First, because marijuana remains a federal Schedule I drug, research is severely restricted. However, there has been extensive research done in Europe and Israel. This research has shown multiple health benefits for those who take cannabidiol, or CBD, and a combination of CBD and THC, the main psychoactive ingredient of marijuana.
Article source: http://www.latimes.com/opinion/readersreact/la-ol-le-marijuana-research-20180717-story.html