Megan Johnson

Currently, marijuana is categorized as a controlled substance, yet 14 states and the District of Columbia allow patients to use it for medical purposes

Currently, marijuana is categorized as a controlled substance, yet 14 states and the District of Columbia allow patients to use it for medical purposes

Multiple sclerosis patients can get prescription pot to ease their painful muscle spasms -- if they live in Great Britain, where regulators recently approved a mouth spray made from cannabis, or marijuana. GW Pharmaceuticals, which developed Sativex and is preparing for advanced clinical trials to test its ability to relieve pain for cancer patients, wants to bring it to the United States.

Don't expect the company will have it easy. As far as the federal government is concerned, marijuana has no place in medicine. The Drug Enforcement Administration considers marijuana -- like heroin and LSD -- a schedule I controlled substance. Schedule I drugs are likely candidates for abuse, with no recognized therapeutic benefits. (Cocaine is a schedule II. Cough syrup is a V.)

Yet the medical use of marijuana by Americans is spreading. Fourteen states and the District of Columbia allow patients to use marijuana -- and in some states to grow it -- for medical purposes. Shops legally sell medical pot in California, Colorado, and New Mexico. But federal prosecutors continue to target growers, distributors, and users even in states where medical marijuana is legal.

The legal quagmire has hampered research into marijuana's potential medical benefits. Small studies by the Center for Medicinal Cannabis Research at the University of California, San Diego, demonstrate the pain-relieving ability of smoked marijuana in HIV and multiple sclerosis patients. Thousands of laboratory studies hint at a far greater range of medicinal properties, such as treating Alzheimer's disease, where it may inhibit an enzyme that leads to memory-robbing plaque formation in the brain, and fighting off MRSA infections, since certain compounds in cannabis have been shown to work against the superbug.

But moving beyond lab rats has been tough. Only a handful of double-blind, placebo-controlled clinical studies -- the gold standard of medical research -- have been done. Those favoring human research say it demands uncommon patience and persistence.

Researchers must be cleared by the Drug Enforcement Administration, the proposed study has to pass muster with the U.S. Food and Drug Administration, and then the U.S. Public Health Service conducts its own review of the study's scientific merit and design. The entire process can take years, according to Paul Armentano, deputy director of the National Organization for the Reform of Marijuana Laws, an advocacy group.

Americans can take synthesized THC, the main psychoactive compound in marijuana, as Marinol, a capsule made by Unimed Pharmaceuticals. Margaret Haney, a professor of clinical neurobiology at Columbia University in New York, has studied HIV patients whose appetites were enhanced when they smoked marijuana. Her findings suggest that either smoking pot or taking Marinol stimulates appetite. But there are downsides to both.

A dose of Marinol may take three hours to kick in, while smoked marijuana's effects are almost immediate, she says. Smoking the plant, however, may harm the respiratory system and, especially in young heavy users, the brain. Haney, whose research focuses on marijuana dependence, thinks cannabis could have a place in medicine.

"There are clear medical potentials with this plant," she says. "I am not anti-marijuana, I'm not pro-marijuana. I want to understand it." Haney expresses frustration at what she considers wrongheaded efforts by states to legalize medical marijuana. There is too much, she says, that scientists do not know.

The American Medical Association asked the government last November to review marijuana's schedule I status. Downgrading cannabis would acknowledge its medical potential and encourage research. But that's not likely to happen. Keeping marijuana under schedule I, says DEA spokeswoman Dawn Dearden, is based on a lack of scientific evidence showing marijuana can be used safely and effectively as a treatment.

Meanwhile, patients like Dan Pope, 45, a Colorado resident with muscular dystrophy, continue their use of medical marijuana. He says it helps control his muscle spasms and makes his pain tolerable. But when he recently went to the Muscular Dystrophy Association, where he is a volunteer, to ask for support in reclassifying marijuana, he was turned down. There isn't enough research, he was told, to show that it works.


Marijuana as medicine is nothing new, despite the current groundswell of laws making pot legal for medical uses. Here's a quick fact file on cannabis and its medical history, makeup, and legality"

1. 'Marijuana" is a Mexican term that originally was applied to low-quality tobacco.

2. The plant was cultivated in China for therapy (and recreation) over 4,700 years ago.

3. More than 20 prescription medicines containing marijuana were sold in U.S. pharmacies at the turn of the 20th century. Pot-based medications were commonly available until 1942, when cannabis was stricken from the U.S. Pharmacopeia, the official compendium of drugs considered effective. From 1937 to 1942 the federal government collected a tax of $1 per ounce for such drugs.

4. About 17,000 studies on marijuana and its components have been published, according to the National Organization for the Reform of Marijuana Laws, an advocacy group, but fewer than 20, all of them small, have included human subjects.

5. The federal government is in the pot-growing business. Under a federal contract, the University of Mississippi in Oxford cultivates marijuana for use by researchers, who have to be cleared by the National Institute on Drug Abuse.

6. The plant has nearly 500 chemical compounds, called cannabinoids.

7. Fourteen states and the District of Columbia have legalized medical marijuana: Alaska, California, Colorado, Hawaii, Maine, Michigan, Montana, Nevada, New Jersey, New Mexico, Oregon, Rhode Island, Vermont, and Washington. But patients in these states face federal prosecution for using it -- or for growing or possessing pot for medical purposes.

8. Federal law prohibits physicians from prescribing or otherwise actively supplying patients with the drug. But in 2002 the U.S. Supreme Court backed an appellate court ruling that physicians who discuss it with patients, or provide oral or written recommendations, are protected.


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