(3 of 4)
The A.M.A. issued a report last year summarizing the body of knowledge about medical marijuana. It's shockingly slim. Dr. Abrams in San Francisco has produced some of the clearest evidence to date of pot's therapeutic value. Even though his clinical trial was designed merely to investigate whether marijuana is safe for hiv patients, he also turned up data that anyone who ever had the munchies already knew: pot makes you hungry. Test subjects who smoked marijuana gained an average of 6.6 lbs. during the trial, compared with 2.4 lbs. for the group taking the placebo. Some other findings from the A.M.A. report:
Patients who are HIV-positive or undergoing chemotherapy can have trouble keeping food down, so anything that helps them eat is significant--though not necessarily for the reasons marijuana boosters think. Pot's ability to enhance appetite may have more to do with its high and less to do with any direct effects on nausea. Only 20% to 25% of patients in two 1980s trials could completely control vomiting with marijuana; other drugs work better for emesis. Still, the A.M.A. recommended more studies on marijuana for those who don't respond to the other drugs, and it notes that for those feeling sick, inhaling a substance may be more palatable than swallowing a pill.
Marijuana does reduce pressure on the eyeball, about 25%, but the drug isn't always practical as a glaucoma treatment. Many who have the disease are elderly and can't tolerate pot's tendency to raise heart rates.
Marijuana can help people with spasticity (extreme muscle tension) and tremor due to multiple sclerosis and trauma. But the drug hasn't been rigorously compared with the standard antispastic treatments.
In patients with postoperative pain, THC is more effective than a placebo, and some reports suggest smoking pot may reduce the need for highly addictive opioids. But the A.M.A. says better-designed studies are needed to properly evaluate pot as a painkiller. Several are under way. In California, five teams of researchers are conducting studies of marijuana as an analgesic, particularly for cancer and nerve pain.
The A.M.A. concludes that the lack of "high-quality clinical research ...continues to hamper development of rational public policy" on medical marijuana. Which raises the question, Why, after five millenniums, doesn't such research exist? Two possible answers: First, the government may have rejected cannabis studies to avoid any challenge to its view that pot is dangerous and medically useless. Second, pot may just be dangerous and medically useless.
The drug wasn't always so controversial in the scientific establishment. The U.S. Pharmacopeia, a doctors' listing of remedies begun in 1820, first included cannabis in 1870. The Pharmacopeia didn't drop pot until its 1942 edition, the first published after cannabis was outlawed in 1937. Eventually most physicians began to view the drug as little more than a crude intoxicant. They tended to favor new-fashioned drugs that were refined by pharmaceutical firms into pure chemicals. Raw marijuana contains some 400 compounds.
It wasn't until the '70s that modern methods were applied to test the medicinal effects of cannabis. As Earleywine recounts, a UCLA study designed to confirm police reports that pot dilates pupils found instead a slight constriction. That's how doctors discovered the drug could help glaucoma sufferers by reducing intraocular pressure. In the years after that discovery, 26 states opened therapeutic research programs.
But the Federal Government, which by then controlled the only legal supply of marijuana, had just passed the Controlled Substances Act of 1970. That law placed marijuana in Schedule I, the designation for drugs without valid medical use. State health officials found it difficult to persuade their federal counterparts to give them cannabis for research, as doing so would undermine the law, at least in spirit, by suggesting there were medical uses. (Only seven states got pot. One was Tennessee, which is why Al Gore's sister was able to try the drug before losing her battle with lung cancer in 1984.)