Medical Examiner

All Smoke

The FDA’s statement on medical marijuana isn’t about science.

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Medicinal marijuana

Last week, the Food and Drug Administration reported that it had definitively established that marijuana has no medical use or value. Definitively? Established? I don’t think so. 

The FDA’s announcement begins by acknowledging the claim that smoked marijuana may be beneficial for some conditions. Then the agency points out that among drugs with a potential for abuse, marijuana is lumped in with the most dangerous drugs, the ones that have no potential medical benefits and the highest likelihood of misuse. The FDA next affirms that a collection of federal agencies have together concluded that marijuana is both dangerous and medically valueless, based on scientific studies in humans and animals. The announcement—actually, it’s an “inter-agency advisory”—concludes by asserting, with a boldness that might belie a certain uneasiness, that it is the FDA’s job to approve drugs. Take that, state legislatures and voters.

The FDA’s statement implies that the agency reached its conclusion about marijuana after conducting a new serious analysis of the existing scientific literature on the drug. But of course no such analysis was reported in the medical literature and, in fact, no identifiable official at the FDA took responsibility for last week’s advisory. It was just put out there as a statement of fact. 

But it’s not. In 1999, the Institute of Medicine, the medical arm of the National Academy of Sciences (an organization chartered by Congress to provide independent, nonpartisan scientific and technological advice) examined this same question in considerable depth and published a 288-page report of its findings. Put together by 11 distinguished scientists and physicians, the IOM report examined the known and potential harms of marijuana use and the known and potential medical benefits. The report is broad in its vision and thoughtful and cautious in its interpretations and recommendations. Its authors acknowledged that the medical uses of marijuana entail some risk of harm—for instance, it’s pretty clear that inhaling marijuana smoke can’t be good for the lungs, and who knows if there are significant psychological side effects for some users. But the authors concluded that these risks were not terribly high. They also found that other putative risks often attached to this drug—the potential for addiction, for instance, or for marijuana serving as a “gateway” to further drug abuse—were much overstated. The report urged further study to determine the real level of risk.

In examining the potential medical benefits of medical marijuana, the IOM report was equally cautious. It described relief from nausea associated with cancer chemotherapy, appetite stimulation for cancer and HIV patients, and treatment of muscle spasticity for patients with multiple sclerosis or spinal cord injury. Though these benefits seem real, the authors of the IOM report point out that we really don’t know yet if they are significant or valuable enough to warrant the use of medical marijuana. Again, the report urged further study to determine the real level of benefit.

However, in the seven years since the IOM report was issued, virtually no research on potential risks and benefits has been done, because the government has blocked such studies. So, we know neither more nor less about medical marijuana than we did seven years ago, whatever the FDA says. Why would the agency inaccurately claim that the science is settled when it isn’t? I hardly need to say it: This isn’t a medical or scientific conclusion. It’s a political one.

This is certainly not the first time that politics has trumped science at the FDA. Another recent example: the agency’s decision to block over-the-counter availability for emergency contraceptives in the face of overwhelming evidence that the treatment is safe and effective, and support for over-the-counter availability by the FDA’s own advisory committee. From my standpoint as a doctor, the question is this: What do you do when federal agencies become so politicized that their recommendations can’t necessarily be trusted? Do you have to treat other things they say as suspect? I depend on good advice and honest information from government agencies in the daily conduct of my work. I need to know what epidemic illnesses are circulating in my neighborhood even if that information might put a government agency in a bad light. I need to be able to trust government-sponsored research (especially because, goodness knows, I have learned not to trust manufacturer-sponsored research). I need to know that the advice I glean from government-sponsored agency Web sites will lead to the best care for my patients.

Marijuana as a medicine—whatever its risk and benefits are eventually determined to be—may turn out to be much less important than the question of whether we can count on agencies like the FDA to be honest in their dealings.