At the center of the country's marijuana legalization debate is the US drug scheduling system, which the federal government has used for decades to regulate what it defines as a controlled substance.

When the New York Times Editorial Board on July 26 endorsed federal legalization and initiated another round of the national debate, it essentially called on the federal government to undo its strict classification of marijuana and leave it up to the states to regulate the production, sales, and possession of pot. The classification is one of the major reasons states face legal hurdles and federal obstruction when they try to legalize marijuana for recreational and medical purposes.

But short of very unlikely congressional action, changing or removing a drug's schedule is very complicated.

How does the US classify illicit drugs like marijuana?

Under the Controlled Substances Act, the federal government — which has largely relegated the regulation of drugs to the Drug Enforcement Administration (DEA) — puts each drug into a classification, known as a schedule, based on its medical value and potential for abuse.

To initiate a schedule, the DEA first asks if a drug can be abused. If the answer is yes, then it's put on a schedule. If no, the drug is left out. After that, the drug's medical value and relative potential for abuse are evaluated to decide where on the scale it lands.

Congress did not clearly define abuse under the Controlled Substances Act

The two big issues, then, are a drug's potential for abuse and its medical value. Congress did not clearly define abuse under the Controlled Substances Act. But for federal agencies responsible for classifying drugs, abuse is when individuals take a substance recreationally and develop personal health hazards or pose other risks to society as a whole. To find medical value, a drug must have large-scale clinical trials to back it up — similar to what the Food and Drug Administration would expect from any other drug entering the market.



There are five numbered schedules, but the numbers don't necessarily mean that Schedule 1 substances are more dangerous than Schedule 2 drugs. Instead, the scheduling system is essentially two parts: Schedule 1 drugs have no medical value and high potential for abuse, while Schedule 2 through 5 substances all have some medical value but differ in ranking depending on their potential for abuse (from high to low).

Some examples of the drugs that are on each schedule:

Schedule 1: marijuana, heroin, LSD, ecstasy, and magic mushrooms



Schedule 2: cocaine, meth, oxycodone, Adderall, Ritalin, and Vicodin



Schedule 3: Tylenol with codeine, ketamine, anabolic steroids, and testosterone



Schedule 4: Xanax, Soma, Darvocet, Valium, and Ambien



Schedule 5: Robitussin AC, Lomotil, Motofen, Lyrica, and Parepectolin

In general, Schedule 1 and 2 drugs have the most regulatory restrictions on research, supply, and access, and Schedule 5 drugs have the least.

Does the federal government really consider marijuana more dangerous than cocaine?

The DEA says Schedule 1 substances, such as heroin and marijuana, "are considered the most dangerous class of drugs with a high potential for abuse and potentially severe psychological and/or physical dependence." Schedule 2 substances, such as cocaine and meth, are defined as "drugs with a high potential for abuse, less abuse potential than Schedule [1] drugs, with use potentially leading to severe psychological or physical dependence."

That doesn't necessarily mean the federal government views marijuana and heroin as equally dangerous drugs, or that it considers marijuana to be more dangerous than meth or cocaine. The big distinction between Schedule 1 and 2 substances is whether the federal government thinks a drug has medical value. The DEA says Schedule 2 substances have some medical value and Schedule 1 substances do not, so the latter receive more regulatory scrutiny even though they may not be more dangerous.

The war on drugs was initiated when much of the nation was in hysterics about what drugs would do to the moral fabric of the country

It may be helpful to think of the scheduling system as made up of two distinct groups: nonmedical and medical. The nonmedical group comprises the Schedule 1 drugs, which are considered to have no medical value and high potential for abuse. The medical group comprises the Schedule 2 to 5 drugs, which have some medical value and are numerically ranked based on abuse potential (from high to low).

There are some cultural considerations to the scheduling system, as well. The war on drugs was initiated at a time when much of the nation was in hysterics about what drugs like marijuana and LSD would do to the moral fabric of the country. Marijuana was seen as dangerous not necessarily because of its direct health effects, but because of the perception — partially rooted in racial prejudices — that pot makes people immoral, lazy, crazy, and even violent. This perception persists among many supporters of the war on drugs to this day, and it's still reflected in America's drug scheduling.

Beyond the scheduling system, the federal government imposes criminal trafficking penalties for drugs that don't always align with their scheduling. For instance, marijuana trafficking is generally punished less severely than cocaine. And state governments can set up their own criminal penalties and schedules for drugs as well.

Why does a drug's schedule matter?

A drug's schedule sets the groundwork for the federal regulation of a controlled substance.

Schedule 1 and 2 drugs face the strictest regulations. Schedule 1 drugs are effectively illegal for anything outside of research, and Schedule 2 drugs can be used for limited medical purposes with the DEA's approval.

The DEA even sets strict limits on the production of Schedule 1 and 2 drugs, although the limits vary from drug to drug. Only one place in the US — a University of Mississippi farm — is allowed to grow marijuana under federal regulations, and the pot is limited to research purposes. By comparison, several private companies produce oxycodone, a Schedule 2 substance, and use the drug for prescription painkillers.

A drug's schedule can interfere with state laws. Marijuana's Schedule 1 status is one reason banks are reluctant to open accounts for pot shops and growers in Colorado and Washington, even though the businesses are legal under state law.

A drug's schedule can interfere with state laws

Federal tax law also prohibits businesses from deducting many expenses related to the trafficking of Schedule 1 and 2 drugs, which can cause state-legal marijuana businesses' effective income tax rates to soar as high as 90 percent.

The DEA sometimes uses marijuana's classification to pressure physicians, hospitals, and pharmacies into not working with medical marijuana operations that are compliant with state law. If these medical providers don't comply, the DEA threatens to take back licensing that lets doctors prescribe drugs, such as prescription painkillers with oxycodone, that contain scheduled substances.

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 US attorney general 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:

The DEA, US Department of Health and Human Services, or a public petition initiate a review. The DEA requests HHS to review the medical and scientific evidence regarding a drug's schedule. 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. HHS recommends a schedule based on the scientific evidence. 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 in 2014 announced it had 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," former DEA head Michele Leonhart said in a 2014 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.

One 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 major recreational drugs not on the scheduling system — alcohol and tobacco — required a specific exemption in the Controlled Substances Act. Mark Kleiman, a drug policy expert, 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 deadly.

Why is marijuana still Schedule 1?

When marijuana's classification comes under review, its Schedule 1 status is consistently maintained due to insufficient scientific evidence of its medical value.

Specifically, the scientific evidence available for marijuana doesn't pass the threshold required by federal agencies to acknowledge a drug's potential as medicine. HHS's 2006 review of marijuana's schedule found several problems: No studies proved the drug's medical efficacy in controlled, large-scale clinical environments, no studies established adequate safety protocols for marijuana, and marijuana's full chemical structure has never been characterized and analyzed.

But one reason there isn't enough scientific evidence to change marijuana's Schedule 1 status might be, in fact, the drug's Schedule 1 status. The DEA restricts how much marijuana can go to research. To obtain legal marijuana supplies for studies, researchers must get their studies approved by HHS, the FDA, and the DEA. (This process didn't even exist until the late 1990s. Before then, it was nearly impossible to obtain marijuana for medical research.)

Changing marijuana's schedule is a bit of a catch-22



Changing marijuana's schedule, in other words, is a bit of a catch-22. There needs to be a certain level of scientific research that proves marijuana has medical value, but the federal government's restrictions make it difficult to conduct that research.

The insufficient evidence even includes a federally commissioned study. In the 1990s, the federal government tasked the prestigious Institute of Medicine (IOM) to study pot's medical use. IOM's in-depth report, released in 1999, concluded marijuana is "moderately well suited for particular conditions, such as chemotherapy-induced nausea and vomiting and AIDS wasting."

The report also found that the drug is not particularly addictive and not a gateway drug. The only downside uncovered by researchers was that marijuana is usually smoked — researchers feared that could cause health problems in the long term, but that issue can now be overcome through vaporization pens and edibles.

More studies came out in support of medical marijuana after IOM's review, but the IOM study gets a lot of attention since it was commissioned by the federal government.

HHS's 2006 review argued the IOM study merely supported further research into marijuana's medical potential, since the study's findings weren't based on large-scale clinical trials. The review cites the IOM study: "If there is any future for marijuana as a medicine, it lies in its isolated components, the cannabinoids and their synthetic derivatives. Isolated cannabinoids will provide more reliable effects than crude plant mixtures. Therefore, the purpose of clinical trials of smoked marijuana would not be to develop marijuana as a licensed drug but rather to serve as a first step toward the development of nonsmoked rapid-onset cannabinoid delivery systems."

Some of the researchers involved in the IOM study take issue with the federal government's interpretation. John Benson, one of the authors of the IOM report, previously told the New York Times that the federal government's 2006 review was wrong. The federal government "loves to ignore our report," Benson said. "They would rather it never happened."

The government "loves to ignore our report. They would rather it never happened."

While a reclassification would be a symbolic win for legalization advocates, Kleiman says it wouldn't have much practical effect. Schedule 2 substances typically require a prescription to be distributed, and neither recreational nor medical marijuana dispensaries work through prescriptions.

Kevin Sabet, co-founder of the anti-legalization Smart Approaches to Marijuana and a supporter of marijuana's Schedule 1 status, told me in August 2014 that federal agencies can and should allow more research into marijuana and its various cannabinoids, such as CBD and THC, without reducing marijuana's schedule.

"We have advocated that the FDA start a compassionate research program now for components or different parts of marijuana, including the whole plant," Sabet said in August.

Still, moving marijuana down to a Schedule 3 substance could help in a few significant ways. It could allow marijuana businesses to deduct expenses from their taxes. It would also loosen restrictions on producing and selling the plant for medical and research purposes. But, at least for now, such a drastic down-scheduling is not very likely.

Is there an alternative to the scheduling system?

Kleiman has proposed moving to a scheduling system that looks only at a drug's potential for abuse without considering whether it has medical value. The regime would control all intoxicating drugs, including alcohol, to try to prevent problematic drug use, based on the scientific definition of drug abuse disorders. Whether a drug has medical value would be addressed by a different set of policies focused on medical drug production and health care.

"Whether something is medication is a separate set of issues," Kleiman said. His ideal system "would classify drugs by dangerousness, with a penalties for dealing ramping up with more dangerous drugs."

"The current prohibition system has generated many bad side effects"

One of the problems with the current scheduling system, Kleiman argued, is it tries to lump drugs with completely different effects and risks into a few categories. "There are lots of different drugs in the world, and we have to figure out what to do with each of them," Kleiman said. "Some categorization is helpful, but it's not as if the drugs neatly break down."

Kleiman, who supports decriminalizing illicit drug use, said an ideal replacement to the current scheduling system would also come with less stringent criminal penalties.

"The current prohibition system has generated many bad side effects," Kleiman said. "We should try to develop new policies that duplicate the success of preventing the development of more drugs that are as big a problem as alcohol, but with fewer of the costs."

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