Federal health authorities have concluded that marijuana "has no accepted medical use." But roughly half of US states have moved to sanction its use for medicinal, or even recreational, purposes.
The US Drug Enforcement Administration (DEA) on Thursday announced that it would not ease the classification of marijuana as a dangerous drug despite growing popular support for legalization across the country.
The DEA conducted a lengthy review of the plant, consulting the Health and Human Services Department (HHS) to determine its medicinal properties.
"HHS concluded that marijuana has a high potential for abuse, has no accepted medical use in the United States and lacks an acceptable level of safety for use even under medical supervision," the DEA said in a letter to petitioners.
Marijuana will remain a "Schedule I" drug, on par with heroin, instead of being downgraded to "Schedule II," which includes narcotics such as cocaine, opium and morphine.
The agency added that it would allow more research into the plant's medical benefits, which will likely lead to more research institutions given authorization to grow marijuana.
As of July, only researchers at the University of Mississippi are allowed to grow the plant under a contract with the National Institute of Drug Abuse.
At least 25 states in the US have permitted the use of some forms of marijuana for medicinal use, although others, including Washington and Colorado, have sanctioned its recreational use for adults.
The DEA's decision was a response to a petition submitted by former state governors of Washington and Rhode Island in 2011.
ls/msh (AP, Reuters)