At its heart, though, the ruling cements into place the image of the federal government's position on pot as something akin to a large boulder in the middle of a raging stream. It has been 40 years since the DEA concluded that that marijuana "has no currently accepted medical use in treatment in the United States." Since then, 18 states and the District of Columbia -- one third of all such jurisdictions -- have legalized the use of medical marijuana while two states, Colorado and Washington, have legalized the recreational use of marijuana.

And how have the DEA and the Department of Health and Human Services reacted to all this? Unmoved and unmoving. Not yet convinced of what they are seeing with their own eyes, federal regulators insist that marijuana still can't be re-classified so that more Americans can more lawfully use it to ward off their pain or their nausea or whatever other effects of serious illness they contend it helps with. Here's the short version of how these regulators justify their continued inaction. First, from Tuesday's ruling, the background:

A drug is placed in Schedule I if (1) it "has a high potential for abuse," (2) it has "no currently accepted medical use in treatment in the United States," and (3) "[t]here is a lack of accepted safety for use of the drug . . . under medical supervision." (emphasis added). A criterion for Schedule III, IV, and V drugs is the existence of "a currently accepted medical use in treatment in the United States." To assess whether there is a "currently accepted medical use," the DEA looks for five necessary elements: "(1) The drug's chemistry must be known and reproducible; (2) There must be adequate safety studies; (3) There must be adequate and well-controlled studies proving efficacy; (4) The drug must be accepted by qualified experts; and (5) The scientific evidence must be widely available." Unlike Schedule I drugs, federal law permits individuals to obtain Schedule II, III, IV, or V drugs for personal medical use with a valid prescription (citations omitted by me).

The plaintiffs in this case asked the DEA to reclassify marijuana in 2002. The DEA then submitted the request to the DHHS. It took four years for the DHHS to conclude that such a re-classification was unjustified. And then it took the DEA five more years to formally deny the plaintiffs' request for a re-classification of the drug. To offer some perspective on the slow march in play here, during the nine-year span from 2002 to 2011 during which this issue was live before the DEA nine states and the District of Columbia passed medical marijuana laws.

The D.C. circuit now again picks up the trail. Why specifically did the DHHS reject the request to re-classify marijuana? From the ruling:

In its scientific and medical evaluation, DHHS concluded that marijuana lacks a currently accepted medical use in the United States. In reaching this conclusion, DHHS applied the DEA's established five-prong test, which requires a known and reproducible drug chemistry, adequate safety studies, adequate and well-controlled studies demonstrating efficacy, acceptance of the drug by qualified experts, and widely available scientific evidence. DHHS stated that there are approximately known components of the cannabis plant. The components include 66 compounds called cannabinoids, and marijuana is the only plant in which these compounds are known to exist. DHHS stated, however, that marijuana's chemistry was not "known and reproducible" as there had not been "a complete scientific analysis" of its components. In addition, although there was ongoing research, there were no studies of sufficient quality to assess "the efficacy and full safety profile of marijuana for any medical condition." Further, there was "a material conflict of opinion among experts" as to medical safety and efficacy, thereby precluding a finding that qualified experts accepted marijuana as a medicine. Additionally, the raw research data typically were not available in a format that would allow "adequate scientific scrutiny of whether the data demonstrate safety or efficacy" (citations omitted by me).

Why did the DEA "adhere" to the DHHS's recommendation? Again, the federal appeals court shared with the public the agency's rationale:

To establish accepted medical use, the effectiveness of a drug must be established in well-controlled, well designed, well-conducted, and well-documented scientific studies, including studies performed in a large number of patients. To date, such studies have not been performed. The small clinical trial studies with limited patients and short duration are not sufficient to establish medical utility. Studies of longer duration are needed to fully characterize the drug's efficacy and safety profile. Scientific reliability must be established in multiple clinical studies. Furthermore, anecdotal reports and isolated case reports are not adequate evidence to support an accepted medical use of marijuana. The evidence from clinical research and reviews of earlier clinical research does not meet this standard (citations omitted by me).

The D.C. circuit then tried again to explain the difference between how the regulators view "scientific studies" and how the plaintiffs in the case would like them to view "scientific studies":

[A] limited number of Phase I investigations have been conducted as approved by the FDA. Clinical trials, however, generally proceed in three phases. Phase I trials encompass initial testing in human subjects, generally involving 20 to 80 patients. They are designed primarily to assess initial safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary studies of potential therapeutic benefit. Phase II and Phase III studies involve successively larger groups of patients: usually no more than several hundred subjects in Phase II and usually from several hundred to several thousand in Phase III.

These studies are designed primarily to explore (Phase II) and to demonstrate or confirm (Phase III) therapeutic efficacy and benefit in patients. No Phase II or Phase III studies of marijuana have been conducted. Even in 2001, DHHS acknowledged that there is "suggestive evidence that marijuana may have beneficial therapeutic effects in relieving spasticity associated with multiple sclerosis, as an analgesic, as an antiemetic, as an appetite stimulant and as a bronchodilator." But there is still no data from adequate and well-controlled clinical trials that meets the requisite standard to warrant rescheduling.

I suppose there are two ways in which proponents of medical marijuana are likely to react to this ruling -- and to the scientific justification for the federal government's refusal to re-classify the drug. They are likely to try to put political pressure on the DEA and the DHHS from above, that is to say politically. And they are likely to ramp up their efforts on the ground to conduct and conclude the sorts of "scientific studies" which the regulators say they need to see before they'll give medical marijuana clearance to get beyond "Schedule 1."