More than a quarter of U.S. adults suffering from chronic pain have turned to using cannabis to manage their discomfort, according to a new study published in JAMA Open Network.  Researchers at Michigan Medicine surveyed 1,661 adults last spring with chronic pain who lived in one of the 36 states with active medical cannabis programs and Washington, D.C. About 26 percent of survey participants reported using cannabis within the past year to manage pain, researchers found. Out of those people who said they consumed cannabis to help alleviate pain, more than half reported that the drug led to lower use of prescription opioids, nonopioids and over-the-counter pain medications.