Humans have cultivated and consumed the flowering tops of the female cannabis plant, colloquially known as marijuana, since virtually the beginning of recorded history. Cannabis-based textiles dating to 7,000 B.C.E have been recovered in northern China, and the plant's use as a medicinal and mood altering agent date back nearly as far. In 2008, archeologists in Central Asia discovered over two-pounds of cannabis in the 2,700-year-old grave of an ancient shaman. After scientists conducted extensive testing on the material's potency, they affirmed, "[T]he most probable conclusion ... is that [ancient] culture[s] cultivated cannabis for pharmaceutical, psychoactive, and divinatory purposes."
Modern cultures continue to indulge in the consumption of cannabis for these same purposes, despite a present-day, virtual worldwide ban on the plant's cultivation and use. In the United States, federal prohibitions outlawing cannabis' recreational, industrial, and therapeutic use were first imposed by Congress under the Marihuana Tax Act of 1937 and then later reaffirmed by federal lawmakers' decision to classify marijuana -- as well as all of the plant's organic compounds (known as cannabinoids) -- as a Schedule I substance under the Controlled Substances Act of 1970.
This classification, which asserts by statute that cannabis is equally as dangerous to the public as is heroin, defines cannabis and its dozens of distinct cannabinoids as possessing 'a high potential for abuse, ... no currently accepted medical use, ... [and] a lack of accepted safety for the use of the drug ... under medical supervision.'
(By contrast, cocaine and methamphetamine -- which remain illicit for recreational use but may be consumed under a doctor's supervision -- are classified as Schedule II drugs; examples of Schedule III and IV substances include anabolic steroids and Valium respectively, while codeine-containing analgesics are defined by a law as Schedule V drugs, the federal government's most lenient classification.)
In July 2011, the Obama Administration rebuffed an administrative inquiry seeking to reassess cannabis' Schedule I status, and federal lawmakers continue to cite the drug's dubious categorization as the primary rationale for the government's ongoing criminalization of the plant and those who use it.
For example, in February 2010 investigators at the University of California Center for Medicinal Cannabis Research publicly announced the findings of a series of randomized, placebo-controlled clinical trials on the medical utility of inhaled cannabis. The studies, which utilized the so-called 'gold standard' FDA clinical trial design, concluded that marijuana ought to be a "first line treatment" for patients with neuropathy and other serious illnesses.