SAN FRANCISCO — As more states embrace legalized marijuana, the drug’s growing medicinal use has highlighted a disturbing fact for doctors: scant research exists to support marijuana’s health benefits.
Smoked, eaten or brewed as a tea, marijuana has been used as a medication for centuries, including in the United States, where Eli Lilly sold it until 1915.
The drug was declared illegal in 1937, though its long history has provided ample anecdotal evidence of the plant’s potential medicinal use. Still, modern scientific studies are lacking.
What’s more, the federal government is scaling back its research funding.
U.S. spending has dropped 31 percent since 2007 when it peaked at $131 million, according to a National Institutes of Health research database. Last year, 235 projects received $91 million of public funds, according to NIH data.
That’s left the medical community in a bind: current literature on the effects of medical cannabis is contradictory at best, providing little guidance for prescribing doctors.
“What’s happening in the states is not related to science at all,” said Donald Vereen, a former adviser to the last three directors of the National Institute on Drug Abuse.
“It’s difficult to get good information,” said Beau Kilmer, co-director of RAND Corp.’s drug policy research center. Kilmer is also part of a group selected to advise the state of Washington on its legalization effort.
Two states, Washington and Colorado, have fully legalized the drug, 18 states allow its use for medical reasons and 17, including New York, have legislation pending to legalize it.
Vereen, the NIDA adviser, says that most doctors’ and policymakers’ knowledge on the subject stems from a 1999 report from the Institute of Medicine, an independent nonprofit that serves to provide information about health science for the government. The group summed up its findings saying cannabis appeared to have benefits, though the drug’s role was unclear.
The IOM report recommended clinical trials of cannabinoid drugs for anxiety reduction, appetite stimulation, nausea reduction and pain relief. It also found that the brain develops tolerance to marijuana though the withdrawal symptoms are “mild compared to opiates and benzodiazapines.”
“We don’t know that much more than what’s in that report,” said Vereen.
Vereen, for one, says marijuana’s effects on pain without the withdrawal symptoms associated with other medications are deserving of further study to develop better pain drugs.
Subsequent research suggests marijuana may help stimulate appetite in chemotherapy and AIDS patients, help improve muscle spasms in multiple sclerosis patients, mitigate nerve pain in those with HIV-related nerve damage and reduce depression and anxiety.
It’s even been suggested that an active ingredient, THC, may prevent plaques in the brain associated with Alzheimer’s, according to a 2006 study by the Scripps Research Institute.