The DEA will still treat weed the same as heroin

Marijuana will remain illegal for any purpose under federal law in the United States, even though it's legal for medical and recreational use in several states with more potentially on the way.

The Drug Enforcement Agency announced on Thursday that weed will continue to be classified as Schedule 1 under the Controlled Substances Act, alongside substances including heroin and GHB.

"There is no evidence that there is a consensus among qualified experts that marijuana is safe and effective for use in treating a specific, recognized disorder," the DEA stated in a highly anticipated report on the decision.

The DEA also stated there is "high potential" for marijuana abuse that can lead to "severe psychological or physical dependence." The report noted that 22 percent of the 19 million marijuana users in 2012 were dependent on the substance according to diagnostic criteria.

As such, the report states that "the known risks of marijuana use have not been shown to be outweighed by specific benefits in well-controlled clinical trials that scientifically evaluate safety and efficacy."

Yet the report also claimed that marijuana is not a gateway drug, stating that "little evidence supports the hypothesis that initiation of marijuana use leads to an abuse disorder with other illicit substances."

DEA chief Chuck Rosenberg told NPR on Wednesday that "this decision isn't based on danger. This decision is based on whether marijuana, as determined by the FDA, is a safe and effective medicine," he said, "and it's not."

The chairman of lobbying group Marijuana Majority, Tom Angell, reacted to the announcement by noting, "President Obama always said he would let science — and not ideology — dictate policy, but in this case his administration is upholding a failed drug war approach instead of looking at real, existing evidence that marijuana has medical value."

The DEA announcement was released in response to a December 2009 petition from Bryan Krumm, a medical marijuana activist in New Mexico.

Marijuana is currently legal for medical and recreational use in four states, and for medical use in 20 others. The upcoming federal election will see five states vote on legalization, with three others voting on matters related to medical marijuana.

In Canada, medical marijuana is legal, and Liberal Prime Minister Justin Trudeau has promised to legalize it for recreational use next year.

Watch the VICE News documentary, Inside America's Billion-Dollar Weed Business: The Grass is Greener

Follow Davide Mastracci on Twitter: @DavideMastracci