What does it take to reschedule a drug?

Congress could pass a law that changes or restricts a drug's schedule. But Congress mostly leaves scheduling to federal agencies like the DEA. One exception: Congress previously passed the Hillory J. Farias and Samantha Reid Date-Rape Prevention Act of 2000 and added gamma hydroxybutyric acid, a date rape drug, to the scheduling system.

The White House can also initiate a review process that would look at the available evidence and potentially change a drug's schedule. The review includes several steps:

1. The DEA, US Department of Health and Human Services, or a public petition initiate a review.
   
2. The DEA requests HHS to review the medical and scientific evidence regarding a drug's schedule.
   
3. HHS, through the FDA, evaluates the drug and its schedule through an analysis based on eight factors. Among the factors: a drug's potential for abuse, the scientific evidence for a drug's pharmacological effects, and the scientific evidence for a drug's medical use.
   
4. HHS recommends a schedule based on the scientific evidence.
   
5. The DEA conducts its own review, with the HHS's determination in mind, and sets the final schedule.

Although very rigorous, this process has been successfully carried out in the past. For example, the DEA on August 21 announced it rescheduled hydrocodone combination products, or opioid-based prescription painkillers, from schedule 3 to schedule 2. "Almost 7 million Americans abuse controlled-substance prescription medications, including opioid painkillers, resulting in more deaths from prescription drug overdoses than auto accidents," DEA Administrator Michele Leonhart said in a statement. "Today's action recognizes that these products are some of the most addictive and potentially dangerous prescription medications available."

Can a drug be unscheduled?

It's possible, but it's much more difficult than simply rescheduling a drug.

The big hurdle is international treaties. The US is party to international agreements that effectively require some drugs, including marijuana, to remain within the scheduling system.

Proving that a drug has no potential for abuse is also very difficult, if not impossible. An American Scientist analysis, for instance, found even relatively safe marijuana has some potential for dependence; it's less addictive than heroin, meth, cocaine, nicotine, and alcohol, but more addictive than hallucinogens such as LSD, which doesn't cause much, if any, dependence.

The two drugs not on the scheduling system -- alcohol and tobacco -- required a specific exemption in the Controlled Substances Act. Mark Kleiman, a drug policy expert at UCLA, argues both would be marked schedule 1 if they were evaluated today, since they're highly abused, addictive, detrimental to one's health and society, and even deadly.