As more states legalize marijuana, there's growing interest in a cannabis extract - cannabidiol, also known as CBD. It's marketed as a compound that can help relieve anxiety - and, perhaps, help ease aches and pains, too. CBD doesn't have the same mind-altering effects as marijuana, since it does not contain THC, the psychoactive component of the plant. There's good evidence to suggest that CBD could be an effective treatment of anxiety and addiction" and other disorders, says Dr. Esther Blessing, a psychiatrist and researcher at New York University. "But we need clinical trials." Small, short-term human studies ... suggest CBD exhibits anti-inflammatory and anti-anxiety properties. These preliminary findings piqued Blessing's interest. For instance, she points to a 2011 study of a few dozen people, some of whom had social anxiety disorder, who were asked to speak in front of a large audience. Researchers compared anxiety levels in people after they took CBD, compared to those who got the placebo or nothing at all. "People who took CBD reported significantly less anxiety" compared to those who got the placebo, Blessing says. Though CBD supplements are widely available for sale, a legal murkiness surrounds marijuana extracts. Even if you live in a state where marijuana use is legal, the federal Drug Enforcement Administration still classifies the CBD extract as a Schedule 1 substance - the DEA's most restricted category.