Edward Maa did not plan to become a marijuana researcher. But a few years ago, when the neurologist and epilepsy specialist surveyed his patients about their use of alternative medicines, he discovered that more than a third had turned to marijuana to try to control their seizures. According to the Epilepsy Foundation of Colorado, the widely reported case of Charlotte Figi, a child whose nearly constant seizures were dramatically curtailed with cannabidiol, a marijuana ingredient, has helped trigger an influx of families from around the U.S. [into Colorado] seeking similar treatment for their children with seizure disorders. Maa wants to move beyond anecdote and into data. He is monitoring 150 epilepsy patients who all take a product derived from the same strain of marijuana that Figi used, provided by the same source. Although the federal government still lists marijuana as a Schedule I drug, a class with no currently accepted medical use," a body of recent research suggests that cannabinoids, which are the active ingredients in marijuana, may have medicinal uses even beyond the approved ones. They might protect the brain from the effects of trauma, ease the spasms of multiple sclerosis and reduce epileptic seizures. Further preliminary work indicates that the chemicals may slow the growth of tumors and reduce brain damage in Alzheimer's disease. Before World War II, marijuana was listed as a medicine in the country's encyclopedia of drugs, the United States Pharmacopeia.