POT STUDIES DIFFICULT TO ORGANIZE, ANALYZE

Advocates of medical marijuana tout its ability to alleviate the symptoms
of a number of diseases, from multiple sclerosis, glaucoma, epilepsy and
AIDS to nausea caused by chemotherapy. While experts say marijuana may be
promising, they note that there hasn't been enough solid research to prove
these claims.

"The evidence is just not there," says Stanley Watson, a University of
Michigan professor of psychiatry and one of two principal authors of a 1999
report by the Institute of Medicine (IOM), a private, non-profit
organization that advises the government on health policy. "The studies
that have been done have just not been well-enough designed."

Organizing a study of the health benefits of an illegal drug is a
challenge, says John Benson, the other principal author of the IOM report,
which called for more research into marijuana's possible medical benefits.
The American Medical Association in 2001 issued a statement that seconded
that call.

Marijuana's potential benefits are limited by the harm caused by smoking,
which can increase the risk of cancer, damage the lungs and cause pregnancy
complications, such as low birth weight, states the IOM report.

The IOM report found no conclusive data to support the idea that pot causes
people to take up harder drugs, or that approving it for medical use would
increase its use among the public.

Yet marijuana's medical benefits are often modest, Watson says. Almost all
breast cancer patients treated with a chemotherapy drug called cisplatin
become nauseated. Standard drugs can reduce that rate to 10%, while
marijuana lowers the number to only 25%. "If you have a family member with
this illness, what would you put them on?" Watson asks.

The Food and Drug Administration has approved a drug called Marinol -- a
form of THC, an active ingredient in marijuana -- to treat AIDS-related
weight loss as well as chemo-induced nausea. Benson says the drug, which
often produces a hangover, is not very popular.

Scientists have studied marijuana's effects on several ailments:

. AIDS. Research shows that marijuana stimulates the appetite among AIDS
patients, who often waste away. "Patients gained a little weight, and they
ate a lot of junk food," says Benson, who notes that sweets and snacks
don't improve nutrition.

. Glaucoma. Smoking marijuana should not be used to treat glaucoma,
according to the IOM report. Although it relieved eye pressure, those
effects were short-lived.

. Epilepsy and multiple sclerosis. There is "limited scientific evidence"
that marijuana produces any measurable medical benefits, according to an
article last year in Neurology.

The drug remains popular with some patients, however. In two Canadian
studies also published in Neurology, one found that 36% of 220 MS patients
used marijuana, while another article found that that 21% of 160 epilepsy
patients reported using marijuana in the past year. Of those epilepsy
patients, 68% say the drug made seizures less severe and 54% said seizures
were less frequent.

Scientists don't put much faith in reports from patients unless a drug's
effects can be measured by a physician, Benson says. Patients may feel
better not because of marijuana, but because of the "placebo effect," in
which ineffective drugs appear to produce results.