The cannabis plant has been used as a medicine for thousands of years. In the United States, doctors could prescribe marijuana cigarettes to patients for a variety of conditions until the 1940s, when it was banned. Marijuana's status as an illegal drug has removed it from the official medical arsenal, but its therapeutic power is still attracting attention, especially its pain-killing properties. About 30 percent of HIV patients develop painful nerves during the course of their illness, and this neuropathy is extremely difficult to treat with standard pain medications. Dr. Donald Abrams, of the University of California at San Francisco,...
