industrial hemp. The Marihuana Tax Act survived until 1969 when it was declared unconstitutional. However, President Richard Nixon would reinstate the marijuana ban in 1970 with the Controlled Substances Act, which classified cannabis as a Schedule 1 drug (“drugs with no currently accepted medical use and a high potential for abuse”), beginning Nixon’s “War on Drugs” and effectively ending medical research on the drug.
In the United Kingdom, the Misuse of Drugs Act was passed in 1971, declaring marijuana to have “no known or limited medical use.” The law now classifies marijuana as a Class B drug, which are considered less dangerous than Class A drugs including cocaine, ecstasy, and crystal meth. Class B drugs include amphetamines, barbiturates, and ketamine, along with marijuana. The possession of any Class B drug carries a penalty of up to 5 years in prison.
While the American federal war on drugs would continue, US states began legalizing medical marijuana in the 1990s. California was the first to legalize cannabis for medical use in 1996, quickly followed by Alaska, Oregon, and Washington state in 1998, and Maine in 1999. By Dec. 2022, 37 states and DC had legalized medical marijuana, leaving only 13 states where medical marijuana is illegal: Georgia, Idaho, Indiana, Iowa, Kansas, Kentucky, Nebraska, North Carolina, South Carolina, Tennessee, Texas, Wisconsin, and Wyoming.
While states were legalizing medical marijuana, some of the earliest adopting states also began legalizing recreational, or adult-use, marijuana. Colorado and Washington legalized this in 2012–19 other states and DC had done so by December 2022. Only states with legal medical marijuana have thus far legalized adult-use marijuana.
An Apr. 2021 Pew Research Center poll found that 91% of Americans believed marijuana should be legal for medical use (60% for medical and recreational legalization; and 31% for only medical legalization). Only 8% believed marijuana should not be legal for any reason, and 1% did not answer the question. Support for marijuana legalization has steadily increased over the years.
For more on the history of medical marijuana, see ProCon’s Historical Timeline: History of Marijuana as Medicine – 2900 BC to Present.